- s “ote ro tee om aes ease beaten i O° i oneeinges 60st mame . Digitized by the Internet Archive in 2010 with funding from University of Toronto http://www.archive.org/details/bulletin190113211 unit f Me ; Wt hw) i ih i (0 i Nari | He My SAXTY ste / pA HAetee [Arid 4 9% 44) sf / 4] are) Iw tuchey> D1 £9 , AnvoU Uthat Lng | nee“ (U. ef DEPARTMENT OeriGh CULTURE: BUREAU OF PLANT INDUSTRY}-BULLETIN NO, 21-2 2 ¢ B. T. GALLOWAY, Chief of Bureau. BACTERIOLOGICAL STUDIES OF THE SOILS OF THE TRUCKEE-CARSON IRRIGATION PROJECT. BY KARL F. KELLERMAN, Physiologist in Charge of Soil-Bacteriology and Water-Purification Investigations, AND E. R. ALLEN, Scientific Assistant. Issu—epD Aprit 15, 1911. ~ WeASeNn Grow: GOVERNMENT PRINTING OFFICE, 1 J a a aS Pee v 7 a: : ‘oe a4: : nae =e hat . ow * eh ae ; yf 7 ig a i es as = eet oe eT f eae) a i“ ¢é ‘ers o ee eit J 04 ~ . pene ‘® 7 ee i} Lay =. ea Ks no, Lie BUREAU OF PLANT INDUSTRY. Chief of Bureau, BEVERLY T. GALLOWAY. Assistant Chief of Bureau, WILLIAM A. TAYLOR. Editor, J. E. ROCKWELL. Chief Clerk, JAMES E. JONES. SorL-BACTERIOLOGY AND WATER-PURIFICATION INVESTIGATIONS. “ ScrENTIFIC STAFF. . Karl F. Kellerman, sc Sua in Charge. T. R. Robinson, Assistant Physiologist. \ I. G. McBeth, E. R. Allen, R. C. Wright, and Edna H. Faweett, Selentific A F. L. Goll and L. T. Leonard, Laboratory Aids. 211 2, ‘ — = LETTER OF TRANSMITTAL. U.S. DEPARTMENT OF AGRICULTURE, BuREAU OF PLANT INDUSTRY, OFFICE OF THE CHIEF, Washington, D. C., January 17, 1911. Str: I have the honor to transmit herewith a paper entitled “‘ Bac- teriological Studies of the Soils of the Truckee-Carson Irrigation Project” and to recommend that it be published as Bulletin No. 211 of the series of this Bureau. These investigations, though in many ways of a preliminary char- acter, indicate some of the possibilities of a bacteriological diagnosis of soils and will be of interest to all who have to deal with problems of soil fertility. Respectfully, ; Wan. A. TayLor, Acting Chief of Bureau. Hon. James WILson, Secretary of Agriculture. 211 3 CON TENTS. SERRE te es oS he BSE echoes tie eae eh oS ae ne Wis a eo ESE Methods employed in bacteriological investigations of the soil at Fallon, Nev-. Pe nCEMenta tbe MEL 24552 Seno ee Sol oc. AAA soles Sold PeeMETEER WOMEN ES, or, 6 Ser taroe SUE a betes een dale cb SE tie de & Nitrityine power of cols at different depths. <<. -s6).-:5222..--2.-5222-220..- imncwen ow samples in ‘solution... -.-.-..p022-5- 22 ee eee foe eee eee ee (2 LO UELLE DIN OU 02 2S Re AME Eeyore hod en Ya IE ete SAS nia cio See tio Relative numbers of bacteria in different soils..................-------.----- Detailed study of soil typical of extensive areas.............-.------------5- TIER TENE RT teins cts 9? Sa A, Sons oe bc La ns ode SE alee Fia. 1. ILLUSTRATIONS. Location of sampling plats in the experimental fields of the Truckee- Carson Experiment Farm, south of Fallon, Nev.........-.-.. . Diagram showing the ee of ammonium sulphate in anples a soil from different depths from plats 100 and 110, Truckee-Carson aps RPER ON GM SEN i ctr ie mina ingen cei BEE = ae, eye sie ote . Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plat 120, Truckee-Carson Experiment . Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plat 130, Truckee-Carson Experiment . Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plats 160 and 170, Truckee-Carson Bx pernnieih PALME. shoot at aee eo oni enigs ist aa we sas tae ee es os . Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plat 180 (poor soil) and plat 190 (good soil), Truckee-Carson Experiment Farm................--------+--- . Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plat 200, Truckee-Carson Experiment . Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plat 210, Truckee-Carson Experiment wo oo bo bo bt Oh OP WD iv) Page. 13 13 14 16 16 Fic. 9. 10. AY: 13. 4. 16. 18. 19: ILLUSTRATIONS. Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plat 220, Truckee-Carson Experiment Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plat 230, Truckee-Carson Experiment Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plats 240 and 250, Truckee-Carson Experiment Farm... 23. o2sesscee2 sane eee cece 2. Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plats 260 and 270, Truckee-Carson Experiment Farm... .---..2 2022+. -+020s2snse25<00o0 eer Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plats 280 and 290, Truckee-Carson Experiment Parm_. .2.. 2222. .2-5-120. 25.02 2256-5s <= 2 Diagram showing the relation between the quantity of alkali and the nitrification in samples of soil from plats 180, 190, 170, 150, 100, 160, 110, and 120, Truckee-Carson Experiment Farm. Samples taken from depths of 0 fo @meches.._...,.....-. ego. oe oe 5. Diagram showing the relation between the quantity of alkali and the nitrification in samples of soil from plats 180, 120, 170, 100, 190, 150, 160, and 110, Truckee-Carson Experiment Farm. Samples taken from depths of 6 to. 12 inches. ...-..2...2...-852-.5,5-3 42a Diagram showing the relation between the quantity of alkali and the nitrification in samples of soil from plats 180, 190, 170, 100, 120, 160, 110, and 150, Truckee-Carson Experiment Farm. Samples taken from depths of 12 to 18 inches_:-...:..-..22-2-.---.-<- nn . Diagram showing the relation between the quantity of alkali and the nitrification in samples of soil from plats 180, 170, 190, 100, 110, 160, 150, and 120, Truckee-Carson Experiment Farm. Samples taken from depths of 18 to 24 inches’.-......-2..-.2--) ane Eee Diagram showing the effect of calcium sulphate upon the nitrification of ammonium sulphate in samples of soil from plat 300, Truckee-Carson Experiment Farm, representing poor soil ‘‘A;’’ plat 310, representing poor soil ‘‘B;’’ and plat 320, representing good soil.............-..-- Diagram showing the ammonification of peptone in 7 days in samples of soil from plat 350 (good soil) and from plats 330 and 340 (poor soil), Truckee-Carson Experiment Farm... .:...:-.:.22. 222-5) = eee . Diagram showing the ammonification of peptone in 15 days in samples of soil from plat 350 (good soil) and from plats 330 and 340 (poor soil), Truckee-Carson. Experiment Farm .....:.....-22.-_<..2-5:2eeeeee 211 Page. 17 ie 18 ibs, 20 21 22° 23 23 29 30 31 B. P. I.—646. BACTERIOLOGICAL STUDIES OF THE SOILS OF THE TRUCKEE-CARSON IRRIGATION PROJECT. INTRODUCTION. In making a bacteriological study of any soil or group of soils there are certain fairly well defined groups of micro-organisms whose func- tions, although as yet imperfectly understood, are recognized as im- portant factors in crop production and are more or less familiar to everyone who has attempted to investigate the problems of soil fertility. These groups of micro-organisms may be roughly separated into four classes, depending upon their physiologic characteristics: (1) Parasites, or organisms important chiefly because they are patho- genic to animals or plants and are frequently found in soils; (2) the cellulose-destroying organisms; (3) the organisms associated with the formation of humus; and (4) the organisms associated with the trans- formation of soil nitrogen. Only those groups concerned with the transformation of nitrogen, which in the form of ammonia or nitrate is practically the most important of all plant foods, are reported upon at this time. The data sought in studies of this character may be outlined as follows: (1) Total numbers of saprophytic bacteria in measured quantities of soil. (2) Ammonification; the breaking down of nitrogenous organic matter into ammonia. (3) Nitrification; the oxidation of various compounds of nitrogen to nitrate. (4) Denitrification; the reverse of nitrification. (5) Nitrogen fixation, symbiotic and nonsymbiotic; the utilization of atmospheric nitrogen in forming nitrogenous organic compounds. Tn the work conducted at Fallon, Nev., during the season of 1909, in cooperation with the Office of Western Agricultural Extension, no quantitative study was made of nitrogen fixation, and the data on the subject of ammonification are very meager. Some preliminary inves- tigations in arid regions had shown that nitrification takes place here at considerable depth. All studies, therefore, were made of a 3-foot zone, keeping separate the samples of soils from different depths. The comparative nitrifying power of the different samples from the various plats is shown by curves, the parts per million of nitrogen as nitrate and nitrite being plotted as ordinates, and the different depths as abscissee. These curves show only the gain in nitric and nitrous nitrogen. Chlorids and sulphates are also shown, but seem to be of 211 7 8 SOILS OF THE TRUCKEE-CARSON IRRIGATION PROJECT. little importance. The quantity of nitric nitrogen originally present is shown in the legends under the diagrams (figs. 2-13). A description of the Truckee-Carson Experiment Farm, at Fallon, Ney., upon which practically all of the work herein reported was con- ducted, is given in a previous bulletin of this Bureau. The designa- tions of the small plats from which samples were taken for bacterio- logical study and their location are shown in figure 1. Fig. 1.—Location of sampling plats in the experimental fields of the Truckee-Carson Experiment Farm south of Fallon, Nev. METHODS EMPLOYED IN BACTERIOLOGICAL INVESTIGATIONS OF THE SOIL AT FALLON, NEV. REQUIREMENTS TO BE MET. Investigations in soil bacteriology require first of all the selection and development of satisfactory methods for determining the dis- tribution and activity of the micro-organisms which may occur under "Scofield, C. S., and Rogers, 8. J. The Truckee-Carson Experiment Farm. Bul- letin 157, Bureau of Plant Industry, 1909. 211 METHODS EMPLOYED IN BACTERIOLOGICAL INVESTIGATIONS. 9 different soil conditions. Though it is recognized that the methods suggested by different investigators are not adequate for accurate quantitative investigations of bacterial functions and conditions in various soils, the methods which at this time have been found most convenient and suitable for the investigations under discussion are briefly reviewed." COUNTS OF BACTERIA. Samples of soil were collected with as strict aseptic precautions as it is possible to observe under field conditions. Sterile salt-mouth bottles were used as containers, and the soil auger used for taking up the soil was carefully cleaned and flamed over an alcohol lamp before sampling each stratum. In the laboratory 1-gram portions were removed from the bottles with a sterile scoop which held the required quantity, transferred to 300 cubic centimeters of sterile water in 500-cubic-centimeter flasks, and the whole shaken thoroughly at short intervals for fifteen minutes. One-cubic-centimeter portions of these infusions were then removed with sterile pipettes and added to 10 cubic centimeters of melted beef agar, and plates poured in the ordi- nary manner and incubated at 28°C. Counts of bacteria were made at the end of five-day periods. AMMONITFICATION. Sterile peptone solutions having the following composition were inoculated with 5 per cent of soil and the ammonia determined at the end of seven and fifteen days by distillation with magnesia: LPL LLL Sates dee lee Sit a A ed ei oly Pare de a 15 grams. Wiponassmim, phosphates: se feet s Wie rete Ja as pes Fass at 3 grams Mooniesiinma sulphate 9c pen fe) 25228 el) Leet ey 2a ote ISTAMS Sipe lori ease. 2s te ee ae Ys ee OS orams Vi DUG cs Dele Shae aeee SF a al oie ee ee eres KIO eum 1 Lipman, J.G. Experiments on the Transformation and Fixation of Nitrogen by Bacteria. Twenty-fourth Annual Report, New Jersey State Agricultural Experiment Stations, 1903, pp. 217-285. Lipman, J. G., and Brown, Percy E. Methods Concerning Ammonia Formation in Soils and Culture Solutions. Report, Soil Chemist and Bacteriologist, New Jersey Agricultural College Experiment Station, 1908, pp. 95-105. . Lipman, J. G.,and Brown, Percy E. Noteson Methods and Culture Media. Report, Soil Chemist and Bacteriolégist, New Jersey Agricultural College Experiment Station, 1908, pp. 129-136. Lipman, J. G. Azotobacter Studies. Report, Soil Chemist and Bacteriologist, New Jersey Agricultural College Experiment Station, 1908, pp. 137-143. Léhnis, F. Ein Beitrag zur Methodik der bakteriologischen Bodenuntersuchung. Centralblatt fiir Bakteriologie, Parasitenkunde und Infektionskrankheiten, pt. 2, vol. 12, no. 6-8, pp. 262-267, June 24, 1904; no. 11-16, pp. 448-463, July 14, 1904; vol. 17, no. 14-16, pp. 518-528, December 7, 1906; vol. 20, no. 24-25, pp. 781-799, April 15, 1908; vol. 24, no. 5-7, pp. 183-192, August, 1909. Remy, Theodor. Bodenchemische und Bakteriologische Studien. Landwirt- schaftliche Jahrbiicher, vol. 35, Supplement 4, pp. 1-62. Berlin, 1906. 78011°—Bul. 211—11——2 10 SOILS OF THE TRUCKEE-CARSON IRRIGATION PROJECT. NITRIFICATION. Samples of soil were collected with the precautions previously described. In some cases 1-gram portions for counts of total num- bers of bacteria were removed from the bottle of soil and the remainder of the sample used for nitrification studies. Because of the great variation in the fertilty of different fields it was considered necessary to determine at what depths the nitrifying bacteria existed; therefore, instead of emptying the soil from the container and allowing it to dry, thus exposing it to some contamina- tion, one-half of the soil, approximately 50 grams, was removed with a sterile spatula and used for “original”? determinations. Five cubic centimeters of 0.4 per cent ammonium sulphate was then added to the portion remaining in the botvle and the sample placed in the incu- bator at 28°C. With the original moisture of the soil this additional 5 cubic centimeters frequently made the water content of the soil somewhat above optimum, but owing to the rapid evaporation in an arid climate this rapidly decreased and was adjusted as nearly as possible in subsequent waterings. All samples were weighed at 3-day intervals, and as any appeared to fall below optimum the required quantity of sterile distilled water was added to restore them. The incubation period was two weeks, the temperature being maintained at 28°C. The chemical work presented no little difficulty. The analytical determinations may be considered in two phases: (1) The prepara- tion of the aqueous extract of the soil both before and after imcuba- tion with ammonium sulphate and (2) the determination of nitrites and nitrates in original and incubated samples. In the preparation of the aqueous extract considerable difficulty was experienced. All of the soils used contained variable and fre- quently quite large proportions of very fine clay, which would not settle out and leave a clear supernatant liquid, even on prolonged standing. It was thought advisable to determine the chlorids and sulphates in the original samples; therefore the common salts con- taining these radicals could not be used to flocculate the clay, although this method was sometimes used in the examination of the samples after incubation where only nitrites and nitrates were deter- mined. Pressure-pump facilities were inadequate for the large num- ber of samples used, the more so as the fine clay particles clogged the porcelain filter and caused filtration to be extremely slow with the low pressure available.! Heating the sample in the oven at different temperatures previous to adding the water seemed to have no effect, so the supernatant liquid was first drawn off turbid, evaporated to dryness, baked at 90° to 100° C., and then filtered. In all of the ' Approximately 25 pounds to the square inch. 211 METHODS EMPLOYED IN BACTERIOLOGICAL INVESTIGATIONS. 11 baking experiments it was noticed that the nearer a set of samples was baked at 100° C. the better the subsequent filtering, probably indicating that the clay is siliceous. The Griess method is the standard for determining nitrites, but owing to the delay in getting chemicals at Fallon the potassium- iodid-starch method was used for a large part of the work. This method, while primarily a qualitative one, was found to be fairly reliable for quantitative determinations if a large quantity of reagent was used when the nitrites were high, as indicated by a rapid develop- ment of the blue-black color. The Grandval-Lajoux phenol-sulphonic acid method as modified by Syme! was used for estimating nitrates; before determining nitrates the nitrites were removed by urea in acid solution in accordance with Piccini’s method. Chlorids were frequently high in soil solutions in which nitrates were to be determined, and it was necessary to remove them when present in concentrations greater than 50 or 70 parts per million. This was accomplished by the use of silver sulphate. Chlorids* were determined by the Mohr “method, titrating the neutral solution with N/10 silver nitrate and using potassium chromate as an indicator. Sulphates? were determined by the turbidity method described by the Bureau of Soils. DENITRIFICATION. Studies of denitrification were made by inoculating Dunham’s peptone solution containing 0.2 per cent potassium nitrate with soil and with a Frost scale measuring roughly the quantity of free nitrogen evolved. Either ordinary fermentation tubes or test tubes inverted in salt-mouth bottles were used. The latter method is preferred, as it permits the use of larger quantities of soil for inoculations. | NITROGEN FIXATION. -Leguminous plants were examined for the presence of nodules, and Azotobacter cultures were isolated from soil samples. ‘Syme, W. A. The Colorimetric Determination of Nitrates in Soil Solutions Con- taining Organic Matter. Thirty-first Annual Report of the North Carolina Agricul- tural Experimént Station, for the Year Ending June 30, 1908, pp. 64-65. 2 Both of these salts were determined by Mr. C. A. Jensen, of the Office of Western Agricultural Extension of the Bureau of Plant Industry. 3 Schreiner, Oswald, and Failyer, George H. Colorimetric, Turbidity, and Titration Methods Used in Soil Investigations. Bulletin 31, Bureau of Soils, U. S. Dept of Agriculture, 1906. 211 12 SOILS OF THE TRUCKEE-CARSON IRRIGATION PROJECT. NITRIFYING POWER OF SOILS AT DIFFERENT DEPTHS. In investigations in soil bacteriology in the eastern United States only the surface soil shows great variations. The soil of the arid sections is much deeper, however; that is, the subsoil is less ‘‘raw’’ than in regions of heavier rainfall, a fact that has come to be more or less familiar to everyone studying soil conditions over extensive areas. Figure 2 shows the nitrification of samples from plats 100 and 110. These plats, which are practically duplicates, are in a productive DEPTH AT WHICH SAMPLES WERE TAKEN. i 67012” 1270 18” 87024” 247036" rs : N S X = é S S S * S S « e R S N PARTS PER MILLION OF CHLOR/DS AND SULFHATES. Fig. 2.—Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plats 100 and 110, Truckee-Carson Experiment Farm. Original nitrate present in samples from plat 100: Depth, 0 to 6 inches, 8 parts per million; 6 to 12 inches, 15; 12 to 18 inches, 9; 18 to 24 inches, 4.8; 24 to 36 inches, 6.56. From plat 110: Depth, 0 to 6 inches, 9 parts per million; 6 to 12 inches, 7.4; 12 to 18 inches, 5.2; 18 to 24 inches, 4.8; 24 to 36 inches, 3.12. alfalfa field which has been under cultivation for several years. The soil is loose and sandy throughout the 3-foot depth. The nitrate curves show that there is a gradual decrease in nitrifying power with depth. Figures 3 and 4 show the nitrification in samples from plats 120 and 130. These are in a fertile alfalfa field similar to the one mentioned 211 NITRIFYING POWER OF SOILS AT DIFFERENT DEPTHS. 18 2 it DEPTH AT WHICH SAMPLES WERE TAIAEW. 0'706 67012” 127018" 187024" 247036" x : KR S : ; 8) S = , S N N & : ; x X PARTS FER? SI/LL/ION OF CHLORIOS AND SULPHATES. Fig. 3.—Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plat 120, Truckee-Carson Experiment Farm. Original nitrate present in samples: Depth, 0 to 6 inches, 15.36 parts per million; 6 to 12 inches, 8.64; 12 to 18 inches, 6.72; 18 to 24 inches, 3.84; 24 to 36 inches, 2.88. in the previous paragraph. The samples from plat 120 show nitrifica- tion varying rather irregularly with depth. Samples from plat 130 DEPTH AT WHICH SAMPLES WERE TAKEN. O706" = 67012” 127018” 187024" 247036” CHLORIDS ANO SULPHATES. MITROGEN AS NITRATES. FARTS PERIILLION OF | A4AATS FER MILLION OF Fig. 4.—Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plat 130, Truckee-Carson Experiment Farm. Original nitrate present in samples: Depth, 0 to 6 inches, 13.3 parts per million; 6 to 12 inches, 6.72; 12 to 18 inches, 9.6; 18 to 24 inches, 7.23; 24 to 36 inches, 14.4. 211 14 SOILS OF THE TRUCKEE-CARSON IRRIGATION PROJECT. practically failed to nitrify,! although the two plats appear to be very similar. Figure 5 shows the relative nitrifying power of good and poor soils collected from adjoining plats. Plat 160 has a loose sandy soil to a _ ., DEPTH AT WHICH SAMPLES WERE 7AKE/. O76" 67012" 127018" 187024" 247036" 1000 900 800 700 600 500 400 \ ry Ae PARTS FEF MILLION OF NITROGEN AS NITAKATES. FARTS PER /ALLION OF CHLORIDS AND SULFHATES. Fic. 5.—Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plats 160 and 170, Truckee-Carson Experiment Farm. Original nitrate present in samples from plat 160: Depth, 0 to 6 inches, 8.64 parts per million; 6 to 12 inches, 2.88;12 to 18 inches, 4.8; 18 to 24 inches, 6; 24 to 36 inches, 4.8. From plat 170: Depth, 0 to 6 inches, 4.32 parts per million; 6 to 12 inches, 6; 12 to 18 inches, 3.84; 18 to 24 inches, 3.6; 24 to 36 inches, 3. depth of 18 inches; below this it is very heavy, but below 26 and 30 inches it is again lighter in texture. At the time of sampling, this plat was supporting a fine growth of alfalfa. Plat 170 is in the north- east corner of the same field, and was very similar except that the This field had been irrigated a short time before the samples were collected. 211 all NITRIFYING POWER OF SOILS AT DIFFERENT DEPTHS. ug surface was a little more compact and the alfalfa was practically a failure. The nitrification curves show the same general variations, but the one of the poor soil is consistently below that of the productive soil. DEPTH AT WHICH SAMPLES WERE TAKEN. 67012" 127018" 187024" 247036" PARTS PER MILLION OF CHLOAIDS AND SULPHATES. ) : S = 3) X = g 8 = S S N S & N E N Fic. 6.—Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plat 180 (poor soil) and plat 190 (good soil), Truckee-Carson Experiment Farm. Original nitrate present in samples from plat 180: Depth, 0 to 6 inches, 2 parts per million; 6 to 12 inches, 3.5; 12 to 18 inches, 8.25; 18 to 24 inches, 4.5; 24 to 36 inches, 25.75. From plat 190: Depth, 0 to 6 inches, 4.5 parts per million; 6 to 12 inches, 15.75; 12 to 18 inches, 11.25; 18 to 24 inches, 20.75; 24 to 36 inches, 21.75. Plats 180 and 190 are located upon poor and good spots. The texture of the samples is very similar, both being sandy, but the surface of plat 180, the unproductive soil, is hard and compact as if 211 16 SOILS OF THE TRUCKEE-CARSON TRRIGATION PROJECT. held together by some cementing material. As shown in figure 6, the nitrifying power of samples from plat 180 is almost nothing. In this figure the chlorid and sulphate curves are of interest, as those of plat 180, the poor soil, are far above those of plat 190, the good soil.’ © |, DEPTH AT WHICH SAMPLES WERE TAKEN. Se 0706 67012 127018 18 7024 247036 200 4 S loo NK yo S NS ss NY cfs o &S VO a) % Ye -100 CK & tS = Xs x Fic. 7.—Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plat 200, Truckee-Carson Experiment Farm. Original nitrate present in samples: Depth, 0 to 6 inches, 7.68 parts per million; 6 to 12 inches, 5.8; 12 to 18 inches, 3.93; 18 to 24 inches, 4.32; 24 to 36 inches, 1.82. Figures 7 to 10, inclusive, show the nitrifying power of samples of soil from plats 200, 210, 220, and 230. They are in fields which have only recently been leveled and irrigated; in fact, 1909 was the first year they had been cropped. They produced a fair crop of barley, but the DEPTH AT WHICH SALTIFLES WERE TAKEN. R % a O06" 67012" I27018” 18'7024" 247036" i N S as Ne NS 10 NE N> RN Sl oa ee Sx eX O x We KS : 83 Re-10 : NS < XS Fic. 8.—Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plat 210, Truckee-Carson Experiment Farm. Original nitrate present in samples: Depth, 0 to 6 inches, 2.66 parts per million; 6 to 12 inches, 4.8; 12 to 18 inches, 4.16; 18 to 24 inches, 3; 24 to 36 inches, 2. young alfalfa sown in the barley was doing only fairly well. The curves from all of these*plats show a very low nitrifying power, yet a lance at the figures shows that nitrates were present in moderate quantities in the original samples. | Bridge readings on these samples were made by Mr. Jensen. 211 NITRIFYING POWER OF SOILS AT DIFFERENT DEPTHS. 17 Figures 11 and 12 present the results obtained from samples of soil from plats 240, 250, 260, and 270. The fields in which these plats are _ DEPTH AT WHICH SAMPLES WERE TAKEN. O7o6' 67012” 12'7018" 187024" 247036" PARTS PEP MILLION OF WITROGEN AS NITRATES. PARTS PER MULLION OF CHLORIOS AND SULPHATES. Fic. 9.—Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plat 220, Truckee-Carson Experiment Farm. Original nitrate present in samples: Depth, 0 to 6 inches, 7.68 parts per million; 6 to 12 inches, 6.91; 12 to 18inches, 10; 18 to 24inches, 5.64; 24 to 36 inches, 6. located have been merely leveled and left fallow, receiving regular applications of irrigation water. The field containing plats 240 and 250 is never cultivated, while that containing plats 260 and 270 is DEPTH AT WHICH SAMPLES WERE TAKEN. 67012" 127018" 187024" 24'r0 36" PARTS PER MILLION OF CHLORIOS AND SULPHATES. re) R x 8 S 3 N 8 S - S S N S x & x Fic. 10.—Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plat 230, Truckee-Carson Experiment Farm. Original nitrate present in samples: Depth, 0 to 6 inches, 10 parts per million; 6 to 12 inches, 8.16; 12 to 18 inches, 5; 18 to 24 inches, 4.56; 24 to 36 inches, 9.6. cultivated according to thorough summer-fallow methods. As the conditions are abnormal it is not surprising that the curves of chlorids 78011°—Bul. 211—11——_3 18 SOILS OF THE TRUCKEE-CARSON IRRIGATION PROJECT, and sulphates, as well as the curve showing nitrification, should be so erratic and variable. Figure 13 shows the nitrifying power of samples from plats 280 and DEPTH AT WHICH SAMPLES WERE TAHEN. 67012” 127018” 187024” 247036" % S S = % x = $ S = S S N S & & : N PARTS PER /ULLION OF CHLORIDS AND SULFHATES. Fig. 11.—Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plats 240 And 250, Truckee-Carson Experiment Farm. Original nitrate present in samples from plat 240: Depth, 0 to 6 inches, 6.8 parts per million; 6 to 12 inches, 8; 12 to 18 inches, 10.4; 18 to 24 inches, 6; 24 to 36 inches, 5. From plat 250: Depth, 0 to 6 inches, 28 parts per million; 6 to 12 inches, 48; 12 to 18 inches, 6; 18 to 24 inches, 5.2; 24 to 36 inches, 7. 290, located in an old alfalfa field just north of Fallon. These soils are very productive, and it was expected that they would show a greater nitrifying power than they did. This may possibly be 211 NITRIFICATION OF SAMPLES-IN SOLUTION. 19 explained, however, by the original high nitrate content of the soil, as there is often a tendency for the nitrifymg power of a soil to decrease as nitrates accumulate. NITRIFICATION OF SAMPLES IN SOLUTION. In order to further test for the presence of nitrifying bacteria and also to study some of their characteristics, inoculations were made DEPTH AT WHICH SAMPLES WERE JAKEN. O706" 67012” 127018” 187024" 247036” PARTS FER /4/LL/0N OF CHLOAIDS. 8 N R S % * = g 8 = S = N N S & w : x Fic. 12.—Diagram showing the nitrification of ammonium sulphate in samples of soi] from different depths from plats 260 and 270, Truckee-Carson Experiment Farm. Original nitrate present in samples from plat 260: Depth, 0 to 6 inches, 62 parts per million; 6 to 12 inches, 30; 12 to 18 inches, 18.75; 18 to 24 inches, 35.7; 24 to 36 inches, 30. From plat 270: Depth, 0 to 6 inches, 100 parts per million; 6 to 12 inches, 27.7; 12 to 18 inches, 50; 18 to 24 inches, 40; 24 to 36 inches, 50. into media consisting entirely of inorganic material which is not suit- able for the growth of saprophytic bacteria.t_ Curves have not been plotted from the data thus obtained, as the conditions were too abnormal to warrant considering the differences from a quantitative 1 Winogradsky and Omelianski’s Fluid Culture-Medium for Isolating the Nitrate Bacteria from Soils, and Winogradsky and Omelianski’s Fluid Culture-Medium for Isolating the Nitrite Bacteria from Soils. Centralblatt fiir Bakteriologie, Parasiten- kunde und Infektionskrankheiten, vol. 5, pt. 2, 1899, pp. 537-549. 211 20 SOILS OF THE TRUCKEE-CARSON IRRIGATION PROJECT. standpoint. The results are all expressed in Table I as parts of nitrogen per million of the solution. DEPTH AT WHICH SAMPLES WERE TAKEN. 0706" 67012” 127018” 187024" 247036" Ky : S = : S : — = ‘ 8 N : : 8 : PARTS FER MILLION OF SULPHATES. Fic. 13.—Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths from plats 280 and 290, ee Carson Experiment Farm. Original nitrate present in samples from plat 280: Depth, 0 to 6 inches, 12 parts per million; 6 to 12 inches, 10; 12 te 18 inches, 6; 18 to 24 inches, 15; 24 to 36 inches, 62.5. From plat 290: Depth, 0 to 6 inches, 60 parts per million; 6 to 12 inches, 60; 12 to 18 inches, 55.4; 18 to 24 inches, 60; 24 to 36 inches, 60. TasLe I.— Nitrification in solution of samples of soil from plats 100, 110. 180, 190, 220, 260, 270, and 280,1 Truckee-Carson Experiment Farm. Incubated at 28° C. — - = _— — ——— — Ammonia to nitrite| Nitrite to nitrate | Spar million illi = Noi) epth (parts per million).?| (parts per million) plat. of soil. ; 6 days. 12 days. | 10 days. | 20 days. | Inches. 100 0-6 6. 50 25 91. 60 96. 00 6-12 5. 00 25 64. 80 60. 00 12-18 6. 50 18 86. 40 81. 60 110 0-6 . 50 Lt) p22 eee 6-12 3. 25 2005/2302. 3S ol eee ae 12-18 8. 00 25 "| ccc ccnee Saleen nee 180 0-6 0. 00 15 }| 2400 86. 40 6-12 0. 00 1b) 3. 60 2. 40 12-18 0. 00 00 2. 40 3. 00 190 0-6 1.00 16 72. 00 74. 00 220 0-6 0. 00 00 13. 20 80. 00 6-12 0. 00 00 | 3. 60 5. 32 12-18 0. 00 00 2. 40 5. 60 260 0-6 5. 00 17 76.80 | 74.00 6-12 3. 00 10 57. 60 54. 40 12-18 3. 00 10 2. 88 17. 55 270 0-6 6. 50 20 9. 60 43. 20 6-12 0. 00 00 8. 64 60. 00 2851 0-6 ofa 20 21. 60 81. 60 6-12 1. 00 20 40. 80 81. 60 12-18 1. 00 20 38.40 | 81. 60 t 4 = —— 1 Plat 280 is located in an old alfalfa field one-fourth mile north of F allon. 2 Used medium for isolating nitrite bacteria. 3 Used medium for isolating nitrate bacteria. 211 CHLORIDS AND SULPHATES. ia | Tt will be seen that the nitrifiers and especially the nitrate bacteria develop quite well in solutions. It should be noted that the only samples that failed to produce nitrites were those taken at 6-inch, 12-inch, and 18-inch depths from plat 220, which failed to nitrify in soil. (See fig.9.) This soil, however, paduecd nitrates quite readily. This suggests the possibilty that the lack of nitrification in this soil may be due to lack of nitrite bacteria. CHLORIDS AND SULPHATES. In alkali studies it is recognized that as a rule the chlorid type is more injurious to ordinary farm crops than the sulphate type. Further, in some investigations in the soils of the arid regions it has been fond PLATS. PARTS PEP MILLION OF NITROGEN AS NITRATES. PARTS PEP 14/LL/0N OF CHLORIOS AND SULPHATES ZZ e iz ot / n/ = Fic. 14.—Diagram showing the relation between the quantity of alkali and the nitrification in samples of soil from plats 180, 190, 170, 150, 100, 160, 110, and 120, Truckee-Carson Experiment Farm. Samples taken from depths of 0 to 6 inches. that high nitrates correlate with the sulphate type, while low nitrates are usually associated with the chlorid type. It was thought, there- fore, that it would be of interest in connection with this work to study the relation of chlorids and sulphates to the nitrifying power. In plotting these curves the different plats are arranged in such an order that the nitrification of ammonium sulphate by the dif- ferent samples, which is the index of the difference of their powers of nitrification, forms an ascending series. Four diagrams are pre- sented (figs. 14 to 17), one for each depth from which samples of soil were taken. Figure 14, representing the surface samples, shows no relation between the concentration of soluble salts and nitrifying power. Figures 16 and 17, representing the deeper samples, are 211 22 SOILS OF THE TRUCKEE-CARSON IRRIGATION PROJECT. not in close agreement, although high alkali consisting of both chlorids and sulphates is apparently correlated with low nitrification. Little if any difference is to be noted between the effect of the chlorid and the sulphate types of alkali. DENITRIFICATION. In order to test for the presence of denitrifying bacteria several inoculations were made into Dunham’s solution containing 0.2 per PLATS. 00 NITRATES. PARTS PER MILLION OF CHLORIDS AND SULPHATES. ry xX g 0) N = 2 S S N N & & 8 x Fig. 15.—Diagram showing the relation between the quantity of alkali and the nitrification in samples of soil from plats 180, 120, 170, 100, 190, 150, 160, and 110, Truckee-Carson Experiment Farm. Samples taken from depths of 6 to 12 inches. cent of potassium nitrate, and the free nitrogen gas evolved was measured. This medium favors the growth of this class of bacteria. The conditions thus produced are abnormal and the quantitative differences shown in Table II should not be taken too seriously. It will be seen from the table that denitrifying bacteria are present and active in almost all of the soils tested. 211 DENITRIFICATION. 23 PLATS. 100 120 “NI oO ° fo) wo to) o> id a a 9 ° gpol4? = aoe af? PARTS PEP PULLION OF CHLOFIDS AND SULPHATES. FARTS PER MILLION OF NITROGEN AS NITRATES. Fic. 16.—Diagram showing the relation between the quantity of alkali and the nitrification in samples of soil from plats 180, 190, 170, 100, 120, 160, 110, and 150, Truckee-Carson Experiment Farm. Samples taken from depths of 12 to 18 inches. {70 i) nm un Ss a ro) 62. w a oO Ni ol FARTS PER MILLION OF CHLORIDS AND SULPHATES. i) : s S X RN 8 s S 0 S 8 N S : : N Fig. 17.—Diagram showing the relation between the quantity of alkali and the nitrification in samples of soil from plats 180, 170, 190, 100, 110, 160, 150, and 120, Truckee-Carson Experiment Farm. Samples taken from depths of 18 to 24 inches. ; 211 24 SOILS OF THE TRUCKEE-CARSON IRRIGATION PROJECT. Tape Il.—Denitrification in solution of samples of soil from plats 180, 190, 250, 260, 270, 280,‘ and 290,' Truckee-Carson Experiment Farm. | No. of Depth of |Gas formed Gas formed plat. soil. in 7 days. | in 15 days. | aa Inches Per cent. Per cent. 180 0-6 25 2é 6-12 20 30 | } 12-18 20 25 | 190 0-6 22 32 | 6-12 30 40 12-18 32 42 230 0-6 20 30 6-12 21 30 12-18 20 | 35 | 260 0-6 40 | 53 6-12 iG) 23 | 12-18 20 30 270 0-6 20 | 30 | 6-12 20 30 12-18 20 | 30 280 ! 0-6 00 00 6-12 Trace Trace 12-18 Trace Trace 290! 0-6 22 40 6-12 10 18 12-18 45 62 1 Plats 280 and 290 are located in an old alfalfa field one-fourth mile north of Fallon. RELATIVE NUMBERS OF BACTERIA IN DIFFERENT SOILS. An estimation of the number of bacteria in a gram of soil that would develop aerobically upon beef agar was made for many of the sampling plats in accordance with the method previously described, the results of which are shown in Table III. In accord with the reports of other investigators,! the data presented in Table III clearly show that the numbers of bacteria found in the different samples bear no consistent relation to the fertility or crop-producing power of the respective fields. No attempt was made to determine the relative numbers of proto- zoa in samples of soil from the good and poor areas. If the develop- ment of protozoa is determined by their food supply,? in other words, by the numbers of bacteria existing in the soil, it is obvious that in this region the crop-producing power can not be limited * by the abundance of protozoa. ' Léhnis, F. Ein Beitrag zur Methodik der bakteriologischen Bodenuntersuchung. Centralblatt fiir Bakteriologie, Parasitenkunde und Infektionskrankheiten, pt. 2, vol. 12, no. 6-8, June 24, 1904, pp. 262-267. Chester, Frederick D. The Bacteriological Analysis of Soils. Bulletin 65, Dela- ware College Agricultural Experiment Station, March 1, 1904. Voorhees, Edward B., and Lipman, Jacob G. A Review of Investigations in Soil Bacteriology. Bulletin 194, Office of Experiment Stations, U.S. Dept. of Agriculture, October 26, 1907. * Russell, E. J., and Hutchinson, H. B. The Effect of Partial Sterilization of Soil on the Production of Plant Food. Contributions from the Laboratory of the Rotham- sted Experimental Station, October, 1909, pp. 111-144. * Hall, A.D. The Fertility of the Soil. Science, n. s., vol. 32, no. 820, September 16, 1910, pp. 363-371. 21] DETAILED STUDY OF SOIL TYPICAL OF EXTENSIVE AREAS. 25 TaBLE III.—Number of bacteria per gram of soil and nitrifying power of samples from plats 10, 20, 30, 40, 180, 190, 290,' 240, 260, and 270, Truckee-Carson Experiment Farm. “ohn ; attuiyene umber o power o No. at peut of] bacteria per | soils (parts| Character of soil. Diet : gram. per mil- lion) Inches 10 0-6 435, 000 4.4 Very poor. | 6-12 251, 000 2.0 12-18 26, 650 0 18-24 146, 250 3.0 24-36 1, 000 .0 20 0-6 19, 500 54,2 Very productive. 6-12 11, 250 6.8 Good growth of 12-18 30, 000 1.0 alfalfa. 18-24 4, 500 0 24-36 3, 000 .0 30 0-6 160, 000 3.0 Poor and com- 6-12 65, 000 .0 pact. 12-18 262, 000 0 18-24 19, 855 0 24-36 10, 000 .0 40 0-6 210, 000 20. 4 Productive. 6-12 20, 000 4.0 Good growth of 12-18 135, 000 1.0 alfalfa. 18-24 45, 000 0 24-36 1,000 0 180 0-6 60,000 4.72 | Very poor. 6-12 175, 000 1.54 Alkali high. 12-18 180, 000 4.32 (See fig. 6.) 18-24 4, 000 2.54 190 0-6 3, 600 36. 30 Productive. 6-12 168, 000 37. 45 12-18 1, 554, 000 12. 75 18-24 704, 000 12. 25 290! 0-6 273, 000 30.00 | Productive. 6-12 396, 000 20. 00 Old alfalfa field. 12-18 262, 500 14. 60 (See fig. 13.) 18-24 327, 000 4.00 240 0-6 52, 000 69.00 | Fallow. (See 6-12 78, 700 4.50 fig. 11.) 12-18 56, 000 40 260 0-6 81, 000 18.00 | Fallow. (See 6-12 153, 300 40. 00 fig. 12.) 270 0-6 72, 000 100. 00 6-12 2,790, 000 92. 30 | 1 Plat 290 is located in an old alfalfa field one-fourth mile north of Fallon. DETAILED STUDY OF SOIL TYPICAL OF EXTENSIVE AREAS. Plats 300 to 350 are representative of a somewhat extensive type of soil of the Truckee-Carson project. This soil is very unproductive as a rule, almost barren in many cases, yet all through it, wherever properly leveled and irrigated, are spots of a few square rods in area that are normal and productive. The difference between these two conditions seemingly can not be explained by any of the now known causes of infertility. There is a certain difference in texture, or rather in the physical properties; the productive soil is loose and sandy, while the unproductive type, although sandy, contains a small quan- tity of clay which when shaken up with water remains suspended indefinitely and the soil cements on drying. These physical differ- ences, while no doubt factors, do not seem adequate causes of the extremely low fertility. The total alkali content is not high enough 211 26 SOILS OF THE TRUCKEE-CARSON IRRIGATION PROJECT. to produce toxic effects, and a lack of mineral plant food in the virgin soils is almost out of the question. Both soils are low in organic matter, as are all arid soils. Good soil management in other somewhat similar regions would indicate that the addition of organic matter to these soils in the form of barn- yard manure or green manure should produce benefieial physico- chemical effects, and such treatments have been applied somewhat extensively as a matter of experiment during the last two or three years. The poor soil apparently has not been benefited to a noticea- ble degree. The good soil has been somewhat improved, although even here the improvement has not been striking. A minute field examination of these good and poor spots a year or more after they had received applications of organic matter revealed a remarkable difference; all traces of the organic material had disappeared from the fertile spots, while the larger part of the manure added to the infertile spots was in an almost perfect state of preservation. Another peculiar difference was that in the poor spots, at depths of 6 to 28 inches, an irregularly distributed, dark-colored, foul-smelling layer was found, undoubtedly due to the presence of a peculiar organic decomposition product, while such a layer was never found associated with good soil. It should not be inferred from this description that this black layer was found only where organic matter has been added as a treatment; it was quite generally distributed through these infertile soils and is presumably due to the decay of such material as was turned into the soil when it was first reclaimed, such as sagebrush, greasewood, rabbit brush, and other desert plants, together with the roots of these plants which have been accumulating for long periods of time. Laboratory samples showed that this black substance was easily oxidized, for when a sample was taken to the laboratory, dried, and subsequently moistened for physiological experiments, all traces of the black color and peculiar odor disappeared. These unusual conditions of the decay of organic matter are neces- sarily somewhat closely associated with improper bacteriological conditions; that is, the improper utilization of organic fertilizers is due either to an improperly balanced or incomplete bacterial flora or to physical or chemical conditions preventing the performance of the normal activities of the bacteria present. Titrations of some of the aqueous extracts indicated that sodium carbonate (black alkali) was present in the poor soils but not in the good soils. It was also apparent that calcium sulphate and gypsum, when applied in large quantities, produced a decided effect in floc- culating the finely divided or colloidal clays. Samples were collected with a sterile spatula from the sides of freshly dug holes and placed in sterile containers. Portions of these samples were inoculated into 211 DETAILED STUDY OF SOIL TYPICAL OF EXTENSIVE AREAS. 27 Winogradsky’s solutions and also into flasks of sterile water, from which counts were made. The remaining portions of the samples were then emptied on clean sheets of paper in the culture room and left to dry under conditions as free as possible from chance contami- nations. Fifty-gram portions from each sample were removed for original nitrate determinations, and another equal portion was re- placed in the original containers, brought up to optimum moisture content with 5 cubic centimeters of 0.4 per cent sulphate of ammonia and distilled water, incubated for two weeks at 28° C., and the nitri- fication determined. A duplicate series to which was added a 2 per cent solution of calcium sulphate was prepared. At the beginning of the incubation period the total weight of the container and soil at optimum moisture was taken, and the loss from evaporation was restored with sterile distilled water at 3-day intervals during the incubation period. The results of the experiment appear in Tables IV and V. TasLe 1V.—E£ffect of calcium sulphate upon nitrification in samples of soil from plats 300 and 310, Truckee-Carson Experiment Farm, representing poor soil conditions. Incubated 15 days at 28° C. NO CALCIUM SULPHATE ADDED TO SAMPLES. Nitrogen as nitrite (parts per | Nitrogen as nitrate (parts per No. of | Depth of million). million). plat. soil. Ses 25 Bese Le Original.| Final. Gain. | Original.| Final. Gain. Inches 300 0-6 1.2 5. 60 4.40 9.12 56. 40 46. 28 6-12 2.0 3.12 1.12 7.68 00. 00 — 7.68 12-18 1.2 1.68 -48 6.14 00. 00 — 6.14 18-24 -0 1.20 1.20 4.56 00.00 | — 4.56 310 0-6 1.0 7. 28 6. 28 4.80 96.00 | 91.20 6-12 1.0 2.10 1.10 1.60 00. 00 — 1.60 12-18 | 1.0 - 80 — .20 4.32 00.00 — 4.32 18-24 | 1.0 1.20 - 20 3.07 00. 00 — 3.07 WITH 2 PER CENT CALCIUM SULPHATE ADDED TO ALL SAMPLES. 300 0-6 1.2 2.80 1.60 9.12 57.00 47.88 | 6-12 2.0 2.80 - 80 7.68 00. 00 — 7.68 12-18 1.2 2.70 1.50 6.14 00. 00 — 6.14 18-24 -0 - 88 - 88 4. 56 00. 00 — 4.56 310 0-6 1.0 4.00 3.00 4.80 96. 00 91.20 | 6-12 130 2.40 1.40 1.60 1.20 — .40 12-18 1.0 1.68 68 4.32 0.00 4.32 18-24 1.0 1.56 56 3.07 0.00 — 3.07 28 SOILS OF THE TRUCKEE-CARSON IRRIGATION PROJECT. TasBLe V.—Efect of calcium sulphate upon nitrification in samples of soil from plat 320, Truckee-Carson Experiment Earm, representing good soil conditions. 15 days at 28° C. NO CALCIUM SULPHATE ADDED TO SAMPLES. ' WITH 2 320 Nitrogen as nitrite (parts per | Nitrogen as nitrate (parts per million). million). Depth of soil. | = = —=|'= his rx | Original.| Final. Gain. | Original.) Final Gain Inches. 0-6 1.4 4.00 2.60 3.84 . 64 76.80 6-12 1.5 1.20 — .30 18. 24 76.80 58. 56 12-18 -0 1.60 1.60 15.90 5.00 —10.90 18-24 8 1.40 - 60 15.36 0.00 —15.36 Incubated PER CENT CALCIUM SULPHATE ADDED TO ALL SAMPLES. The gain in nitrates, or the soil, is shown in figure 18. These experiments on nitrification indicate that the difference in productiveness is not due to a suspension of nitrification, and also that it is not due to the presence of sodium carbonate, as the addition of calcium sulphate to the samples had absolutely no effect; the treated and untreated samples could really be considered duplicates. It would seem also that the infertility or the lack of decay of organic substances is not due to lack of air. 00 | 3.60 | 3.84 68 -13 | 18.24 82 1.82 15.90 60 — .20 15.36 81.60 76.80 4.56 - 00 77.76 58. 56 —11.36 —15.36 | nitrifying power of these samples of It might be argued that lab- oratory conditions were not such as would favor the compacting or cementing of the samples, yet it must be remembered that the corn- field containing plats 300, 310, and 320 was kept well cultivated and no crust was allowed to form during the growing season. VI and VII show the nitrification of the different samples in Wino- gradsky and Omelianski’s media. Tables Taste VI.—Nitrite formed from ammonia by samples of soil from plats 330, 340, and 350, Truckee-Carson Experiment Farm, in medium for nitrite bacteria. HE RIN Cy Nitrite | Nitrite No.of | Depth of formed in formed in lat. | of soil Sdays | 10 days eke * | (parts per (parts per million). | million). Inches 330 0-6 0.0 4.8 6-12 0 .0 12-18 504 .0 18-24 -O | .0 340 0-6 9.6 10. 4 6-12 12.8 12.8 12-18 12.8 12.8 18-24 .0 12.2 350 0-6 -O | Trace. 6-12 .0 4.8 12-18 .0 .0 18-24 .0 .0 Charac- ter of soil. Poor. Do. Good. Incubated DETAILED STUDY OF SOIL TYPICAL OF EXTENSIVE AREAS. 29 FARTS PEP M/LL/0N OF NITROGEN AS N/ITAATES. Tite DEPTH AT WHICH SAMPLES WERE TAKEN O06" 67012” 127018” 185024” | Fic. 18.—Diagram showing the effect of calcium sulphate upon nitrification of ammonium sulphate in samples of soil from plat 300, Truckee-Carson Experiment Farm, representing poor soil ‘‘A”’; plat 310, representing poor soil ‘‘B’’; and plat 320, representing good soil. TasLe VII.—Nitrate formed from nitrite by samples of soil from plats 330 and 350, Truckee-Carson Irrigation Project, in medium for nitrate bacteria. Incubated at 28° C. | , nlbeate No.of | Depth of| “SQ Gave. plat. soil. 10 days | (parts per million). | Inches 330 | 0-6 24. 00 6-12 19. 68 12-18 12. 60 18-24 19. 80 350 0-6 12. 50 6-12 24. 00 AZNS) Weve = eee 18-24 4.12 Nitrate formed in | 20 days (parts per million). Charac- ter of soil. Poor. Good. 211 30 SOILS OF THE TRUCKEE-CARSON IRRIGATION PROJECT. The fact that nitrification was feeble in the good soil and also in one of the poor soils should not be overemphasized, for soils that will nitrify under normal conditions frequently fail to do so in solutions. On the other hand, the rapidity with which the nitrate bacteria worked in solutions, even when they failed to do so in the soil, is interesting and almost without parallel. It is not surprising that a soil should fail to nitrify in solution, but it is remarkable that samples which failed to nitrify when kept warm and moist—ideal conditions for nitrification—should produce nitrates rapidly when inoculated into solutions. The production of ammonia from organic material by soil bacteria furnishes a means of measuring the power of the soil flora to break down nitrogenous organic substances. Thus it would seem that the soils of the plats in which organic matter remained indefinitely in a DEPTH AT WHICH SAMPLES WERE TAKEN. O70 6” 12'r0 1g” THOGEN AS AMMONIA. / N S N = : Wy & g N. Fig. 19.—Diagram showing the ammonification of peptone in 7 days in samples of soil from plat 350 (good soil) and from plats 330 and 340 (poor soil), Truckee-Carson Experiment Farm. state of preservation must have a very low ammonifying power. The medium described previously, consisting of 1.5 per cent peptone and inorganic salts, was inoculated with samples from plats 330, 340, and 350, and the ammonia produced determined at 10-day and 20-day incubation periods by distillation with magnesia.’ The results of this experiment are shown in figures 19 and 20. As the ammonification of the samples of poor soil, plats 330 and 340, was very similar, the results are averaged and shown as a single curve. The fact that there is no increase between the 7-day and 15-day periods indicates that the maximum had been reached before any 1 Dr. J. G. Lipman has recently suggested the use of dried blood as a source of nitrogen for work of this character. See Lipman, Jacob G., and Brown, Percy E., “Experiments on Ammonia and Nitrate Formation in Soils,’’ in Centralblatt fiir Bakteriologie, Parasitenkunde und Infektionskrankheiten, pt. 2, vol. 26, no. 20-24, April 9,1910, pp. 590-632. 211 8 DETAILED STUDY OF SOIL TYPICAL OF EXTENSIVE AREAS. 31 determinations were made. Yet these results show conclusively that in both good and poor soils there are large numbers of ammonifiers which are physiologically active if proper conditions are provided for them to develop. The relative differences in their ammonifying power and whether or not there are conditions in the soil to prevent’ their normal activities remain to be shown by further experiment. Denitrification is of two kinds: The reduction of nitrates to lower forms or transformation into organic form, and the complete breaking down of the nitrogenous substance with the evolution of free nitrogen as a gas. Either of these processes could be a source of infertility. DEPTH AT WHICH SAMPLES WERE TAKEN. 67012" 127018” 187024" FARTS PER SULL/ION OF NMTROGEN AS ALNIOM/A. Fic. 20,—Diagram showing the.ammonification of peptone in 15 days in samples of soil from plat 350 (good soil) and from plats 330 and 340 (poor soil), Truckee-Carson Experiment Farm. The evolution of free nitrogen was determined by measuring the nitrogen gas produced from peptone-nitrate solutions at intervals of 7 and 15 days. The results are rather erratic, as is shown in Table VEE TaBLeE VIII.—Denitrification by samples of soil from plats 330, 340, and 350, Truckee- Carson Experiment Farm. Denitrification. | Tue, | Gas formed in— “| Depth of | Character soil. of soil. 7 days. 15 days. : | Inches. Per cent. Per cent. | 330 0-6 30 35 Poor. | 6-12 i 10 12-18 2 5 18-24 | 2 5 340 0-6 35 40 Do. 6-12 40 40 12-18 | 20 | 25 18-24 | 30 40 | 350 06 | 2 7 Good 6-12 in| 3 12-18 ie | 5 18-24 | 2015 20 211 82 SOILS OF THE TRUCKEE-CARSON IRRIGATION PROJECT. Table IX shows the difference between the good and poor soils in regard to total numbers and distribution of bacteria. The difference in the floras is more strikingly brought out when we consider the difference in the colonies from the different soils. The plates from the 6-inch and 12-inch layers of plats 300 and 310, which show low numbers, chiefly contained peculiar colonies surrounded by a wine- colored diffusible pigment. The colony itself was but slightly colored and, surrounded as it was by this pigment, produced a very striking appearance on the plates. One plate from plat 310 was apparently a pure culture of this organism. Such a plate obtained from soil where the growth or flora is almost always rich and varied is very rare, and is the only unusual condition thus far encountered that seems to cor- relate consistently with the unusual conditions of infertility. This peculiar colony was never seen on soils from the fertile spots, and the fact that it was so predominately present in the infertile soils and in those strata in which the peculiar black layer occurred certainly in- dicates that further study should be made of this point. Microscopic examination of the colony showed that it was a micrococcus associated with a mold. Taste 1X.—Total number of bacteria present in 1-gram samples of soil from plats 300, 310, 820, 330, 340, and 350, Truckee-Carson Experiment Farm. No. of Depth of Number of Character | plat soil bacteria: fof sail. | j per gram. : | ] Inches | 300 0-6 458,400 | Poor. 6-12 45, 000 12-18 48, 900 18-24 178, 500 310 0-6 | 1,930,500 Do. 6-12 729, 000 12-18 15,900 18-24 409, 500 320 0-6 507, 000 Good. 6-12 351, 000 12-18 419, 000 18-24 429, 000 330 0-6 1,335,000 | Poor. 6-12 915, 000 12-18 840, 000 18-24 1,197,000 | 340 0-6 4,200,000 | Do. 6-12 525,000 | 12-18 4,620,000 | 18-24 3, 780, 000 350 0-6 672, 000 Good. | G=12) ives esee | 12-18 636,000 | 18-24 210,000 | | CONCLUSIONS. (1) Nitrifying, denitrifying, and ammonifying bacteria are well distributed and universally present in the soils of the Truckee-Carson Irrigation Project and become physiologically active if favorable con- ditions are provided for their development. 211 CONCLUSIONS. oe (2) The lack of proper decay and humification of organic matter in many of the unproductive soils is due either to unfavorable bacterial conditions brought about by certain physical and chemical conditions or to an unusual bacterial flora. (3) The nitrifying bacteria in the soils of Fallon, Nev., are active at greater depths than in eastern soils and also seem to be unusually virile in solutions, although the data on these points are not con- clusive. (4) In general, the conditions at Fallon, as in any arid region, favor nitrification, which frequently becomes intense; the conditions rarely favor denitrification. Lack of nitrification, therefore, will not be a limiting factor in crop production, nor is there evidence of overnitrifi- cation or injury from excessive quantities of nitrate. Humification studies are probably of paramount importance. 211 ENDER. Page Agar, beef, medium for development of bacteria.............--....-...--+--- 9, 24 Alkali, black. See Sodium carbonate. relation of chlorids and sulphates to nitrifying power. .......---...---- 21-22 AVM OMMTCATLON Genito OL term: -ca-sce.t = s-'/2.52 oc1c 2 cae ce ce cee cece ee ete T measurement of power of soil flora at Fallon, Nev.......-.-- 30, 31 methods of determination in soil studies at Fallon, Nev...-... 9, 30 Ammonium sulphate, use in soil studies at Fallon, Nev........-.-.--- 10, 12-22, 27, 29 Analysis, chemical, methods employed in soil studies at Fallon, Nev......-.- 10-11, 26-27, 30, 31 Bacteria, colonies peculiar to certain soils at Fallon, Nev..............--.---- 32 counts, methods used in soil studies at Fallon, Nev.......--.-. 9, 10, 26-27 nitrifying, comparative action in soil and in solution, at Fallon, Nev. 30 number and distribution, relation to character of soil, at Fallon, aes eee ee Se te eee ne ee Cr erat eet eee awe toe 24-25, 32 Black alkali. See Sodium carbonate. Brown, P. E., and Lipman, J. G., on methods and results of soil studies. ....- 9, 30 Calcium sulphate, effect upon soil samples at Fallon, Nev. .........-.-- 26, 27-28, 29 Chemical anaylsis. See Analysis, chemical. Chester, F. D., on the bacteriological analysis of soils...............----+--+-- 24 Clay, eoilnidal: affected by calcium sulphate and gypsum at Fallon, Ney.-72- 26 a@geurrence in soil samples‘at Fallon, Nev..../.....--.----=-------+--->-- 10 6 EDEL 2 EE COLE CIINS rR pt er Ray te eg ene Ie, a 32-33 Decomposition, organic, product peculiar to poor soil at Fallon, Nev ....-..-.... 26 Momminertion-caeHniwion. Ob term. f520 2.5... sooce- ws ees codecs a= s5e eee 7,31 methods of study employed at Ratlon Neve a ssseec se 11, 22-24, 31 Dipotassium phosphate, use in peptone solutions at Fallon, Nev.........---. 9 Dunham’s peptone solution. See Peptone, Dunham’s solution. teameronorl method Of preparation ..5. 2. 262..02s..5---- 2 sce eae ge see ee eee 10 Failyer, G. H., and Schreiner, Oswald, on analyses of soils..............----- 1] Fallon, Nev., locality of investigations in soil bacteriology... 7,8, 11, 18, 20, 24, 25, 33 Hitrmoncor sollvextracts, Wallon: Nev cn. 2. : o> ee eee eee 28 Nitrogen, free, relation to presence of bacteria at Fallon, Nev.............-..-- pa nitric, quantity originally present, in soil samples at Fallon; Nev.. 8, 12-20 symbiotic and nonsymbiotic fixation, definition ...................-- 7 determination, at Fallon, Nev. 11 Omelianski and Winogradsky, formula for fluid culture medium........-. 19, 27, 28 Peptone, ammonification in soil samples at Fallon, Nev...............--.----- 30, 31 Dunham’s solution, use in denitrification studies at Fallon, Nev..... LL 22 solutions, composition, used at Fallon, Nev............-...-..--.-- 9 Potassium chromate, use in determining chlorids at Fallon, Nev..........-.-... ll nitrate, ingredient of peptone solution used at Fallon, Nev......... ll Remy, Theodor, on bacteriological investigations ............---.....-.----- 9 Rogers, 8. J., and Scofield, C. 8., on description of Truckee-Carson Experi- ment Parm. 2.22622 ./24 sees sees eec set oe he eee oe.a ene ee 8 Schreiner, Oswald, and Failyer, G. H., on analyses of soils...........-.....-- ad Scofield, C. S., on description of Truckee-Carson Experiment Farm..........- 8 Silver nitrate, use in determination of chlorids at Fallon, Nev................- all sulphate, use for removal of chlorids at Fallon, Nev..........-...----. 11 Sodium carbonate, presence in soilsat Fallon, Nev............-...-.---- ee Pe chlorid, use in peptone solutions at Fallon, Nev..............---.----- 9 Soils, eastern and western, comparison of properties....-......------------ 12, 25, 33 methods of treatment of samples at Fallon, Nev........-. 8-11, 22, 26-27, 30, 31 nitrification at different depths at Fallon, Nev.........-.-.....--..--- 7, 12-20 outline of plan of investigations at Fallon, Nev...........-.-..-.---.-- 7-8 typical, detailed study at Fallon, Nev....-..--.2...--.:.-.42-====eeee 25-32 Sulphate of ammonia. See Ammonium sulphate. Syme, W. A., on method of estimating nitrates............--=-.-+--- see 11 Truckee-Carson Experiment Farm. See Fallon, Nev. Urea, use in removal of nitrites from nitrates at Fallon, Nev.........-.-.-...-- 11 Voorhees, E. B., and Lipman, J. G., on bacteriological investigations.......... 24 Winogradsky and Omelianski, formula for fluid culture medium.........-.. 19, 27, 28 211 QO Us DEPARTMENT OF AGRICULTURE, BUREAU OF PLANT INDUSTRY—BULLETIN NO. 212. B. T. GALLOWAY, Chief of Bureau. A STUDY OF FARM EQUIPMENT IN OHIO. BY L. W. ELLIS, Assistant in Farm Management, in Cooperation with the Department of Cooperation of the Ohio Agricultural Experiment Station. IssuED JUNE 2, 1911. WASHINGTON : GOVERNMENT PRINTING OFFICE. 1911, BUREAU OF PLANT INDUSTRY. Chief of Burcau, BEVERLY T. GALLOWAY. Assistant Chief of Bureau, WILLIAM A. TAYLOR. Editor, J. E. ROCKWELL. Chief Clerk, JAMES E. JONES. FARM MANAGEMENT. SCIENTIFIC STAFF. W. J. Spillman, Agriculturist in Charge. D. A. Brodie, David Griffiths, and C. B. Smith, A griculturists. Levi Chubbuck, A. D. McNair, G. E. Monroe, and Harry Thompson, Experts. : G. A. Billings, M. C. Burritt, J. S. Cates, J. S. Cotton, H. R. Cox, M. A. Crosby, D. H. Doane, L. G. Dodge, J. A. Drake, J. W. Froley, C. L. Goodrich, Byron Hunter, H. B. McClure, J. C. McDowell, H. A. Miller, W. A. Peck, A. G. Smith, E. H. Thomson, and B. Youngblood, Assistant Agriculturists. M. C. Bugby, E. L. Hayes, A. B. Ross, E. A. Stanford, and G. J. Street, Special Agenis. J. H. Arnold, C. M. Bennett, and H. H. Mowry, Assistants. 212 2 2 LETTER OF TRANSMITTAL. U. S. DEPARTMENT OF AGRICULTURE, Bureau oF Piant Inpustry, OFFICE OF THE CHIEF, Washington, D. C., February 1, 1911. Sie: I have the honor to transmit herewith and to recommend for publication as Bulletin No. 212 of the series of this Bureau the accom- panying manuscript, entitled ‘““A Study of Farm Equipment in Ohio,” prepared by Mr. L. W. Ellis, Assistant in the Office of Farm Management. This paper is based on a detailed study, made in cooperation with the Department of Cooperation of the Ohio Agricultural Experi- ment Station, of the equipment and the distribution of investment on a large number of Ohio farms. Few people realize the relation- ship of land, buildings, equipment, stock, machinery, cropping sys- tems, and working capital to successful farming. This paper points out these relationships as they were found to exist on farms of various types in Ohio, and is believed to be a valuable contribution to the science of farm management. Respectfully, Wn. A. TayLor, Acting Chief of Bureau. Hon. JAMEs WILson, Secretary of Agriculture. 212 3 u™ CONTENTS. [SPAR NTGUVEU TOTES fs Se ee BN, ce yb Bie ma dae le LRA re et ae en ae, BEEP MTOR’ ITO? 3. 22%. ar sual nas. do uae aad eacic ccee es ao oe nee een ke SO hraractenourarms Shida eases 2s 6, ea aeons 2k ase ha CELT INDE Se SS Rare Bye errors ees eran Re ee eee Pee EMERLODOCEGY. ceo ais ott 1a ec aan tate te N te ae ae ak ee ees Distribution of investments by enterprises......................-2-.---- PapmpeCHI OF LG AVEIACG TAIN 252 ..o ks esa eceeee ce cde snces sence esacesennces LPB LOS aA RS EA eae ie nee ce ee aoe Se PREP CO cae es ee ee a a ve sVibe'8) 0151 (6 5 Lope RS bores oo Panny ee eR are Cs CICS St, bar) eg ava eae Spueomecdedsin farm buildings. 0) ass. soee.ceed cee ees et) DiMerererAr mnt CAh is. Doane hoe ka iden eae gaiek Saeko ates AEMIC GATT a ofa s 2 oy So whi alae ae A < Se Alek: BOER oe = EGeAMOMEO 48 S94 xpos 3 ae SS 2 Socore pie Sats Se ath Su be see ai Me Pema UE gU ROTI irdeto ia ies Aa Sets Wipe IR eb ae ab nel LA ae ALD leg 8 SUES ES Ee Dea ye RES ae Oe et Re RS Shey Lee ee Pete OUATEOUS DUMIGIN PS ics. 22's: Sele ten ce tee eee ah ee Spacewmrts wa tarm buildings: oF 22225 02..yokes Pee 2 esd ose Ie Ret Pn Neha Ofc es Shad ey Ae ae ds ak Rae ck od TEE eh ea Dara eet CPS se Ne 2S Dent Ce Be nk sete Sea Permonny property on the average farm... - . 2022-22-22 Sass. he dese eenne Machinery etOOlsNetCeraa er: Artery cl. Cis Mees | eats Pope ears sey) ae Berea Manno) & Tari. pun ok ds tole Des ad ob bat aR a ok ads ae Breas Mimerin CQUipmentves 402 S222 ioe. oe He < oaceeAs age te ao ae SN MPMPRILE DPD ore NV en 2 SF a 8h ie Wee PUT Bia et dain yg Sd Paga. “I wJ IVIUSTEATIONS Page. Fie. 1. Map of Ohio, showing the location and the numbers of the farms referred to in the tables of this bulletin......................... 2-85. ee 9 2. Plan showing the drainage system on farm 10 in Putnam County, Ohio. 40 3. Diagram showing the acre cost of individual plows, harrows, culti- vators, corn. planters, and grain drills... .....---.<<5 s20ss=seeeeee 51 4, Diagram showing the annual cost of individual grain drills, manure spreaders, and Wagons... .---.2.c-s~ecccee ee oo == ee er 52 212 6 B. P. 1.—649. A STUDY OF FARM EQUIPMENT IN OHIO. INTRODUCTION. Successful farm management presupposes a proper relation between the various factors of production. The process of adjusting land, labor, and capital into harmonious relationship is consciously or unconsciously followed by all farmers. In the course of time the successful farmer reaches the point where productive area, live stock, cropping system, labor, equipment, and working capital are properly balanced and a profitable routine may be followed. Before that point is reached, however, many expensive mistakes are usually made, and perhaps none are more keenly felt than those arising from improper distribution of capital. The study of farm equipment was undertaken for the purpose of determining from the study of successful farms the proper rela- tionships that should exist between investments in land, improve- ments, live stock, machinery, and tools. This report presents the results of a study of equipment on a number of Ohio farms where conditions were unusually favorable for obtaining the desired information. The data and observations would undoubtedly have been more complete and satisfactory had a thor- ough analysis of the situation been possible in the light of later knowledge. They are here presented in order to illustrate by concrete example numerous problems that arise in this field of investigation. A portion of the data obtained in these investigations has already been published.' METHODS OF PROCEDURE. The work was done under the joint auspices of the Office of Farm Management and the Department of Cooperation of the Ohio Agri- cultural Experiment Station. During February and March, 1909, in connection with the annual inventories on the farms of about 35 statistical cooperators, a detailed study of the equipment was made in so far as it was possible to obtain information from the proprietor 1Cireular 44, Bureau of Plant Industiy, “Minor Articles of Farm Equipment.’’ This circular will be sent free on application to the Secretary of Agriculture, 84053°—Bul. 212—11——2 7 > 8 A STUDY OF FARM EQUIPMENT IN OHIO. ormanager. Specially prepared forms were used in order to embody full details. Previous surveys of the various farms by Mr. H. C. George, of the Ohio Agricultural Experiment Station, gave accurate data as to the size of each, the areas devoted to different purposes, the length and character of fences, and certain other details. Meas- urements and sketches were made of the buildings, and numerous details as to their character and condition were noted. The extent, character, and cost of water supply and drainage systems were studied. The usual inventory of live stock, machinery, tools, and supplies was made to include many details in addition to mere values. Messrs. Abbott, Bugby, Elser, and Lloyd, of the staff of the Ohio Agricultural Experiment Station, assisted at various times in the field work, and Mr. C. A. Massaro, of the station staff, assisted in the compilation of the data. Difficulty was encountered on every farm studied in obtaining all the details desired. Especially was this true in the matter of cost of permanent improvements, the installation of which usually ante- dated the tenure of the incumbent proprietor. The determination of the present value of real and personal property was also especially difficult, as a uniform basis could not be maintained for the recon- ciliation of exchange value with the value in use. Previous to the work just mentioned about 20 successful Ohio farms were visited by Mr. H. C. Thompson, of the Office of Farm Management, and less complete equipment studies made. Some data from this source are included in this report. A third source of data consists of circular letters dealing with corn and tillage machinery which were sent out in 1908 to a selected list of Ohio farmers. Over 100 carefully prepared reports of this character have been drawn upon for material. CHARACTER OF FARMS STUDIED. The farms from which data are embodied in this report are probably above the average type in the character of the proprietors, methods and equipment, yet they are not necessarily examples of exceptionally successful management. They are well scattered over the State, as shown in figure 1. Only those visited in 1909 were analyzed as to the chief enterprises conducted. For convenience, these farms have been numbered as in the various tables presented later. On 23 of these farms it was found possible to make a complete distribution of investment by enterprises, and this report has chiefly to deal with the farms so distinguished, but data from two of them are excluded from the averages here given because one was a small truck farm and the other a general farm on which special conditions had operated to 212 CHARACTER OF FARMS STUDIED. 9 reduce the equipment investment to an abnormally low figure. Fig- ures from both these farms, as well as from a number of farms on which the analysis could not be completed, are nevertheless made available for comparison. The 21 farms represented in the tables showing average distribu- tion of investment range in area from about 50 to 400 acres, the average being about 166 acres. In this and other particulars they differ materially from the State averages as reported in the Twelfth MICHIGAN —-—_. WAYNE HOLMES 18 J | iE HARRISON 23 re WEST VIRGINIA KENTUCKY Fic. 1.—Map of Ohio, showing the location and the numbers of the farms referred to in the tables of this bulletin. Census (1900). According to the census report 32.4 per cent of the farms of the State were between 50 and 100 acres in area, and 24.3 per cent were between 100 and 175 acres. Table I presents a compari- son of the average values for all farmsin the State, as shown by the census, with the average values for the 21 farms. It will be remem- bered, however, that the census valuations are made on the basis of sale values. In taking the inventories of the farms included in this investigation, consideration was given to both the sale value and the 212 1), Me A STUDY OF FARM EQUIPMENT IN OHIO. original cost of the property, less a reasonable depreciation charge based on its condition, the length of time already in use, and its expected total life. Contemplation of this difference of method will lessen the apparent difference between these farms and the average for the State. TABLE I.—Comparison of average values for all Ohio farms (census of 1900) with average values for a group of 21 farms of this investigation. For the State (average area | For 21 farms of this investiga- 88.5 acres; 78.5 per cent im- tion (average area 165.88 acres; proved). } 80.9 per cent improved).! Items of valuation. Per Per Per Per Per Per farm. acre. cent. farm. acre. cent. Total of land, improvements, live stock, andimachinery:...ts..se ne a= ce wee $4, 333 $48. 96 100.00 | $14,461.10 $87.17 100. 00 Of land, fences, drainage, water supply, CUE Senor Se pur cocicd Gone anHat en Saepe ee 2,953 33.37 68. 16 8, 748. 56 52. 72 60. 48 Ofbuildingss--222s- see eee ca eeee ee 793 8.96 18. 30 3,049. 47 18. 38 21.08 Of implements and machinery.......... 132 1.49 3. 04 773. 92 4. 67 5.36 ORNIVGSLOCK=.~.-s a2 on ssas ee ece= ses 8 455 5.14 10.50 1, 889. 15 11. 40 13.08 1In the average for the entire State the item of improved land includes all land regularly tilled or mowed, land pastured and cropped in rotation, land lying fallow, land in gardens, orchards, vineyards, or nurs- eries, and land occupied by buildings. No instructions were given to census enumerators as to the dis- sition of public and private roads, all or part of which may be included in the farm areas covered by eeds. In the average for the 21 farms, waste land, roads, and barn lots are classed together as nonpro- ductive. Pastures, tilled fields, and orchards constitute 80.9 per cent of the total area. (See Table II for details of acreage.) Of the 21 farms 6 include dairying as the principal enterprise, 1 is devoted largely to feeding sheep, and 2 others place greater emphasis on the feeding of cattle than the average farm, but in no instance are the equipment and management those of a highly specialized type of farm. They represent, on the whole, the most common type of farm to be found in the State. Concerning the farms visited by Mr. Thompson and those cov- ered by circular letter it may be said that they represent the general rather than any special type, and are probably better organized, equipped, and managed than the average of all farms in the State. It is the equipment of this class rather than that of highly special- ized farms or that of groups including both the best and poorest examples of farming that has been studied in the endeavor to estab- lish logical relationships between the land, improvements, stock, and machinery required for successful operation. The data here presented are conclusive only in so far as the farms studied are typical. It is held, however, that similar analyses of a large number of farms in any section would afford reliable averages from which the proper distribution of capital in equipment for a given farm could be predetermined with scientific accuracy. 212 DISTRIBUTION OF INVESTMENTS. 11 DISTRIBUTION OF INVESTMENTS. Three distinct objects are sought in this study of farm equipment: (1) The amount of equipment necessary and its first cost; (2) the inventory valuation at a given time; and (3) the equipment charge on farm operations, a portion of which is represented in the differ- ence between the first cost and a succeeding inventory valuation. The second phase will be discussed first; that is, the present distri- bution of investment as shown by the inventory. Land, buildings, fences, drainage, water supply, live stock, machinery and tools, and produce and supplies are regarded as the principal classes of equip- ment. These classes are also divided among the enterprises. The enterprise rather than the farm is regarded as the unit. LAND. Table II shows the distribution of acreage for 1909 by enterprises for the various farms. The term ‘‘General’’ includes areas in lots, lanes, waste spots, public roads, and all other lands belonging to the farm which can not properly be charged to one enterprise or to a group of enterprises. “‘Household” includes the dooryard, the family garden, and also the orchard where the growing of orchard fruits is not at all a commercial proposition. Tenant yard, garden, etc., are charged to ‘‘Labor.” ‘All stock” refers to all lots and fields devoted exclusively to live stock. Where pastured fields con- tain any considerable growth of trees, the judgment of the surveyor was relied upon for a division of the field into pasture and woodland. Temporary pastures are included under this head; hence, the areas devoted to “All stock” and “All crops” would vary from year to year. The term ‘All crops” includes all tilled and mowed fields. On several farms certain groves, considered as permanent, were maintained largely for the production of maple sugar or sirup, hence the occurrence of a “Sugar” enterprise. The term ‘‘Orchard”’ includes only fruit orchards largely commercial in their nature. “Woodland” comprises not only natural tracts but areas’ planted for the production of wood, posts, etc. The value given for the bare land represents as accurately as possible the value exclusive of all improvements. 212 12 A STUDY OF FARM EQUIPMENT IN OHIO, TaBLeE II.—-Acreages devoted to various enterprises on 23 farms and the value of the land minus all improvements, with the average and the percentage of the total for a group of 21 of these farms.! Value D i f G H All All O Wood te oa ignation o yen- ouse- y: r- ood - cent are : eral. | hold. |L®°r-| stock. | crops. | 5"8"-\chard. | land. | DOtal-| “in | and | crops.; per acre | Ve eses. Meuse 0.93 DSB iseteess 56.48}. Sbs86 ji cboscdececs ce 22.10 | 116.20] 30.8 | $61.62 PE et eee 3.86 AS SY) eee DE5425) (GRAN eee ee 35.36 | 164.11 | 41.5] 19.53 8 ee oe Aer ee 3. 68 166) ites 2c 2 16. 97 iss Hy ¢ il aS ae 14. 43 | 13.80 | 104. 25 51.5 | 41.44 eae ene. Ae oe 4.38 1S eee 25,96), 56:22) | 165355]! “4:07 2202225 108.34 | 51.8} 31.15 rR eee eS 4.28 SEY | sees 37.50 43:60.) 2oreds| os, oko 1.05 | 143.32 51.4] 24.18 f(a ae ed Ge 4.07 1A eee 18598 "]), 320580 22. oscar 4.07 | 49.61 | 42.0] 33.00 Beas os Seen 2.94 203 ae = 5 14. 52 OSD! cas eee nce 1.00 78. 64 74.0 | 87.74 DOSS . ocese coe 5. 41 102) O885.)) Sk S5cl - ea506h = ae cele eo 26.00 | 147.67 | 56.1 |, 65.99 SOE b..- 2 stee2252> 5.44 G304 [et escu 5:00" S410 Soe a sok. 3 4.03 | 100.00 | 84.2} 71.00 i eee eras 1.83 7) (eee 28.3%. 104: GO Ike. hae ae 20.00 | 156.97 | 66.7 | 650.14 See ce Se ee a 4.93 SOs | Seceea } oosOa') S40) JONES: >. cc) sence 15.91 | 198.25} 71.0] 406.55 1 Ve Se ere 8.98 Ber (| = eerste 122; 60! (19700 bee Se Aco 56. 67 | 388.92 | 50.7} 60.00 Ox eeees soe See Sc 4.83 ay, (eee uel yy Fie Me 2h Sy ee | 15.13 | 219.82 | 58.6] 43.90 | | ee Se ae 3.35 cE PA Ce 1 Be Sl Be a ee ee ee 39.29 | 172.52 | 67.5] 45.97 NiPeseeceeeseccse 10. 38 2.65 AQ | 584.93)) 12247 123.05 |52c. 2-2 30.02 | 275.99 | 45.1] 64.89 PSS ere Me esec cose s 8. 40 fe GW ee Sore 26.02) 123.20 eon sans 3.71 | 44.75 | 207.83 | 59.4] 56.49 19 See os eee 3.00 7 «a eee 21.81 Ce ON ee ee ee 7.93 | 103.81 66.8 | 40.17 ie Ae 7.18 «DO oem == S430" (84.56 2-22 ee .99 | 7.7L | 185.25°] 45:7) 43.97 PANES = eae aac 14.11 1.47 73 62. 44 68. 58) |--> S22 4.7 76. 50 | 228.62} 30.0] 22.26 DE era a dt he 3.33 i he! YM ey. elas LOS S40 SI |e oe 2.44 | 13.76 | 156.00 | 19.9] 25.55 D8 Be eet ae es eee 10. 31 Bespin oe O266 i Wisse ae eS 10.49 | 8.15] 177.27] 43.5] 29.59 FY: Wg Se Ne Sone Sag teal oa 3.85 gs" el ee ee BIJ00 | OP 23. Poe teens el 23.04 | 148.38 | 48.2] 19.61 Dinas. SRA Le Ae . 65 2 (eee Py nee i eed DOS | Seve 10.85 | 91.9} 40.10 For the group of 21 farms:! \(mean)| (mean) Average.....- 5.51 2.04 .08 46. 50 85.71 2.98 1.95 | 21.11 | 165.88 52.8 | 45.96 Per cent of to- tal acreage. - 3.32 1.23 -05 | 28.01] 51.68} 1.80} 1.18 | 12.73] 100.00 |---.---|.---_.. 1 Nos. 5 and 11 omitted; Nos. 24 and 25 not included in average. An examination of the table shows that the mean average acre valuation of bare land for 21 farms is $45.96. For farm 1 the acre valuation of bare land is $61.62. For farm 2 it is $19.53. These are both dairy farms in the northeastern part of the State. Farm 1 is 14 miles from town, on a stone pike, while farm 2 is 5 miles out, on a dirt road. Part of the woodland of farm 1, but no distinct area, produces maple sirup in commercial quantities. Farm 4, with an acre valuation of $31.15, and farms 8, 9, and 10, with acre valuations of $87.74, $65.99, and $71, respectively, are all level farms. No. 4 needs considerable drainage. Nos. 8, 9, and 10 are well equipped with tile drains. Nos. 8 and 10 show high percentages (74 and 84.2, respectively) of land in crops, as compared with the mean average of 52.8 per cent for the 21 farms. Farm 25, with 91.9 per cent of land in tilled crops, and situated within a stone’s throw of an inter- urban railway, shows a bare-land valuation of $40.10 per acre. This farm, however, lacks tile drainage and is overequipped with buildings as compared with other farms. (See Table III for data on building equipment.) Farm 3, with an acre valuation of $41.44, has a very expensive building equipment, and even when the latter is placed at a very low figure compared with its cost it leaves a low 212 DISTRIBUTION OF INVESTMENTS. ee figure for bare land. Farm 14, although the largest of all, with a total of 388.92 acres, has but 50.7 per cent of the land in crops. It contains, however, a large acreage of productive bottom land, has a low building investment per acre, and has good roads to a shipping point, so that the bare land has an acre valuation of $60 as compared with the average of $45.96 for the 21 farms. Farms 20, 21, 22, and 23, with bare-land valuations of $43.97, $22.26, $25.55, and $29.59, respectively, are all located in the hill section (southeastern part) of the State. No. 20 (valuation $43.97) shows an unusually low area in waste and timber land for a hill farm and is connected with town by 6 miles of pike road. No. 23 (valuation $29.59), with nearly the same area, distribution of acreage, and distance from railway station, is separated by 3 miles of hilly dirt road from the pike leading to town. No. 21 (valuation $22.26) has considerable waste and timber land; and No. 22 (valuation $25.55) has been wisely kept in pasture for the greater part, though a greater area in crops would have made it more attractive to a buyer. Farms 12 to 17, inclusive, range in bare-land value from $43.90 for No. 15 to $64.89 for No. 17 and are located in the large-farm area of central and southwestern Ohio. Only one of this group falls below the average bare-land valuation of $45.96. These farms are well equipped with buildings and are easily reached by pike roads from good towns. Most of them show a higher percentage of crop land than the mean of the whole number and are in a high state of productivity. Farm 24, with a bare-land valuation of $19.61, is located in a rougher section in southern Ohio, is underequipped in buildings, and is conservatively valued rather than otherwise. From these examples the land values due to good roads, good drainage, high percentage of crop areas, good topography, and adequate improvements can be plainly seen. PERMANENT IMPROVEMENTS. The appraisement of the true value of permanent improvements in this study was extremely difficult and the values given must be accepted with due allowances. Wherever practicable the basis for fixing values should be that expressed in the following question: ‘‘What is the value of this item as a part of the equipment of this farm, remembering that the sum of these values must equal the value set upon the farm as a whole?” Land values have increased in nearly every section, unfortunately not through improvement of the land by farming, but through an advance in the value of land as a raw material. We have no means of determining the present pro- ducing power of a given farm as compared with that at the outset, nor what its rate of appreciation or depreciation has been in this 212 14 A STUDY OF FARM EQUIPMENT IN OHIO. respect. It seems well established that where no systematic steps have been taken to prevent it or to repair damage there has been a steady depreciation in the productiveness of these farms. The buildings and other improvements on any farm may clearly have undergone a process of deterioration, yet the sale value of the farm may have been enhanced, not only by the rise in land values, but also by increase in value of the raw materials from which improve- ments are constructed. Well-planned improvements may add value to the farm above their cost of installation, while others may im- mediately represent the loss of a large part of their cost, if measured by their effect on the farm value. Each farm, therefore, was studied as an individual problem and is most interesting when considered in that light. DRAINAGE. Tile drains are so intimately associated with the land that it may be impracticable to consider them separately. With the possible exception of the cost of water supply, the outlay in tile drainage is only one which can be depended on to add its face value or more to the value of the bare land and continue to do so indefinitely. The drains occasionally become clogged and require cleaning, but in this study they have been appraised at the full cost of installation. ‘To attempt to appraise them accurately on the basis of their effect on the farm value would be impossible from the information at hand. No valuation has been placed on natural drainage channels con- sidered aside from the land. The investment in artificial drainage systems has been attributed directly to che portions of the farm drained. WATER SUPPLY. On-many Ohio farms there are natural sources of water supply, which, like natural drainage, can scarcely be valued apart from the land. Their value may not equal their cost, as in the case of streams which permanently render a considerable area unavailable for crop- ping or which subject fields and fences to damage from high water. On the other hand, the value of a continuous supply of pure water in a convenient place, without expense or labor, can not be estimated by comparing it with the cost of installing artificial water systems, which may represent several failures before a satisfactory supply is obtained and will surely represent a continual expense for labor and maintenance. In studying the distribution of the investment, only the cost of installing the water system has been considered, less a fair amount for depreciation of pumps, tanks, windmills, etc. This total investment in water system has been divided as accurately as possible among the various enterprises on the basis of use. This naturally 212 DISTRIBUTION OF INVESTMENTS. 15 places the heaviest charges on the household and those classes of live stock which do not have access to natural supplies in the fields. FENCES. Fences well planned and constructed undoubtedly add at first more than their cost to the value of farms, yet, if not well located, they may prove a handicap to the most profitable cropping systems. They are subject to rapid deterioration, involving considerable attention and expense; hence, overequipment in fences may tend to reduce land values. Certain phases of the fence question were studied in detail and will be discussed later, but in ascertaining the investment in fences the first cost and the condition at the date of inventory were the only points considered. The cost of construction was difficult to obtain, owing to the fact that practically all fences are built by farm labor, and standard costs per rod have not been established, as has been done, for instance, for the digging of ditches for tile drains, which is often paid for on a unit basis. The price of posts varies widely in different localities and has generally advanced since the building of the older fences. The value of fences, therefore, was based largely on the cost of replacing them, less a fair percentage for depreciation. Worm rail fences constitute a large proportion of the total on many Ohio farms. When built, the value of the material was practically disregarded and labor costs were very low as compared with the present rates. It would be impossible to replace these fences except at a prohibitive cost, yet their real value to the farm is no more than that of modern fences. Many are in an excellent state of preservation, yet occupy enough additional ground to offset any advantages they may have over wire fences. Asan expedient they have been valued at a figure approximating the labor cost of building. All fences were charged to ‘‘General enterprises,’’ only the farm’s share of division fences being included. BUILDINGS. Many buildings found on the farms studied are from 40 to 75 years old and of a type of construction not commonly used at present, the frames being composed of large, hewn timbers. Much of the other material has been cut and sawed on the farm, the value of the timber at that time being very low as compared with present prices. These buildings, as a rule, are still in such condition as to be capable of long service without excessive repairs. The first cost of material and labor was low, yet on the present basis it would be almost out of the question to duplicate the buildings. It follows, then, that neither the cost of building nor the cost of replacing these structures can be relied upon absolutely in appraising 84053°—Bul. 212—11——3 16 A STUDY OF FARM EQUIPMENT IN OHIO. their value. As previously stated, the cost of the more modern buildings is not a true indication of their value to the farm, but insur- ance figures are quite largely based on their condition and the cost of replacing them. A comparison of the sale values of land without buildings and land with buildings, all in the same neighborhood and of equal productiveness, shows that the difference in favor of the buildings is almost without exception greatly insufficient to equip the unimproved land with those structures which are absolutely neces- sary to the conduct of an independent farming enterprise. The real value of farm buildings as a part of the total investment is therefore very difficult to ascertain, and depends largely on the point of view. In this study the building values are a compromise between the cost of equipping the farm with similar structures, less a proper amount for depreciation, and the sale value of the buildings as sug- gested by comparing the values of land with and without buildings. The value shown for the bare land, therefore, is reduced somewhat by this method, possibly as much as it was increased by the method of appraising the fence, drainage, and water-supply systems. It can safely be said that buildings represent not only the most expensive class of farm equipment, but the least negotiable. Leav- ing out household buildings, the remainder on the farms studied shows a much greater variation in investment per acre than any other class of equipment, and a greater variation in percentage of the total investment than land, water supply, live stock, or machinery. Fences, artificial drainage, and water systems may often be dis- pensed with wholly or to a great extent; hence they are scarcely comparable with land, buildings, live stock, and machinery as regards the relative investment. One of the most important phases of a study of farm equipment is the determining of the relation that should exist between buildings and the farm enterprises, in order to reduce the wide variation in investment per acre in buildings designed for the same purposes. Prior to a study of the cost and construction of buildings there should be established standard space units to be used in determining the actual building requirements of the farm for the storage of products and machinery, the housing of live stock, and the transaction of the farm affairs. In this study buildings were investigated from that standpoint, but insufficient data were gathered to allow of generali- zations. For purposes outside of this study it became desirable to make a division of building investment by enterprises. As the floor and cubic space devoted to each enterprise had been calculated for the various buildings, a division on the basis of cubic space was worked out and is presented later in tables and discussions. 212 - DISTRIBUTION OF INVESTMENTS. 17 Tt will be at once apparent that a division of space on the basis of cubic feet devoted to various enterprises in barns, for instance, is open to serious criticism. This subjects such products as hay, straw, etc., stored in mows, to greater building charges than horses and cattle, for which greater expense is incurred in constructing stalls, mangers, floors, etc. In order to correct this error additional study of the cost of construction of the various portions of the buildings would be necessary, and the need for this did not occur in time to include it in the scope of this study. Factors for the relative cost of various portions of farm buildings of ordinary construction could no doubt be worked out, by means of which the cubic space devoted to any enterprise could be made the basis for an, equitable division of the total value. Some method is desirable, as it is incorrect to charge live-stock enterprises with the investment in portions of the buildings devoted to other enterprises. Animals may be fed grain in a barn for a short time each day and pastured outside, while both hay and grain may be stored in the barn continuously for market. A storage charge, in the latter case, should unquestionably be added to the cost of production. It is only logical to base the unit charge on the amount of the commodities stored, taken in connection with the total annual cost of that part of the building designed exclusively for storing products. A unit-storage charge based on cubic space would place on the proper classes of live stock the burden of the large amount of storage space required for roughage. A division of the entire building charge on the basis of the number of 1,000 pounds head of stock sheltered, or on the floor space occupied, might be unjust to the hog enterprise, for which a comparatively small space is required for storage of feed. ete, = el { $8.82 |$12.91 52.11 | $0.39 | $0. 43 \s10. 89 | $5.74 | $1.90 6.09 | 4.88 1.52 52 -37 | 10.06] 3.80] 3.17 26.85 | 23.98 4.37 2. 40 -96 | 13.08 | 6.37 6. 45 12.96 | 6.46 2.96 -28 1.57 | 12.33 6.30 | 3.04 6.29 | 6.29 3. 9 Pree 1.19 } 12.32 7.58 | 2.26 8.87 | 6.25 4.50} 1.21 1.61 | 19.35 | 12.70 | 2.65 12.70 | 23.90 5.08 | 13.98 | 3.17 | 8.31 6.94 | 4.48 10.08 | 13.93 -64 | 3.38 .74 | 12.20 | 8.56] 8.80 12.15 | 15.25 5.90 | 17.7 3.00 | 14.97 | 6.45 | 2.75 24.40 | 11.46 2.52 | 11.66 1.75 | 16.02 | 5.03 4.17 11.35 | 14.38 5.69 | 3.43 Meee ebeesO) ||) 4095 7.01 4.43 4.07 2.29 89 -40 | 10.11 2.87 | 3.80 4.23 4.09 3. 65 61 sor || 8.99) (3.09!) 2577 4.7 4.17 BUGZ Nes as I -58 | 7.46 | 3.94] 3.06 4.44 | 10.51 3.88 79 -49 | 12.50 |} 3.71 1.00 1537 8. 86 1.52 1. 66 72 9.24] 5.02 | 4.85 22. 81 9.81 3.86 | 2.89 - 68 | 24.58 7.05 | 8.93 12.07 | 6.20 3.06) [So ea ek -27 | 15.57 | 3.00) 4.41 3.16 | 7.55 3300) |e eeeee 2.40 | 5.95) 3.54 1. 64 6.79 | 9.62 2s |e oe -44| 8.21 2.22 1.83 3.27 | 8.86 ASOGH Stee se 1.60 | 10.01 3.85 4.54 For the group of 21 farms: 1! Mean (farm unit)..... ...| 165.88 | 45.96 | 10.59 | 10.16 3.39 | 2.94 P18 |) 22:12") 5336] 3.97 Average (acreage unit)-..| 165.88 | 46.25 | 9.27! 9.11 3.22 | 2.21; 1.04] 11.40] 4.67] 3.81 For the entire State: Average (census of 1900)..| 88.50 | 33.37 | 8.96 |_......|......--]...-..-|....-.- OAM ed AO) aes | Possosessseessedescaeesescess 342.00 | 27.98 | 18.29 | 17.87 3.66 | 8.17 2.04 | 10.38 | 3.14 5. 68 eee Pas 2 eb By eo 186.71 | 80.34 | 8.17 | 6.56 Bes eh Baten 1.55 | 15.76 | 7.04) 6.44 PL 3 a a ae 148. 38 | 19.61 67 | 5.39 16842 nee 14 5.78 D7, .78 2S tah SOO CE- ~ CPOE Pee 10. 85 | 40.10 | 32.25 | 46.09 y PL eee 1.84 | 21.95 | 14.39 - 93 ener Seis sone deateceece lesae TSBs SO NNGOSOUU [Em ee sine aa owt eee ee 7.53 | 4.51] 1.38 24 (eS CO CE ROOD EE EOC 1805005 169! 98h 5 SOLON 16H ses eel an cee Pee. 11.95 | 3.60] 2.45 13's nr SOE Ae Oe te eee ee 504.00 | 70.00 | 17.11 CSSA (ge ty (a ee | es ee 24.12 | 7.56 | 4.73 Pe Pe iss 5 seat oskhecoue s LOGS ODN T6292" leis 20M LDS Sep leoe wee oc ad Sos occ 9.30 | 7.19 4, 02 FT A a ee a 79.00 | 48.04 | 6.33 | 31.64 ie ee 1.14 | 18.20 | 6.13 | 2.84 1 Nos. 5 and 11 omitted. 20 A STUDY OF FARM EQUIPMENT IN OHIO. A close study of Table IV will reveal striking differences in the investment per acre for different purposes. As a basis for com- paring the individual farms the mean and the average of the data from 21 farms are both included. The mean is obtained by adding together the figures per acre for the 21 farms and dividing by 21, while the average is computed by taking the total investment for the 21 farms and dividing by the sum of their acreages. The mean, then, is an average having the farm as a unit, while the average regards the acre as the unit. These two might vary widely, and the fact that they do not adds to the value of the table. In this study of farms the mean is regarded as the more suggestive, since it takes into account the effect of the size of the farm upon the acre invest- ment. The range of investment per acre in farm buildings is seen to be from 67 cents on farm 24, where a very old barn and several equally old sheds, ete., constituted the building equipment, to $32.25 for farm 25, where the value of a small barn and poultry house is divided by a small acreage. The investment varies with the condition and number of buildings, but the number and cost do not vary with the acreage. Farms 13 to 17 are similar in character and location, yet the building equipment on farm 13 is $11.35 per acre, while on Nos. 14 to 17, inclusive, the valuation does not reach $5 per acre on any farm. This is due to the fact that farm 13 is really composed of three farms formerly separate. On the other hand, farms 3, 5, 12, 18, 19, and 28, ranging in size from 104 to 504 acres, show an invest- ment in farm buildings of $15.78 to $26.85 per acre, while farms 7, 8, 10, and 30, varying in size from 49.61 to 100 acres, have an invest- ment in farm buildings of but $6.33 to $12.70 per acre. In household buildings (dwellings) there is a variation from $4.07 to $46.09 per acre. The 21 farms as a whole have practically the same investment in farm buildings and in household buildings ($10.59 and $10.16, respectively), but among the 30 farms wide extremes are represented. Farms 4, 12, 18, 19, 20, and 28 show two to three times as great an acre investment ($12.07 to $24.40) in farm buildings as in household buildings ($6.20 to $11.46), while on farms 8, 21, 23, 24, 29, and 30 the investment in household buildings ($5.39 to $31.64) is two to five times as great as in farm buildings ($3.16 to $12.70 per acre). No particular need is apparent for such a wide variation in prac- tice, and on a number of the most successful farms the investment in household and farm buildings is about equal. On farm 24, with a farm-building investment of $0.67 per acre and a household-build- ing investment of $5.39 per acre, a new barn was to be erected within a year or two which would bring about nearly the same relative 212 DISTRIBUTION OF INVESTMENTS. 21 condition as exists on farm 18, on which a $3,000 barn had just been completed and on which the farm and household building invest- ments were $15.78 and $8.86 per acre, respectively. The owner of farm 30 moved from the city only a few years ago and invested the greater part of his ready capital in remodeling the dwelling. His percentage of total investment represented by the household building is much higher than that of any other farm except No. 25, the small- truck and poultry farm, and slightly exceeds even that. This owner noted the lack of certain essential machinery, which lack was directly due to the excessive outlay in household buildings and conveniences. New buildings for either household or farm use tend, of course, to vary the relation, as does also the presence of tenant houses, which are classed with household buildings, yet the few farms studied would indicate that the investment in buildings for the two purposes should be approximately equal for farms of the general class. A large part of farm 9, with an investment for fencing of only 64 cents per acre, is unfenced, and on several others a large extent of rail fence accounts for a low investment per acre. Attention is called to farms 7 and 8, with fencing investments of $4.50 and $5.08 per acre, respectively, on which the proportion of road fence is particu- larly large. Farm 13 has considerable road fence, but the high investment ($5.69 per acre) is largely due to the recent construction of woven-wire fences and the generally good condition of those pre- viously installed. The acre investment in tile drainage and water supply depends largely on the natural advantages of the farm. The extremes are, for drainage, 28 cents on farm 4 and $17.70 on farm 10, the average being $2.21. The extremes for water supply are 37 cents on farm 2 and $3.17 on farm 8, with an average of $1.04 for the 21 farms. Farms 8 and 10 have a high investment in all improvements and are the two highest in the valuation of tile drainage, $13.98 and $17.70 per acre, respectively, yet they show the highest bare-land values, $87.74 and $71 per acre, respectively. Both are connected with town by good stone roads, but the thorough drainage undoubtedly is a large factor in maintaining the value of the land. The small acreage of farms 7 and 25 (49.61 and 10.85, respectively) makes the acre investment in water systems large, even though the systems are not extensive. Farms 8, 21, and 23, with an acre valu- ation for water supply of $3.17, $2.40, and $1.60, respectively, have more or less extensive water conveniences in the dwellings. Farms 21 and 23, with investments of $2.40 and $1.60 per acre, respectively, for water, are to be contrasted with farms 18, 19, 20, and 22, with the respective valuations of 72, 68, 27, and 44 cents. These four farms are also in what is known as the hill section; hence, water might easily be obtained from springs. but the water conveniences have 212 22 A STUDY OF FARM EQUIPMENT IN OHIO. not been extended to the dwellings. Gasoline engines used only for pumping add to the investments on farms 10, 12, and 13, with the acre valuation for water supply of $3, $1.75, and $1.77 per acre, respectively. The live-stock inventory, like that of produce, supplies, etce., should be taken on the same date for all farms in order to be com- parable. This fact is brought out strikingly by farm 12. The inven- tory in 1908 showed $1,700 worth of steers on hand, or nearly $11 per acre for this class of stock alone. Several days previous to the 1909 inventory 39 head were sold, hence this farm, which is usually heavily stocked with cattle, shows a lower acre investment ($16.02) than its average for the year. The inventory of live stock, even if taken on the same date each year for all farms, would not show the average investment accurately, as on some farms feeding stock are purchased, fed, and marketed between succeeding dates of inventory. This would entail the investment of a considerable amount of capital for the greater part of the year which would not be apparent in a study of inventories. The study of investment in live stock can best be made in connection with Table VIII (p. 27) which shows the relative importance of the various live-stock enterprises. With the exception of 4 farms the acre investment in machinery, wagons, harness, tools, etc., ranges within comparatively narrow limits (from $2.87 for farm 13 to $7.56 for farm 28.) The four excep- tions are farm 22 (acre valuation $2.22), for which much of the machinery was borrowed; farm 24 (acre valuation $1.17), for which machinery was generally bought second hand; and farms 7 and 25 (valuations $12.70 and $14.39), which are low in acreage. With the exception of farms 22, 24, 25, and 28, the total machinery investment per farm is seen by reference to Table III to vary only about 136 per cent, as compared, for instance, to 1,275 per cent for the total value of farm buildings and 835 per cent for household buildings. Two large farms (5 and 14) containing 342 and 388.92 acres, respectively, show low acre investments in machinery ($3.14 and $2.87, respectively), while farm 28, the largest, containing 504 acres, ranks among the highest, showing an acre investment of $7.56 and indicating overequipment. The total and percentage of investment per acre in real and per- sonal property is given in Table V, together with the mean and average for the group of 21 farms. The odd cents shown in the values of the real estate are due to the fractional parts of an acre in the farm areas, these usually being disregarded by the farm owners. The land with improvements is seen to range from $27.48 to $146.57 per acre, though nearly all farms are valued considerably higher than the State average as shown by the Twelfth Census, viz, $42.33 per acre. The amount of personal property per acre, $7.73 212 DISTRIBUTION OF INVESTMENTS. ss to $40.65, is higher than the State average, $6.63, in every case. It is to be remembered, however, that for comparison the value of produce, etc., is to be deducted from that of the personal property shown, the census values including only live stock and machinery. Excluding produce, etc., the average of the 21 farms shows 81.4 per cent of the total farm value in real estate and 18.6 per cent in per- sonal property, as compared with 86.5 per cent and 13.5 per cent, respectively, for the State. The greater value of personal property on these farms argues the correctness of the statement previously made that the farms under consideration are more successful than the average. Including produce, etc., a mean of the 30 farms shows 77.34 per cent of the total inventory value to be due to land and improve- ments. The mean of the 21 shows 77.6 per cent in real estate and the average 78.14 per cent. Seventeen out of 30 farms range between 77 per cent and 83 per cent in real estate, these having a mean of 79.8 per cent. These figures should serve as an indication of approxi- mately the proper division of equipment capital on farms of this class, the cash and other assets of course not being considered in this study. TaBLEe V.— Total investment and percentage of investment per acre in real estate and per- sonal property for each of 30 Olio farms, with the mean and average for a group of 21 of these farms. Real estate. Personal property. | Total - 5 Area invest- Designation of farms. (acres). | Total | poy cent.|_ Total | per cent, | ment per per acre. *| per acre. “| acre. Le shat Ae ineeae ee See a 116. 20 $86. 28 82.30 $18. 50 17.70 $104. 81 ee ee a cee SR I I he cae 164. 11 32.91 65. 90 17.03 34. 10 49.94 Bho baekha cee) eC ah ee ee 104. 25 100. 00 79. 40 25.90 20. 60 125.90 A ea a - etee S oc Sets e te webs cas OSs 108. 34 55. 38 71. 80 21. 67 28. 20 77.05 tie 32.6 SRO ORE ORO EO a eee 148. 32 41.88 65. 70 22.16 34. 60 64. 04 eneee ose Bed ae Sabo ARE TS TECH ee ree 49.61 55. 44 61. 50 34. 70 38. 50 90. 14 78. 64 146. 57 88. 10 19. 73 11.90 166. 30 147. 67 94. 76 76. 20 29. 56 23. 80 124.32 100. 00 125. 00 83.70 24.17 16. 30 149.17 156. 97 101.93 80. 20 25. 22 19. 80 127.15 198. 25 83.17 77. 40 24. 26 22. 60 107. 43 388. 92 72.09 81.10 16.78 18.90 88. 87 219. 82 57.05 79.40 14. 85 20. 60 71.90 172. 52 59. 12 80. 30 14. 46 19. 70 73. 58 275. 99 85. 00 83. 30 if/APAl 16.70 102. 21 207. 83 85. 03 81.60 19, 11 18. 40 104. 14 103. 81 80. 22 66. 40 40. 65 33. 60 120.78 185. 25 66. 07 74. 20 22.98 25. 80 89.05 228. 62 38. 43 77. 50 11.13 22. 50 49.56 156. 00 44.75 78. 50 12. 26 21. 50 57.01 177. 27 47.38 72.00 18. 40 28.00 65.78 For the group of 21 farms: ! eed Gann NIG) oes cee oceeeeoecen's 165. 88 74. 22 77.60 21. 45 22. 40 95. 67 Average (acreage unit)................- 165. 88 72.10 78.14 18. 88 21.86 90. 98 For the entire State: Average (census of 1900).......-...---. 88. 50 42.33 86. 50 6. 63 13. 50 | 48.96 Fiede ned soc Cente eee GREE Soe ee reese 342. 00 78.01 80. 30 19.17 19. 70 97.19 HNP ae ne HAE Seis Sala Sate coeds pads 186. 71 100. 00 77. 40 29. 24 22.60 129. 24 me Pe aa ct osha eect iS alee Sialcie 2s EIS 148. 38 27.48 78.00 1.0 22.00 35. 21 ns i ee RECO Soe Eee EE aCe ee 10. 85 124. 43 77.00 37.27 23.00 161.70 2 pO GIO RUC ILE GALE ete Ee ee ieee: 156. 86 65. 00 82.90 13. 42 17.10 78. 42 eet eet oti actaan Ashen a cre ieladdetwea nin dpeiale ¢ 180. 00 90. 00 83. 30 18. 00 16.70 108. 00 BO, ae oI ae ain ey ee te 504. 00 93. 66 72.00 36. 41 28. 00 130. 07 ones See oa ooh ts saidudes Soh nce tea ae ae 156. 00 100. 00 83.00 20. 51 17.00 120. 51 Ss A ae \. en eee eee Se eee te 79.00 88.61 80. 00 PPA 20. 00 110. 78 1 Nos. 5 and 11 omitted, 84053°—Bul, 212—11—4 94 A STUDY OF FARM EQUIPMENT IN OHIO. The percentage of the total investment represented by each class of equipment is given in Table VI. The uniformity in the percentage of value in land on farms 14 to 17 ($67.52, $61.10, $62.46, and $63.49, respectively) and farms 20 to 23 ($49.36, $44.90, $44.80, and $45, respectively) is interesting. The former are large level farms in the southwestern quarter of the State and the latter are large hill farms in the southeastern quarter. The influence of size of farm is to be seen in farms 7 and 25, and of large building equipment on several others already noted. TasLe VI.—Percentage of the total investment represented by each class of equipment on 80 Ohio farms, with the mean and the average for a group of 21 of these farms. Buildings. Ma. Pro- Peaslelh Water | 7; in. | duce Designation of Area Drain ~ | Live | chin- iH farms. (acres). tent: Tose: Benes age. nA stock. | ery, pike Farm. | hold. ete. tee 8.42 | 12.31 2.01 0.37) 0.41} 10.39] 5.48 1.82 12.20 9.74 3.05 1.04 -73 | 20.16 7.62 6.35 21.35 | 19.05 3.46 1.91 -76 | 10.39 5.06 5.12 16. 64 8.29 3. 84 36 | 2.04} 16.01 8.17 3.94 9.78 | 9.7 (Bs |lseoeseae 1.85 | 19.25] 11.82 3.51 9.85 6.93 4.99 1.34 1.79 | 21.46 | 14.10 2.94 7.64 | 14.36 3.05 8.39 1.90 5.00 4.17 2.77 8.11} 11.21 52 2.72 -60 9. 82 6.89 7.07 8.15 10.23 3.95 | 11.87 2.01 | 10.03 4.32 1.84 19.18 9.02 1.98 9.18 1.38 | 12.60 3.96 3.28 10.55 13.39 5.30 3.20 1.64 | 11.44 4.60 6.53 4.97 4.58 2.58 1.00 -45 | 11.40 3.22 4.28 5.89 5.70 5.06 80 -79 | 12.50 4.30 3.86 6.50 5. 67 EBUE) || eeos55- aon LOZ 5.35 4.16 4.34] 10.29] 3.80 78 -48 | 12.23] 3.62 -97 15.14 8.51 1. 46 1.59 -69 | 8.86] 4.84 4.67 18. 90 8.10 3.20 2.40 -60 | 20.30 5.90 7.40 13.55 6.97 ASO0N>-eaeeee .30 | 17.48 | 3.37 4.97 6.38 | 15.22 6.20 tecseoe. 4.90 | 12.00) 7.10 3.30 11.91 | 16.89 Be 0) ese 80 | 14.40 3.90 3.20 4.97 | 13.46 6: 18) {oo ccsene 2.42) 15.21 5. 86 6.90 Hot group of 21 Mean (farm unit)} 165.88 | 48.04] 11.08] 10.61 3.54 3.07 1.23 | 12.68 5.60 4.15 Average (acre- age unit). -.-.- 165.88 | 50.82 | 10.20] 10.01 3.54 2. 43 1.14] 12.54 5.13 4,19 For the entire State: Average (census 1900) sece----27 8850! |) 168-484)" LBSS6e|E--Se Sel eeen 3..025|- 2 ae 28.80 | 18.80 8.39 3.78 3.20 5. 84 62.15 6.32 5.08 2.61 5.45 4.99 55. 65 1.91} 17.22 4.78 3.31 2.21 aa. 79 | 19.95 | 28.50 2.56 8.90 ve eZe oN) |S recec||>asessqqSo5se5c 5.74 - 76 65. 35 8. 62 Ueto pe sqece = 3.34 2.27 53.80 | 13.16 GEES | oSseeeae 5. 80 3.60 63. 80 67003)" 132203) sbe~. >< 5.06 3.32 43.38 5.71 | 28.56} 1.31 5.53 2.56 1 Nos. 5 and 11 omitted. The average land value for the State should be compared with the total for land and all improvements except buildings on the 21 farms. The mean of the 21 farms shows 55.9 per cent and the average 57.9 per cent in land, fences, drainage, and water supply as compared to 68.1 per cent for the State. The mean shows 21.7 per cent and the 212 DISTRIBUTION OF INVESTMENTS. 25 average 20.2 per cent in all buildings as against 18.4 per cent for the State. Both percentages for the State would be lowered if ‘‘ Produce, supplies, etc.,’’ had been included in the census. The percentage invested in fences varies even more widely than the acre investment, while the percentages in drainage and water supply usually vary with the natural features of the farm. Farms 5,8, 10, and 12 (percentages of 8.41, 8.39, 11.87, and 9.18, respectively) have been tile drained over the greater part of their areas. A large part of the investment in water supply on farm 21 is chargeable to household. The percentage invested in live stock is within the limits of 10 and 20 per cent except for a very few farms. Farm 8 (live-stock invest- ment, 5 per cent) as shown by Table IV, has a low acre investment in live stock ($8.31 as against an average of $11.40) and a high land value ($87.74 as against an average of $46.25). The low percentage is explained by the fact that the owner has limited his farming operations with advancing age. The percentages invested in live stock and machinery as shown by the inventories are lower than they would be on a basis strictly comparable with the State average, as the 4 or more per cent in “‘Produce, supplies, etc.,”’ is included in this study and not in the census data. If the last item were omitted the average percentages for the 21 farms would be as follows: Land and all improvements except buildings, 60.4; buildings, 21.1; live stock, 13.1; machinery, 5.4. The values placed on live stock and machinery were probably on a higher basis in these inventories than census valuations, and all prices are undoubtedly higher than in 1900, hence, the comparison with the State averages is of less value than would at first appear. Farm 6 (with a machinery percentage of 11.82) has equipment for manufacturmg butter and maple sugar in addition to the ordinary machinery; and No. 7, a small farm with a machinery percentage of 14.10, has a portable gasoline engine and wood-sawing outfit, only a part of which should have been charged to the farm. Aside from these two farms the variation of the per- centage. invested in machinery is small as compared with other classes of equipment. DISTRIBUTION OF INVESTMENTS BY ENTERPRISES. Reference has already been made to the division of investment by enterprises. Table VII shows the average distribution of capital for the 21 farms, on the basis previously set forth. It will be noted that the land value is divided on the basis of acre- age, no differences in quality of land on the same farm being recog- nized. This suggests that a farm inventory be made to show the relative value of the various kinds of land, as, for instance, waste, 212 2°26 A STUDY OF FARM EQUIPMENT IN OHIO. dooryard, pasture, barn lots, crop land, orchard, and woodland. The crop land is included in one item under ‘All crops,” owing to the annual variation in acreage for the different crops. TaBLe VII.—Average inventory for a group of 21 Ohio farms, showing the distribution of investment by classes of equipment and by enterprises. Land. Pro- —__—__—_ Build- Drain-|Water | pive | chine | duce, Per Enterprise. ee dies ings. Fences. age. ae stock. | ery, La Total dent, (acres). Value. etc. ete. Generals. ---:2- 5.51} $246. 44) $325. a $533. 95 mt oe Bp sel CoM $237. 29)......- $1,344.19} 8.90 Household... -- 2.04) 91.01/1, ee sshasige 7 SS: 7|...----| 1,612.33] 10.70 abors ss 28sh23 -08 3.91 139 Be eee See 79.39) 0.53 Produce, sup- DUES EbC ee ale sae ee eee (G13) | Raae nee Sees 5 Bonscad boceceas Sacre $631.93) 1,398.50) 9.26 IOTSESee aoe eel sm ae oe soe 5s TE) SSeS a) ES 28. 52| $891.66) 77. 46)....... 1,075 51) 7.13 @attlessase—2- 25 |S oes be alone. S- NGS hire ease ee a bose 37.86} 582.26) 32.48)]....... 5) 5.34 SHEED ose cece nce [ae sacew seem e? CS | Ra ba ae 10.81] 201.05) 3.06)..-...-.- 280. 42} 1.86 INOgSoeccs es 2sels-s2eeo-|sse nee = 70|..------|------- 16.38} 158.34) 12.17]....--- 221.59) 1.46 Tesi ia eeAS eS Noth aes Rese See LCS) See ee eee 4.53} 52.60) 4.89]....... 102.85) .68 oa eee ee) ee too Geeeteee bo Scaae Ceeenaoe PemSeeery hose 2 3.20)|| pls50los oe 2 4.82) .03 AIStOCK. 0 2 46. 50|2,037.10| 63. 89)...-.-.- ee oe eee | ee 1059). oseos 2,113.72) 14.00 Aiiieropsse-._2— eR AE STG ARs - 5 se) ooeerige 362. 48)....-.-}]-------- LOZ 712322 4, 623. 11] 30.63 Gavin Sey bak ae el Ceres | I aS ben oh se sere bo sae baseman ase asoe 83.38) <== 5 << 83.38] .56 Smalloraime 3-6 se ae | bee eee epee emer leone |= een ae omen me 20:98)5-=2e—- 70.98] .47 TE Ley ee a rs trae tne nen Geo |e ee Eee ee eee [ee eee 65:53|- seers 65. 83 4 IROUHORS se a= apo cl- sees el steeee se SEY ssasose basa) oesmos) Pesce se5 20. 44|......- 24. O1 oik Heaters 2.98) 122.27 RG Ee eas ee ees eae bese- sce 35.96)... 2= 222 163. 68} 1.08 Orchard. 2.- 1595] OOHOOMS see Se Oe ae teh tote meses inter vole nee |b ete 73.39} .49 Woodland....-- Vr Wilh GY S358 8) |e eo) Seas he See Eo easad bossden sl boo-Ssai Ss sse=- 948.39] 6.28 BYE Gee ee A ee eee sees sel ie see Pe Onasese Resnaed| eoboono bogecdne Hi Pease 59} 004 Totale:_-- 165. 88|7, 676. 42/3, 049.47} 533.95) 366. 43) 171. 76)1, 889. 15] 773. 92 sy 93/15, 093. 03}.....-. Per cent... -22...<|---2<5<1 50.82} 20.21 3.54, 2.43) 1.14) 12.54) 4.67 19]. = ee 100. 00 The division of building values, based on the cubic space occupied by different enterprises, seems out of proportion, emphasizing as it does the much larger amount of space occupied in proportion to the value of “ Produce, supplies, etc.,”’ ($766.57) than of “ Live stock”’ ($436.51). The “Produce, supplies, etc.,” item under “Buildings”? might be divided between ‘All stock” and “All crops” but for the annual variation in the proportion of products fed and sold. The “All stock” building charge is based on space devoted to sheds, alleys, etc., or used in caring for several or all classes of stock. Buildings wholly or partly devoted to workshops or to the storage of machinery, wagons, and tools give rise to the amount charged to “General” ($325.42). A potato storage house and several sap houses were found. The term “Buildings’”’ includes both household and farm buildings. The machinery and utensils charged to household ($11.07) were those which on some farms might be used for either domestic or farm purposes. Each class of live stock is charged with the articles per- taining directly to it; also each crop enterprise. Vehicles for trans- portation and a large proportion of the smaller tools are charged to ‘General’? ($237.29), and plows, harrows, and other general crop machinery are charged to “‘All crops’”’ ($102.71). 212 27 DISTRIBUTON OF INVESTMENTS. “po}}TUI0 TT PUL ¢ “SON { Be ae ag AN) i cael 166). FL’ €L°& | 96° > a. 09°8 hie Tau eet se €P° 88° 09°26 Ga | — ieee Jaume gee aig 00°OF €°9 gg" Z0° 68° 16° cP* 70 61 61L°¢ 6SL°T 96° €6PF * GLP €¢° GZE "8S | 8L°ET CFO” 8z°9 | 19° ot’ | pe | ue | 9g €9°08 | 00'FE | 80° g¢° €¢° 13° GG '°06 | SG °LT 60° 5 neil 280" | 0" 1@°6 | 20°18 | Zr" cae acto this FL 81 | 0S'2r | 20° gg’ 02° cI’ 69 '°GG | LEEDS 96° 06° | oF | 0s" os'92 | 0z6 [tt oo (om tP° og* OPEPSO9 2 ilhe ars .S oz | ge: | ue 10°08 | $661 | 10° IZ Orla (ete | pesepaeese [te Giteel| cages eener . || cai v1° 61% £6° Igy Ly’ SI's | €8°T SP * (ag CET Leal ee pees €9" Tos |" CLT 16° Lie CBee is 19° Gila lis €8° 80° 88° 18) eal GSO MAO | eR Tc ; -[n0.y ss0y{ | ‘deoyg eSveiov) osei0ay y ‘SULIVE 1Z JO dnows 10,7 “ULI JO WOTYeUsTSaqT 98°§ | 09°6 8¢* L¢°6Z | OF CT OFS | OO'IT Gls ¢c0 OL | OL 2 Goh | 69°9 TSO) wins 7) S659) | GFZ 6h Fr | F0°9 GO'9T | ST'T 99°81 | #2°8 cr6"G | S8°L G9E"6 | SFR” LEE ‘IL | 0L°6 Pes | Siz 96 6 g¢° OL ‘OL | 06°8 pee cnete 2 ““Qtun tr 6 S1'8 DSR R NAIF em 98 °ST | 06 °ST 1a'F €L°8 Cena line eam OWL SCs StL | oo €€'9 161 62 °9T | 26 "ST Cee eon o9°OT | OLS 887 | ZT IT 09 °IL | OL IT GRALT a5) cee alh O8i8 088 16 Tt | OFS COSGIs nme eee CorOmsNOUns WoL | LSS OL'6) | S252 cht | 706 €9°9 | S¢o°6 96°E | F9°L 00°L | 81°8 LE°% | 26'°9 IgG | 79°9 ¥O'S | &9'8 00ST | OF 6 8h'S | 62°IT 186 | 02° 90°€ | 612 00°ZL | 98°6 Go°L | 96'S 0c’6 =| &0°9 (Al |rizgete CP OT | €8°8 0Z°§ | S9°LT 68°38 | ST 6T OLS | 80°ET TICE | 09ST 02 ET | S8°2 82°6 | &2 IT Go 'T LZ OT Z'0Z | G06 OF OT | 98° LOT | 10°OT 98°IT | 9L°T 00°81 | Lh’P “Arrep ; ‘ pues |‘sosioyy | e8v10}g) “10Ge’T | _ Pog al beet ere9 asnoy{ | -uey supfasayy fo Te fo dnoib v 10f sabpiaan pup sun ym ‘suf oryQ ¢¢ Uo asriudsaqua yooo ur paysarur poridvs wanf yv}0) fo 96nj}W204aT— TILA FTAVL 212 28 A STUDY OF FARM EQUIPMENT IN OHIO. Table VIII gives by enterprises the percentages of total invest- ment for 25 farms, together with the mean of the percentages for the individual farms and the average percentages for the 21 farms con- sidered as a unit. Miscellaneous enterprises are grouped under the column so headed. These include maple sugar, sirup, etc., on farms 1, 2, 5, 6, and 17; orchards on farms 3, 21, 22, and 23; sugar beets on farm 10; tobacco on farm 24; and market garden on farm 25. On farm 4, 8.65 per cent is invested in the maple-sugar enterprise and 1.68 per cent in orchard; on farm 18, 0.28 per cent is in sugar and 0.97 per cent in orchard. Bees, also included with miscellaneous enter- prises, average 0.03 per cent of the total, amounting to less than 0.4 per cent on any farm represented in Table VIII. On farm 29, however, this enterprise represents 2.51 per cent of the total invest- ment. The relative importance of the various live-stock enterprises can readily be ascertained from Tables VIL and VIII. On high-priced land the “All crop” enterprise naturally bears a higher proportion of the total investment. The investment in special crop machinery is relatively small. The low figures (0.15, 0.10, 0.07, and 0.21) for corn machinery among the hill farms (20 to 23, inclusive) are to be noted. The distribution of capital for each farm is worthy of consideration by itself. It is not easy to generalize in this connection, all the factors discussed up to this point governing the selection of equip- ment. The various tables, and especially Table VIII, will show the difficulty of studying the farm instead of the enterprise as a unit. Farms 1, 2, 6, 9, 21, and 23 might be classed as dairy farms, yet in the distribution of investment among the various enterprises they are far from uniform. With the exception of these and farms 20 and 25, the farms studied can best be classed as “General,” and among these occur variations in the distribution investment to the under- standing of which an analysis of the farm as a combination of enterprises is essential. EQUIPMENT OF THE AVERAGE FARM. In the foregoing pages the distribution of capital at the time of inventory has been discussed. The next phase of the study, and really the first in logical order, is the enumeration of the items that make up the equipment of an average farm. The average equipment of the 21 farms which have been studied will, of course, serve only for farms having approximately the same conditions as this aver- age farm. The various classes of equipment will be dealt with 212 EQUIPMENT OF THE AVERAGE FARM. 29 separately in the following pages and in sufficient detail to permit the application of the data to farms diverging from the type under consideration. It is impossible to make a general recommendation as to equipment, owing to the complex and varying combinations of enterprises on different farms; the summary presented later is there- fore valuable in a suggestive way only. REAL ESTATE. The average value previously shown for the bare land is taken as a basis instead of the mean value, as all other data relating to the first cost of equipment are based on averages. The cost and present value of drainage systems were regarded as equal, as before stated, but the first cost of buildings, fences, and water supply will be higher than the values shown in the preceding pages. The various improve- ments will be discussed separately. HOUSEHOLD BUILDINGS. The great variation in the tastes and circumstances of farm owners is largely responsible fcr the variation in the cost of house- hold buildings, and it is almost impossible to arrive at a satisfactory basis for determining the proper outlay in this respect. Table VII shows that on the 21 farms studied the inventory value of household and tenant buildings was approximately equal to that of farm buildings, each being about $1,500. This, however, does not repre- sent the present cost of construction. Household buildings were not studied closely as to size and cost, but from the values shown in Table III (p. 18) and such data as are at hand it is estimated that to replace those found on the 21 farms would involve an expenditure of $600 to $4,000 per farm, averaging close to $2,500. This would include dwellings for owners, tenants, and laborers; woodhouses; smokehouses; milk cellars; ice houses, etc., some of which might also be used to some extent for the farm. SPACE NEEDED IN FARM BUILDINGS. The farm buildings must usually provide for the shelter of horses, cattle, sheep, hogs, and poultry, and for a certain allotment of space to be used by or devoted to the care of several classes of live stock. They must usually accommodate all or a large part of the products of the farm fields, including roughage, grain, and seed. They should provide space for the storage of all wagons, machinery, and tools, and for the farm workshop. A provision of easily accessible space should 212 30 A STUDY OF FARM EQUIPMENT IN OHIO. also be available for the temporary shelter of machinery, live stock, or products. Buildings for special purposes, such as the storage of root crops and ensilage and: the manufacture of maple products, are necessities on some of the farms. In studying this problem the size and plan of each building was noted, together with the enterprises to which each building was devoted at the time. The extent of floor and cubic space devoted to the various enterprises has thus been approximated. The thick- ness of walls and partitions was not considered. While averages of the 21 farms do not include enough cases to justify the drawing of general conclusions, the data contained in Tables IX and X afford a rough working basis. Table IX includes data concerning enterprises the space for which depends to a considerable extent upon the size of the farm. The term ‘‘General farm” includes all space devoted to machinery storage, workshop, driveways, and other spaces devoted to the farm as a whole. ‘‘Hay storage” includes the area and vol- ume of mows and lofts, the volume being greater than the space ordinarily filled with hay or other roughage. The proportion of the entire volume of mows which could actually be filled by the ordinary methods could not be satisfactorily determined at the time, and the space usually filled was extremely variable; hence, the total volume was used in this table. ‘‘Grain storage” includes separate cribs and granaries, also all bins and storage places for grain and seed in other buildings. TasLe I1X.—Average area and volume of space devoted to the storage of products, machin- ery, etc., in buildings on 21 Ohio farms. Average per farm. Average per acre. Average per acre of Enterprise. Square feet.| Cubic feet. | Square feet.| Cubic feet. | Square feet.| Cubic feet. 2,038 24, 732 12.3 149.0 23.7 © Goeneralifarms 25.5. -5-- 56) 288.5 (HayiStorages seen sees ates 2, 752 46, 558 16.5 280. 6 32.1 543. 2 Grain storage.-:.--=.-.252-.02 505 5, 192 3.0 31.3 5.8 60. 5 The average space per acre shown in Table IX would tend to vary inversely with the size of the farm. On the smaller farms the amount of waste space would be greater for each enterprise and the space devoted to certain general farm purposes would remain practically the same as for the larger farms. Table X shows averages in connection with the space devoted to live-stock enterprises. In order to obtain comparable units all young stock except colts was reduced to the basis of mature animals. Two head of young cattle, 2 shotes, or 5 pigs were regarded as equivalent 212 EQUIPMENT OF THE AVERAGE FARM, 31 to 1 mature animal. Since young lambs are later included with the ewes in Table XIII, no correction for them was necessary. The space in harness rooms is included in that shown for horses, and space devoted to milk rooms, etc., in that shown for cattle. For sheep the space includes both floor and rack room, with very little waste. For swine the space shown includes feed alleys, etc., in hog houses. The average space per head is of course much too small for the entire herd of swine. Only 11 out of 21 farms show a definite space devoted to swine, and on the other farms swine usually occupy a portion of the ‘“All stock” space during part of the year. Portable houses for the brood sows are in common use. Such portable houses, averaging 4.1 per farm, were included with the miscellaneous items of equip- ment rather than with permanent farm buildings. TABLE X.—Average area and volume of space per farm and per head devoted to live-stock enterprises in buildings on 21 Ohio farms. Approxi- Average space per Average space per mate num- farm. head. Enterprise. ber of ani- mals per Area. Volume. Area. Volume. | Square feet.| Cubic feet. | Square feet.| Cubic feet. 613 5, 242 87.5 748.8 EG ISOS eR stare ee ac seceene OP HSS ae Cee oe ee ee Se ae eS 13 1,084 9, 210 83. 4 708. 4 SLE ee tesa pee See eee eee el 41 475 4,141 11.6 100.9 ease ya Sete eierora ena Siateaw a miemmniae'e 17 327 2,912 19, 2 171.3 PRINS ace me eet ee ee earner, See oe eee 448 SAGO b | Nee ee tea tre eee ee SIZE OF FARM BUILDINGS. It is possible to plan a practicable set of farm buildings which will almost exactly fit the conditions of the average farm under consid- eration. The size and nature of the buildings must of course be varied to fit any individual conditions, but assuming that the data in Tables IX and X give the requirements for this particular size and type of farm, the size of the separate buildings is the next item to be determined. Basement barn.—Of the barns on the 21 farms about half were base- ment or ‘‘bank” barns, and in most of the others the space equivalent to a basement was provided by attaching to the barn unsightly sheds of the lean-to type. On most farms a convenient site for a basement barn can be had without excessive grading, and the advantages of this type are such that they will be provided for in the barn to be planned. Horses, cattle, and sheep are often sheltered in the basement of a barn. Such a barn 36 by 60 feet provides 2,160 square feet of floor space (outside measurement), while the requirements for the 32 A STUDY OF FARM EQUIPMENT IN OHIO. three classes of stock total 2,172 square feet, these requirements also being calculated on outside measurement. A section 16 by 36 feet at one end will provide 576 square feet for horses, and an additional space 4 by 9 feet would utilize the average space allotted for harness. The 16 feet would be reduced by the thickness of the wall, but would leave ample room for manger, stall, and alley behind'the horses. The 7 horses could easily be accommodated in the width remaining after the thickness of one wall is deducted from 36 feet. As a rule, in barns of this kind the basement wall is provided only on the two ends and the long side next the bank. A section 30 by 36 feet would provide 1,080 square feet for cattle where 1,084 are required. This would afford ample space for the average of nearly 8 cows per farm, for the young and miscellaneous stock, and for a milk room if desired. While there is thus abundant space provided for this number of cows and young stock, it must not be understood that such an arrangement is in any way ideal from the standpoint of a modern dairy barn, as it would be difficult to secure sufficient light and other sanitary arrangements. Experts in sanitation also would object to having the milk room in the cow stable. If it were a beef farm there would be less objection and the space provided would afford room for the miscellaneous stock on a beef farm and feeding room for a small carload of steers. The sheep would preferably be lodged in the center space, in which the harness room and a stairway could be located. Deducting the area of the harness room from the remaining space, 14 by 36 feet, 468 square feet are left for sheep, the average requirement for sheep being 475 square feet. A height of 83 feet would supply 18,720 cubic feet in the basement, where 18,593 cubic feet is the average require- ment. In this plan both horses and cattle are provided with more and sheep with less cubic space than is called for by the average. A basement. somewhat similar to the one just described was found on farm 3. The upper part of this barn is adapted from that of a barn 40 by 60 feet on farm 14. A central driveway 14 feet wide extends through the center of the barn, making a floor space 14 by 36 feet available for general farm purposes. To the left of the driveway is a stairway to the basement, the remainder of this end of the barn being devoted to hay storage. On the right of the driveway a grain room 10 by 23 feet and aspace 26 by 23 feet for storage of wagons and machinery occupy the floor space. A mow floor extends over these spaces at a height of 8 feet, and over the driveway at a height of 12 feet. The barn is 18 feet from the top of the basement wall to the corners, or to the ‘‘square,” and a roof of one-third pitch gives an additional height of 12 feet to the point of the gable. This provides 2,160 feet of 212 EQUIPMENT OF THE AVERAGE FARM. 33 floor space for hay and 230 for grain storage; but, since volume is rather the essential, it provides 39,168 cubic feet for hay and 1,840 cubic feet for grain, leaving balances of 7,390 cubic feet for hay and 275 square feet and 3,352 cubic feet for grain to be provided elsewhere. In the driveway 14 by 36 feet, and storage space 26 by 23 feet, an area of 1,102 square feet and a volume of 10,832 cubic feet are provided for general farm purposes, leaving a balance of 936 square feet and 13,900 cubic feet to be provided for general purposes in other buildings. The cost of this barn will vary with many factors and can more easily be estimated by the contractor than the necessary size; hence, dimensions only are emphasized in thisstudy. A study of cost items of four comparatively new barns of similar type indicates that about 4 cents per cubic foot inclosed will cover the cost of a barn of this size and type. Ohio farmers who have timber available commonly utilize lumber sawed on the farm, the exact value of which it is difficult to estimate. This barn contains 70,560 cubic feet; at the rate given it would cost close to $1,800, but this is probably a low estimate. Hay barn.—Where a basement barn is not practicable a second building is usually provided for the storage of hay and the shelter of a part of the live stock. On some farms such hay barns are made large enough so that sheds attached to the barns are dispensed with. In order to provide for the additional space (448 square feet and 3,925 cubic feet) required for ‘‘All stock” and for the additional storage of hay, a building of this sort is here planned for the average farm supplemental to the above-planned farm. To combine the cubic space required for both purposes with the floor space required by ‘‘All stock”? would result in a building of unusual proportions, hence the ground area is increased from 448 to 512 feet as shown in Table X. A building 16 by 32 feet, 16 feet high to the ‘‘square,”’ with roof given one-half pitch will give an excess of 64 square feet and 171 cubic feet for ‘‘All stock.” If the second floor is placed 8 feet above ground it will also provide 6,144 cubic feet for the hay storage, as compared with the remaining requirements of 7,390 cubic feet. A further increase of floor space accompanied by a decrease in height would improve the proportions of the building, though they are not unusual. This building may be of cheap construction; $150 should cover the cost. Wagon shed, crib, etc—The grain room in the basement barn failed to provide for a large part of the space required for grain storage. The ratio between floor and cubic space remaining suggests a high crib or granary. A popular building is a double crib, or a combination of crib and granary, with a driveway between, which, when inclosed by doors at either end, may be used as a convenient 212 34 A STUDY OF FARM EQUIPMENT IN OHIO. wagon or buggy shed. seeieimina. cee oie. 185. 25 505. 6 77.2 | 1,027.6 1,610. 4 5.03 3.56 8.7 2A te BOC D DEE OE EEE oe pee oe 228. 62 176.4; 390.8 956.8 | 1,524.0 4.00 3.60 4.9 PP. ast ae ee ee ee 156. 00 329.2} 190.8 579.6 | 1,099.6 3. 24 2.35 4.8 Pee = tae cto enn aiie.c erate sates. sini 177-27, 291.0 | 409.1 734.1 1, 434.1 5. 80 4. 06 8.1 For the group of 21 farms:! Average (acreage unit). - - 165. 88 292.19! 273.26 644.11) 1,227.93, 4.60 Bee 7.4 rereentiol total ose. =. os|52=) <5 2.33 24.1 22.5 Done LOO! ORE cease alees So GORE eee. Mean (arm nib) s.- 455.) 32.25 be |e otc c8k spa cok ade ee ee 4.79 3. 40 7.67 1 Nos. 5 and 11 omitted. The character of fences on the 21 farms is brought out in Table XII, which shows the extent of each of the eight principal kinds of fence and the average cost per rod of all fence on each farm. The total of the eight kinds shown averages 1,204.6 rods per farm, or over 98 per cent of the total, a few miscellaneous kinds being omitted. The cost of the various kinds of fence varies with the difference in the cost of materials in different localities, but even more with the height, num- ber of wires or boards, distance apart of posts, and the labor ex- pended in construction. Woven-wire fence, for instance, may be 5 feet in height without barbed wires in addition, or 3 feet in height with several barbed wires above and. one below. It may be made of either heavy or light wire, with posts 10 to 33 feet apart, the posts costing 10 to 30 cents each. Owing to these variations, estimates of the cost of construction can hardly be made general. 212 38 A STUDY OF FARM EQUIPMENT IN OHIO. TaBLE XII.—Number of rods of each of eight principal kinds of safe maintained by the owners of 21 Ohio-farms, with the average first cost per rod of all kinds of fence on each farm. Woven See Smooth | Worm | Straight | ,; Average wire. wire. wire. Board. rail. rail. Picket. | Hedge. =a Farm No. 2 enees SSAVSASSARSRSSSRs NNOMWWWDOWOKHUFOOOKRNMOROD ee ees ~I a For. the group of 21 | farms:! | Average. .......- 299.0 184.8 63. 6 96.4 393.4 38.5 103.7 ras | 59.7 Per cent of total 24.8 15.3 5.2 8.0 32.6 3. 2.0 | tae 1 Nos. 5 and 11 omitted. The old “ zigzag’ or “worm”’ fences are still much in evidence, but are being replaced as they decay, largely by woven wire. A small percentage has been rebuilt as straight rail fences. The use of barbed wire is somewhat restricted by law, but it is popular as a cattle fence. Board fences and picket fences (usually made of wire and pickets) are still used to some extent for tight fencing, but are being replaced by woven wire. The hedge fences (usually of Osage orange) are being destroyed on many farms, not only because of their unsatisfactory character and the labor of keeping them in shape, but because of the ground rendered unproductive on either side of the fence row. The smooth-wire fences include various types represen- tative of the effort to supply a fence safer than barbed wire and easier to put up than woven wire. Regarding the cost of construction at the present time, it may be said that this applies almost entirely to board and barbed or woven wire. Hedge fences were formerly installed at about $1 per rod and entail an expense of 5 to 10 cents per rod each year for trimming. Reference has already been made to the cost of building old rail fences. The labor cost probably ranged between 30 and 50 cents per rod. The material was not valued, and in fact often had no market value at the time the fence was built. The rebuilding of rail fences costs 20 to 30 cents per rod for labor, and if the rails are fastened to posts 212 EQUIPMENT OF THE AVERAGE FARM. 39 one post will be required for each 11-foot rail length. Picket fences require 1 to 1? posts per rod. The pickets, wire, etc., cost 60 cents to $1 per rod, and the labor of erecting 15 to 20 cents per rod. None of these types are now built to any great extent. Barbed-wire fences for cattle usually consist of 3 or 4 wires at a cost of 3 to 4 cents per rod for each wire. Posts are usually set 11 to 22 feet apart, costing 5 to 8 cents per post for setting. They are of oak, chestnut, catalpa, Osage orange, locust, and cedar, principally, costing anywhere from 10 cents up. The corner and brace posts cost from 50 cents up for the posts, and from 50 cents to $1 for setting. Woven wire costs 25 to 75 cents per rod for the usual heights and grades, the lower heights usually taking several strands of barbed wire in addition. As a rule posts are set 11 to 33 feet apart. Set- ting of posts for woven-wire fences costs about the same as for barbed wire, but the end posts must be heavier and more firmly braced, costing as high as $3 on some farms for post and setting. The labor of erecting wire fences, outside of setting posts, is estimated at 5 to 10 cents per rod, but accurate figures are not easily available. This refers, of course, to ready-made fence, i. e., not woven on the ground. Board fences usually require two or more posts and 25 to 40 feet of lumber per rod. The rise in price of fence lumber has practically restricted board fences to the lots about the farmstead. While the estimates must be varied to suit conditions, it is probable that 45 to 60 cents per rod for barbed wire, 60 to 90 cents for woven wire, and from $1.25 up for board fences will cover the cost. DRAINAGE. The investment in artificial drainage shown in Table VII (p. 26) represents the cost of installing such improvements. Only afew farms have practically all fields drained. Figure 2 represents the drainage system on farm 10, as shown on the owner’s map, all of the farm except the wood lot being tile-drained. The owner’s map shows the size, depth, and location of all tile, this being very convenient when drains are to be cleaned or new ones installed. The cost of the drainage on this farm was $17.70 per acre for the whole farm and about $18.60 per acre for the area drained. The average of the group of 21 farms showed an investment of $366.43 per farm for drainage. At the rate prevailing on farm 10, this would tile about 20 acres thoroughly. In practice, however, “‘strings”’ of tile are found only in the low places, and a much larger area could be drained. The work of digging the ditches and laying the tile was often done by contract at the rate of 6 to 10 cents per ‘‘rod-foot”’ for small tile, 1. e., a ditch 1 rod long, 1 foot deep, and wide 212 40 A STUDY OF FARM EQUIPMENT IN OHIO. enough to admit tile 2} to 5 inches in diameter. At the present time the cost of laying tile is considerably greater. For central Iowa in 1910 the prices for laying tile were about as follows: For 4, 5, and — ie Oo ai 5 7 Pray Aes le sh ; | | | | it | i =I Wy ioe : | R % a LO | | call bh. {I te gee i | | | | i: mn ee eee ae ae ee Fig. 2.Plan showing the drainage system of farm 10, in Putnam County, Ohio. 6 inch tiles laid 3 feet deep, 44 cents per rod, with 1} cents additional for each inch over depth, the owner filling the ditch; for 8, 9, and 10 inch tile, 624 cents per rod, with 24 cents per inch additional for 212 EQUIPMENT OF THE AVERAGE FARM. 41 every inch over depth; for 15-inch tile, 95 cents per rod for a 3-foot ditch, with 6 cents additional per inch for over depth. Practically no tile as small as 24 inches in diameter is being used on farms at the present time, and many factories do not make sizes less than 4 inches in diameter. Filling the ditches is usually done by a team and plow at very slight cost. The tile varies in price with locality. The average prices of a number of firms in the Central West in 1910 were about as follows: 3-inch tile, $12.50 per thousand tiles, each tile being 1 foot long; 4-inch tile, $17; 5-inch tile, $23.50; 6-inch tile, $32; 7-inch tile, $42; 8-inch tile, $53; 10-inch tile, $81; and 12-inch tile, $104 per thousand. ~ WATER SUPPLY. Owing to the wide variation in the character of water systems, it will hardly be possible to make even an approximate list of the essen- tials for the average farm. The average present value of the water system, appraising wells at the cost of installation, and pumps, tanks, etc., at their present value, is seen to be $171.76 (Table VII, p. 26) for the group of 21 farms. Allowing for depreciation on the latter items, it is probable that the average cost would reach $225 for the entire system. Between different farms, however, there is a wide range, as shown by Table III (p. 18). The larger number of these farms depend on dug wells 25 to 40 feet in depth and 3 to 4 feet in diameter. Such a well, for digging and walling, costs $1 to $1.25 per foot in depth. A hand pump, costing from $5 to $10, is usually installed in such well. Some of the farms have drilled wells 90 to 150 feet deep. These cost about $1 per foot for drilling and casing and require a more expensive pump, costing $15 to $25 for the pump, piping, and cylinder. One or more cisterns are usually found, rang- ing in size from 20 to 150 barrels and costing $10 to $35. A cistern pump complete usually costs $4 to $6. Where water is conveyed to tanks or troughs at some distance from the well, 1-inch or 14- inch piping is ordinarily used, at a cost of 8 to 12 cents per foot. Small wooden troughs, holding 1 to 3 barrels and costing $3. to $5, are often used in connection with wells or cisterns near the barn, but tanks holding 10 to 50 barrels are commonly used in feed lots. These cost from $10 up in wood, and a trifle more in concrete. Many per- manent concrete tanks are being installed by farm labor at a cost of $15 to $40 for sizes ranging from 20 to 80 barrels. Windmills cost- ing $50 to $150 are often found economical. The usual height of the tower is 25 to 30 feet, with a wheel 6 to 8 feet in diameter. A tower costs about $60 to $70. Gasoline engines used only for pumping are occasionally found. These are usually of 2 or 3 horsepower and 212 492 A STUDY OF FARM EQUIPMENT IN OHIO. cost $75 to $150. Reservoirs are sometimes found necessary in con- nection with deep wells and windmills. These store up a surplus of water at a depth from which it can be easily pumped by hand when lack of wind cuts off the supply from the well. The cost of construc- tion is about the same as for cisterns. PERSONAL PROPERTY ON THE AVERAGE FARM. “he requirements of the average farm as to live stock and machin- ery are discussed in the following pages, including Table XIII, which was compiled from the inventories. HORSES. In Table XIII the horses and mules on the group of 21 farms are divided into 5 classes with respect to use. The general-purpose, draft, and draft-and-brood classes might be grouped as work animals, with an average of 4.48 per farm, but the subdivision indicates a little more clearly the character of the animals. The draft-and-brood ani- mals are mares regularly worked rather than mares kept for breed- ing purposes only. The general-purpose animals are those used for both work and driving on several small farms. The data indicate that 4 work horses, 2 head of young stock, and either a driving horse or brood mare, which may occasionally be worked, are about the average requirements as to horses. The 94 horses used partly or wholly for heavy work on the 21 farms averaged 1,250.3 pounds in weight. From Table II (p. 12) it will be seen that these farms averaged 85.71 acres of harvested crops. This would mean an average of 19.13 acres of crops per work animal. The acres of crops per work animal varied from between 10 and 11 acres on farms 3, 7, and 22 to 31.1 acres on farm 17. On 55 farms visited by Mr. Thompson and the statistical cooperators, 8.4 horses were found to be the average per farm. On 54 of these farms, from which data were more complete, averaging 199.55 acres in size and 125.54 acres in harvested crops, an average of 5.39 work horses per farm was found, and the acreage of harvested crops per work animal averaged 23.3. On one group of 27 farms, averaging 153.65 acres in size, the acreage of crops per work animal averaged 18.9, and on a group of 17 farms averaging 272.44 acres the average crop area was 27.5 acres per work animal. The farms in Ohio visited by Mr. Thompson were mostly in the southwestern part, the level, ‘‘large-farm”’ area. On 17 farms visited in 1907 and 1908 by him 119 work horses were kept, averaging 1,368 pounds in weight, with an average value of $158.91 and an average 212 EQUIPMENT OF THE AVERAGE FARM. 43 age of 8.98 years. On farms 20 to 23, inclusive, in the “hill section,”’ 17 work animals, averaging almost exactly 7 years in age, and 1,170 pounds in weight, were valued at $146.41 each. These 4 farms aver- age 186.79 acres in size, but average only 65.4 acres in crops, or 15.4 acres per animal. On 52 farms, including those of cooperators, 275 work horses were kept, averaging 1,306 pounds in weight. The work stock, like machinery, is seldom utilized to its full capac- ity on small farms or where conditions cut down the crop area. The number of work animals needed depends not only on the acreage of crops, but upon the total area of the farm, the kind and extent of live-stock enterprises, the kind of crops, the topography, the dis- tance of the farm from town, and numerous other factors which can not be studied in detail at this time. On most farms the number of work animals is determined by the mimimum power requirements during the two busiest seasons—seed time and harvest time. CATTLE. The values for cattle on this group of 21 farms in the spring of 1909 are approximated in the column of “Value per unit’? (Table XIII). These will of course fluctuate with the market, and round numbers (based on averages, except as otherwise stated) are used for con- venience. The value of $100 has been arbitrarily set as fair for a good bull of either a beef or dairy type, and $40 has been taken as nearer the usual value of a beef cow than the actual average on two farms reporting. On one of these farms 14 Shorthorn cows were valued at $100 or more each, and on the other 4 grade cows were valued at $35 each. Steers were figured on the prices of 4 to 44 cents prevailing at that time, and young beef stock at about the average value per head. On farms 1, 2, 6, 9, 21, and 23, on which dairying is the principal enterprise, 95 milch cows were kept, averaging $40.80 per head. These included some pure-bred cows. On 10 other farms there were 29 milch cows, averaging $37.72 per head. The average value of 124 cows on 16 farms was $40.18 per head. The 6 dairy farms aver- aged $648 worth of milch cows per farm, and the 10 other farms $109.40 per farm. On the 6 dairy farms there were 44 head of young stock, or nearly 1 head for each 2 milch cows. The figure for the value of young stock is close to the average for all calves and heifers found on these farms. SHEEP. The value of $10 per ram is a trifle higher than would be true of many farms, owing to the presence on farm 17 of a number of rams which were raised for sale as breeding animals at $12.50 each. The 212 44 A STUDY OF FARM EQUIPMENT IN OHIO. figure given, however, is not too high for good results, All lambs at foot are included in the value of the breeding ewes. Feeding wethers, lambs, and ewes are grouped under ‘“ Wethers, etc.’’ SWINE. Swine are quoted at a round figure approximating the average value on these farms at that time as follows: Boar, $15; sow, $14; shoat, $5; pig, $2.50. Several fat hogs are included under “shotes,” and the dividing line between ‘‘shotes” and “pigs” is not well defined. About 54 cents per pound was the farm value of hogs at the time the inventories were taken. MACHINERY, TOOLS, ETC. As stated elsewhere,! the first cost of the great number of minor articles of farm equipment not mentioned in Table XIII would probably be from $200 to $300 by the time the outfit was complete for the average Ohio general farm of 160 acres. This figure, however, would include an appropriation of $50 or more for repair materials, which in this report are invoiced with ‘Produce, supplies, etc.” Taking all the minor items other than repair materials for 33 farms, using the ordinary retail prices and dividing by the number of farms, the first cost of minor items for the average farm of 167 acres was found to be about $190. In taking an inventory of the small items many were doubtless omitted, and $200 is probably a figure low enough to allow for the average equipment of this sort. The values for harness, machinery, etc., in Table XIII are as nearly as can be ascertained, the usual retail prices prevailing in Ohio for new articles. Both farmers and merchants were consulted in the effort to obtain these prices, but, of course, the figures given .are merely suggestive. The “First value” cost shown in Table XV in- cludes both first and secondhand prices and may be regarded as indicative of the usual farm practice. In making up a list of machinery for the average farm so many factors enter into consideration that a generalization would be of little value. The number of any single item reported for all the farms, the average for all farms, the percentage of farms reporting the article, and the number of articles per farm reporting are all to be regarded as useful in separating the necessary items from those only occasionally or rarely used. <2 -diesinescs - 27 21 1.3 1.29 15. 00 19. 35 Spring-tooth harrow .........---.--------- 7 6 152 33 16. 00 5. 28 INCTHEMMBITOW erioe = aso 2 ssc cenclsceee ee 1 1 1.0 05 18. 00 90 Disk or cutaway harrow.......---...--.--- 18.5 19 1.0 88 33.00 27.94 IRGIEROCCLOSHER sss jc. cee scae ese coe 13.5 14 1.0 64 25.00 16. 00 BIBW Ren saa isco slalom ais cisie.e cece ceed oe 11 10 By 52 3. 00 1.56 Wileedentrs-so-cc ss nct eee ensatececsteece ce 14 15 9 66 10. 00 6. 60 DNGVEUDIGW se acoaa-c= = gaa aeaee een 15 14 Pal 71 2.50 1.78 Manurespreaders..)- - cc sees eccec scenes 11.5 13 .9 54 125. 00 67. 50 @arnnialeCuiteles o~ a- c/o oe eae eae sais ao 8 1 1 1.0 05 25. 00 1.25 Farm wagon and box...................-. 28 21 1.3 1.33 75. 00 99. 75 Truck or “‘handy” wagon................. il 11 1.0 52 30. 00 15. 60 Spring wagon.............- ate il 10 1a 52 75. 00 39. 00 OAMIEALE set cig ome a a mtyie e's hones fs ae 6 5 152 28 25. 00 7.00 IEESRUCHELS Stace ots s ors schss stl sae necn eee 4 4 1.0 19 5. 00 95 Carmiste oe meses 8h spdem succes toc leet 14 13 ileal 66 100. 00 66. 00 AS ir ista a SEE Be es ee eee ae ee 33 20 1.6 1.57 75. 00 117. 75 Lee ooo ahs Soedee sSedeneahews 20 15 153 95 30. 00 28. 50 Cutterorslelehs 2... ss 5ssces sees eens 9 9 1.0 42 30. 00 12. 60 VOR ORR pte So. ei Ga Seis ee oe eee asenee 3 3 1.0 14 3. 00 42 SUSTTE)Ta 7 ee hee A ee es aie 15 10 1) 71 2.00 1. 42 SLOCKTACK a athe h oe aes He aae eee cece ewes 5 4 1.3 23 10. 00 2. 30 Gravelor dumpibed:~- 2/5... 222-222-2208: 3 3 1.0 14 6.00 . 84 DETAPOLOLSUD eos n eee nace soon otemeiecoee 3 3 1.0 -14 5. 00 - 70 GASGNNGONPIIGs..0) cockeeecsoese jose ces 5 5 1.0 93} 200. 00 23. 00 IBSDCOCKLESLOL~~ - =) Soe sisies- oleae estes 2 2 1.0 -09 5. 00 ~45 PROT OMe eae Satan eee cee see meceee cls 1 1 1.0 -05 5. 00 -20 LGM IPOTALON a aos soc. stie sees ee ooo sone See 1 1 1.0 -05 15. 00 -75 Cream separator so. -0o525--o22)2-22 055-556 8 8 1.0 .38 65. 00 24.70 Combination Churn... 0-52-2250. aeenes en 1 1 1.0 -05 30. 00 1.50 Corn planter; I-horses 2-52.26. soscace ee 3 3 1.0 14 18. 00 2. 52 Orman kerses oto ah sccced us Uscdanoess 6 6 1.0 28 2. 00 - 56 Corn planter, 2-horse...........----+------ | 8 10 8 38 50. 00 19. 00 Cultivater, Zor S)HORSAS. 3... 4 lecececicee 30 17 1.8 1. 43 28. 00 40. 04 WHULVALOES T-HOISGen a cee sae cca e eae odes 27 18 1.5 1228 5. 00 6. 40 GOnmpinder: eee eee see eyes eee | 4.75 6 AY “Pal 125. 00 26. 25 FS) (Ge ULE £92 2121: Ra ee ) 2 2 1.0 09 25.00 2.25 1 Machines owned in partnership account for the fractional numbers in the first figure column. 212 46 A STUDY OF FARM EQUIPMENT IN OHIO. TasBLeE XIII.— Major items of personal property found on 21 Ohio farms, with the average number of each item for all farms and for each farm reporting the item, the approximate value of each item, and the average value of each item for each of the 21 farms—Contd. Number. Value. Designation of item. | Farms | Average | Average Total per Reported. reporting.| Pet farm | per farm, | Per unit. | farm, all ‘POrtNs - reporting. all farms. farms. Comn'ShoCK en si se-eissiee ae eee oem aici te 2 2 1.0 0.09 | $120.00 $10. 80 Cormishradden- cut ee one cee poet an 6 2 -3 - 03 175. 00 5. 25 Ensilage or fodder cutter.................. 6 6 1.0 . 28 40. 00 11. 20 Comnisheller-22h3 Ss - e: seo oes tae ee! 14 13 1. . 66 6.00 3. 96 Circular woodsaw: =-...5..202.- Pel a Vl a cn ea = a WV Walking plow.......-.-..- 115/313. 60) $6. 95'$10. 62) 9.6)$0. 69) 5.1 $0. 71/$0. 53/$1. 93|27. 1/$0. 018 $0. 359/30. 072 Riding (or gang) plow.-...] 42) 47.22} 33.05| 40.17) 5.6] 2.54) 5.4) .96) 2.01) 5.25/28.8] .017) .42 | .183 Harrow; Spikes.) -- = - 7A] 12.47) 6.83} 9.99] 8.3] .68] 5.5) .29| .50) 1.47/79.2) .005| .108} .019 Harrow, spring..-.----...- 16] 17.00} 7.72) 12.88} 9.0} 1.03] 6.0} .21) .64] 1.89/38.8] .009| .17 027 imo AGISK es. S55 2.2% 62) 26.90) 14.93) 21.62) 7.4) 1.62} 6.0) .27] 1.08] 2.97/60.4] .005) .317] .049 igilenas a sane ins ese 23] 22.50) 14.09) 18.67/11.3) .75) 3.3) .03) .93) 1.71)84.2) .004| .092) .020 Plankerordrag’. . 2: - ==. --< 13] 2.94) 1.42) 2.30] 6.5) .24] 8. 0} See -1l] .35/45.4) .002) .035! .008 iWieedersst ee sic eo.2222 19} 10.79) 5.76) 8:29) 7.2) |. 70) 6.5)... - 41) 1.11/34.4) .013) .173) .033 Com planters. 2 2255... 2.2 60} 35.45] 18.29) 27.97] 7.8] 2.20] 6.2) .47] 1.40) 4.07/50.1] .020) .299] .081 Cultivator, 1-horse....._.. 12) 4.79) 2.58) 3.81) 8.5) .26) 6.3) .07} .19) .52/12.1) .018) .068) .043 Cultivator, 2 or 3 horse... ..| 102] 24.51} 12.00) 19.04) 7.9] 1.57] 6.3) .34| .95}) 2.86/69.7} .009| .418) .041 Cormi binders 2. 22252242. 2:- 281105. 32} 51.78) 82.79! 6.3] 8.48] 8.0) 1.60) 4.14/14. 26138.5) .199} 2.22 | .369 Cor shocker: 2..22.-22+.5- 6/120. 83) 69. 17,101. 46} 4.0]12.92'10.7| .79} 5.07/18. 78/22.3] .248) 2.78 842 Gram pinder 22203.) 52222. 24/117.11] 46.96} 86.10} 8.6} 8.13] 7.0] 1.10] 4.31/13.54/51.1] .128) .688] .264 Guaimtdrill 2 3 sol 40| 59.69] 35.35) 48.75] 8.7] 2.81] 4.7] .33] 2.44) 5.55/43.0} .018! .397 130 ifeyjlonder 22... 2.8.0.5: 12| 57.75) 30.29) 45.76] 7.9} 3.47| 6.0} .65] 2.89] 7.01/28.3} .130) .488} .248 Mowing machine......._.. 45) 41.64; 21.67) 32.94) 7.8] 2.56] 6.1] .93) 1.65) 5.14/49.1] .040) .558 105 Hiivrake 2asg2 5922322 35] 19.21) 9.86) 15.09) 8.5] 1.11) 5.8} .26] .75) 2.12/38.8) .005) .347) .055 BCG er ae ens cco te. 20) 31.70} 18.60) 25.96} 8.0} 1.63) 5.2} .40} 1.30} 3.73)22.5| .015| .427) .164 Annual cost per machine. Manure spreader .......... 46/112. 25} 82. 93/102. 24) 3.2) 9.30} 8.3] 1.88! 5.11/16.29)....| 7.81 49.38 |16.29 anmine mille ess) LD. 11} 20.81) 13.72) 17.64] 9.3] .76| 3.7|.-.-- - 88) 1.64)....] .41 | 2.53 | 1,64 WS POMMER eames te oS 76| 62.72) 28.26} 46.99/11. 5] 3.00) 4.8} 1.20) 2.35) 6.55)... .] 1.23 |11.21 | 6.55 Comishredder,..2. 2. 222.! 5 474. 30/344. 80'431.14) 3.0/43.17| 9.1] .98/21.56/65.71|... ./37.25 |84.50 165.71 Ensilage cutter..-.---...--: 11/111.04) 71.36) 94.36] 6.3] 6.32] 5.7] .83)] 4.72)11.87]....] 2.21 |36.80 |11.87 Conmnisheller= 23.2222... .- WA) (9574) 5.34) 72 73)11..5|) =38]73.9) 204) 239)" 81). 22.| .22)] 2:26) 80 The wide variation in acre cost of all machinery suggests the neces- sity for considering the acreage per year as an extremely important factor. For instance, 60 corn planters averaged 50.1 acres per year at an acre cost of 8.1 cents; 24, averaging 63 acres, cost between 4 and 8 cents per acre; and 15, averaging 34 acres, cost 10 to 13 cents per acre. This separation of planters into two groups was suggested 212 50 A STUDY OF FARM EQUIPMENT IN OHIO. by the appearance of curves plotted to show the frequency of different acre costs for all the machines. Extremely high costs on a few farms were sufficient to raise the averages considerably above the cost occur- ring most frequently. The curve of planter costs showed two dis- tinct groups, with the average midway between. It is evident that machinery costs should be studied for different acreages, especially since the annual cost of the same machine on different farms varies much less widely than the acre costs. Only 9 out of 130 walking plows cost over 20 cents per acre, and these were excluded from the average. The question of plow costs in the hill section was raised. Twenty plows in this section showed an average of 6.1 cents per acre and a mean of individual costs of 7.2 cents. The first value was $13.20; second value, $6.80; average investment, $10.40; years used, 9.15; annual depreciation, 71 cents; percentage of depreciation, 5.3; acres per year, 26.3. The approxi- mate uniformity of these figures with the average for the whole num- ber was surprising, especially in view of the low percentage of crop area on many farms in this section. The cost shown for cultivators, harrows, rollers, plankers, and weeders is on the basis of 1 acre covered once, or the ‘‘acre-time.”’ Since in the tillage of an acre of land the same implement may be used a varying number of times, the acre-time is considered a more logical unit than the acre. One spring-tooth harrow covering a total of 250 acres per year at 0.7 cent per acre-time and one covering 10 acres per year at 17 cents per acre-time are omitted from the average. The roller operating at 0.4 cent per acre-time was used 300 acre-times per year. Excluding this one, the cost per acre-time was 2.4 cents. About four-fifths of the rollers cost between 0.5 and 5 cents per acre- time. The wooden planker, drag, or float, as it is variously called, is usually homemade, hence the low first cost. Many homemade wooden rollers are also found. Weeders range rather uniformly from 2 to 12 cents per acre-time. One which covered the equivalent of 300 acre-times per year at a cost of 0.3 cent was omitted from the average. No records are at hand as to the acres covered by many of the ma- nure spreaders, and of course the cost of fanning mills, wagons, corn shredders, ensilage cutters, and corn shellers can not well be reduced to an acre basis. Annual costs are given for allsuch. The mean acre cost of 12 spreaders was 87 cents, and the mean cost (or machinery charge) per load for 12 other spreaders was 5.9 cents. It is interest- ing to note that the average years in use for spreaders is much lower than that of most machines. The majority of spreaders in use are probably innovations on the various farms; hence the cost data are more difficult to obtain than those for machines introduced earlier. 212 UNIT COST OF EQUIPMENT. 51 Excluding secondhand implements, the cost per acre-time for 1-horse cultivators ranges from 2.6 to 6.8 cents, with the greater number between 4 and 5 cents. A few 3-horse (double row) culti- vators are included with the 2 horse. Only 3 of the 2 or 3 horse cultivators cost over 13 cents per acre-time. One of these was an extra cultivator, bought secondhand and used on only 15 acres in four years. The cost of use for most of them ranged between 1 and 10 cents per acre-time, 35 out of 102 being a SULKY AND GANG PLOWS. between 2 and 4 cents, ee / (sul ako dave oh. | 24 between 4 and 6 eee call x ee cents, and 12 below 5 2 cents. The acre cost of corn binders varies greatly, but on about half the farms where used it was between 25 and 45 cents per eS eae acre. Two sled har- a EL TWATORS vesters cost less than \ 10°eents per acre. The corn shockers re- ported were used on a much lower acreage Bee than the corn binders, a ais | Esiiss with a much higher acre cost. The wide variation in size and first cost of ensilage av CENTS LER ACRE Var ten GRAIN aaa dans | cutters makes the an average of doubtful value. Two cutters CENTS. cut about 120 tons Fic. 3.—Diagram showing the acre cost of individual plows,harrows, each per year at costs cultivators, cornplanters, and grain drills. of about 7 cents per ton, while another cut about 1,250 tons per year at a cost of 2.9 cents per ton. Three 2-hole corn shellers had a mean cost of $2.01 per year, while seven out of eight 1-hole shellers cost less than 60 cents per year. The shortness of the period of 212 52 A STUDY OF FARM EQUIPMENT IN OHIO. years in use undoubtedly accounts for the remarkably low repair cost of the corn shredders. The cost of 14 grain binders ranged between 15 and 30 centsperacre. Grain drills ranged very uniformly between annual costs of about $1 and $10 and acre costs of 6 to 20 cents. The acre cost of mowing machines varied uniformly between 4 and 18 cents, 35 out of 45 machines being within these limits. The annual cost of 20 out of 35 hayrakes was between $1 and $2.50 The cost of these 20 rakes ranged from 2.4 to 16.8 cents per acre- time, with a mean of 7.3 cents. This is probably a better figure 4 6 DOLLARS. See | [ete | | DOLLARS Ca | tae DOLLARS. ___ Fic. 4.—Diagram showing the annual cost of individual grain drills, manure spreaders, and wagons. m \ . S § Ns . S S AVERAGE &.. than the average (5.5 cents) given in Table XV, in which are included a number of revolving wooden rakes and secondhand steel rakes at a cost of 0.5 to 2.5 cents per acre, and two side-delivery rakes at 17.1 and 29.4 cents, respectively. The cost of 13 out of 20 hay tedders was between 15 and 25 cents per acre. The lowest figure is for a secondhand machine and the highest for a machine tedding an average of 5 acres each year. The lowest annual wagon costs are due to truck or ‘‘handy”’ wagons and to those not purchased new. Sixty per cent of wagon costs are between $4 and $8 per year. 212 SUMMARY. 53 Figures 3 and 4 illustrate diagrammatically the various acre and annual costs for different machines. The height of the points on each curve indicates the number of machines with costs within the range indicated by the figures on the base line. Of walking plows, for instance, 8 cost between 2 and 4 cents per acre, 22 between 4 and 6 cents, and so on. The average cost for the group is shown to be usually higher than those acre or annual costs which are most frequent, owing to the influence of abnormally high costs. Implements with annual costs widely separated from the others, as 1 manure spreader with an annual cost of $49.38 and 3 wagons costing over $11 per year, are not considered. The curves show more clearly than the average the cost of the greater number of machines, but the average is valuable because of the consideration given to the most and least as well as the normally expensive ones. While the lack of numbers makes the data suggestive rather than conclusive, these figures present a fair basis for estimates of the machinery cost of producing crops. SUMMARY. Proper organization, a prerequisite to successful farm manage- ment, refers not only to the cropping system, live-stock management, etc., but to the distribution of capital and the selection of equipment. This study of a number of Ohio farms does not afford sufficient data from which to draw general conclusions, but illustrates by concrete example many of the factors to be taken into consideration in equip- ping farms. Further study along the lines indicated should provide data of great value to the farm manager. This outline of some of the economic problems involved in the equipment of farms is pre- sented as worthy of the attention of students of farm management and of farm economics in general. 212 ‘ =~ ; as | eS tye.) {rie ven andes wl Sena ees eS Aretha ee ieee tai Cee ies horaliedh | Ae Ode Ce Lier én Aeon, 28 i Di PeOey ae A, at), eee AD Et pew ROR, St en> fy iz . a ye" TT Ta el pee Ate foe 2 > *ebo a REIDeS Wo gorda 1 Oa Rt ea ee Co ee ¢ {i con ewteal wi Tatewcen stiri bt perl par ore fae ‘i 4 wien isi We bee vig bt wSuoe arcs: bufin HDS ir tiny ivan ae eee Pal 7. » your. bartn DeOces tas? be a Bite aay, Of o> pen St wT : - es Moi lit Ve at oe im es " TY Uwe. eters i ak : Ln re ue 3 i novell il ee, INDEX. Page Appa U. study of farm equipment in Ohio. 2... ..0.... 4 sedsecancece 8 Barn, basement, distribution of investment on Ohio farms..................-- 31-33 hay, distribution of investment on Ohio farms.....................---- 33 Bees, investment as an enterprise on farms in Ohio.................. 26,27, 28, 45, 47 Beets, myestment for production on Ohio farms..........0..0.5..5....2.265- 26, 46 Perese-rar reneing on farms 1m OWL. 32.52 4264-5 :2g0 jen nie ys ocloe vind ov we 38-39 Brrbya. ©. study of farm equipmentiin Ohioi.2-- .. 2-25 sais sawn cad nae 8 Buildings, hace for estimating values on farms in Ohio-............... 15-16, 17, 35-36 deterioration, as related to total values of ater in Ohin: BINS Pete 14, 47-48 estimates of cost on farms in Ohio............ ee = At Bis farm, distribution of investment in Ohio... 10, ee 17, 19, 20-21, 29- —36, 46 household, distribution of investment on atte? i, OHO! 5-2 2a ee 12,18, 19, 20-21, 24, 29, 46 investment per acre on farms in Ohio..............-......------ 19, 20-21 meas related: to: farms in) O16. sAc.c54s:roahac See heen goles en cio ae 29-35 units of space, as related to farms in Ohio..........-- EERE PAA 31, 35-36 Capital, distribution of investment on Ohio farms............-...-.-.------ 7, 27-28 Cattle, investment as an enterprise on farms in Ohio........... 10, 26, 27, 31, 43, 45, 47 Corn, investment for production on Ohio farms.............-.- 26, 27, 45-46, 49, 51-52 crib. See Granary. Crops, distribution of investment on farms in Ohio.......-. 11, 12, 26, 27, 30, 45-46, 49 Dairying, relation to other enterprises on farms in Ohio............- 10, 25, 28, 32, 45 Drainage, distribution of investment on Ohio farms...... 14, 18, 19, 21, 24, 26, 39-41, 46 Elser, W. L., study of farm equipment in Ohio one Re SR eS Dae 8 Enterprises, distribution of investment on Ohio farms......... 7-8, 10, 16-17, 20, 25-28 See also various separate items; as, Bees, Cattle, Poultry, etc. Equipment, comparison of classes on farms in Ohio.....................2.--- 24-25 enumeration of items on farms in Ohio.................-.------- 28-46 eS beasts OW SATs mE On igp whs5e Ea trace Se ikea oo aM aa 4647 imvesiment per-acneron:farms.in, Ohio. 2.2.2.0 a! velo ens ol 19-25 objects of study, as related to Ohio farms..............4........ 7, 11, 47 relation to study of farm management in Ohio.................--- 7 injiibinyestmentior farms in Ohio- 92222... ..!. oes case nen 18, 24 unit. cost.on the average farmiin Ohio. .... 5: ~-.2s.522$-5206+-25c6 47-53 See also various separate items; as, Buildings, Cattle, Crops, Drainage, etc. Barus, characteriof£ types studied in Ohios. .... 222.2: so ncnosn-- inet Rah TR decay 7 , ; if ’ SP / ¢ fod iE . U.S: DEPARITMENL OF AGRICULTURE. BUREAU OF PLANT INDUSTRY—BULLETIN NO. 218. B. T. GALLOWAY, Chief of Bureau. CROWN-GALL OF PLANTS: ITS CAUSE AND REMEDY, BY ERWIN F. SMITH, Patuotocist In CHARGE OF LABORATORY oF PLANT PATHOLOGY, NELLIE A. BROWN, Screntiric ASSISTANT, AND C. O. TOWNSEND, FrorMERLY PATHOLOGIST IN CHARGE OF SuGArR-Bretr INVESTIGATIONS. IssuED Frsruary 28, 1911. eI TS at, all Boe i i ie ll WASHINGTON: GOVERNMENT PRINTING OFFICE. LOL A. | j BUREAU OF PLANT INDUSTRY. Chief of Bureau, BEVERLY T. GALLOWAY. Assistant Chief of Bureau, WittiAM A. TAYLOR. Editor, J. E. ROCKWELL. Chief Clerk, JAMES E. JONES. LABORATORY OF PLANT PATHOLOGY. SCIENTIFIC STAFF. Erwin F. Smith, Pathologist in Charge. R. E. B. McKenney, Special Agent. Florence Hedges, Assistant Pathologist. A. W. Giampietro, Assistant Physiologist. Nellie A. Brown, Lucia McCulloch, and Mary Katherine Bryan, Scientific Assistants. 213 LA LETTER OF TRANSMITTAL. U. S. DEPARTMENT oF AGRICULTURE, BurEAU OF PLANT INDUSTRY, OFFICE OF THE CHIEF, Washington, D. C., February 6, 1911. Sr: I have the honor to transmit herewith and to recommend for publication as Bulletin No. 213 of the special series of this Bureau the accompanying technical paper by Dr. Erwin F. Smith, Miss Nellie A. Brown, and Dr. C. O. Townsend, entitled ‘‘Crown-Gall of Plants: Its Cause and Remedy.” This paper deals with an infectious disease of fruit trees and many other economic plants which, because of its infectious character, has spread to many parts of the United States. It is known to occur also in Europe and Africa. The importance of this disease is evident from the frequency of appearance of references to it and the amount of literature already published regarding it. Various theories have been advanced as to its cause, many of these by men of high standing in pathological work, but none have been able to establish their theories conclu- sively. The disease has been ascribed to frost injuries, to fungi, to slime molds, and to various small animals found infesting the older galls. By practical orchardists and by most pathologists crown-gall is generally regarded as a dangerous and destructive disease; by some others it has been considered nonparasitic and of little economic importance. The investigations here reported upon have covered a period of six years, during which the nature of the disease has been determined, its cause discovered, and its broadly infectious character established through hundreds of carefully conducted experiments. Its ready communicability by inoculation from plants of one natural family to another is thoroughly established and indicates its importance to the farmer and the horticulturist. As the problems involved are varied and important, with very practical bearing on the production of a wide range of crop plants, it is important that the well-established evidence accumulated in 213 3 4 LETTER OF TRANSMITTAL. these investigations be presented in full. With the cause of the dis- ease once generally accepted as established, the practical questions relating to its control will be much simplified. The illustrations submitted are essential to a proper understanding of the text. Respectfully, Wo. A. Tayior, Acting Chief of Bureau. Hon. JAMES WILSON Secretary of Agriculture. 213 v™ CONTENTS. Earlier studies in the Department of Agriculture.......................------ pimed ewe inthis: bulletin. 22.20.0052. 2. Toto Re ec ee nc enee Discovery of the bacteria, first isolations and inoculations.............-..- Confirmatory inoculations and cross-inoculations................--..------ Eepermenis withthe daisy organism. 2/2126... ke Daisyson daisy. s<-25...- EP SEE OY DA arin aah eran apn| abet Ne ae ARS OTs elO GMI S Sa 5S We eo Ga ae net age ete te Daisy on Japanese chrysanthemum. .................--..------ Daisy on Chrysanthemum coronarium and on Shasta daisy. ...... Baiayormcorna Manigold. 4.22 52.. ioccee os. see eee eae Daisyompyrethrum...2....0.2).222: Ee ye Oe tga GE se) Marsyousl nohinh dgigy sn... Olen cece hence s ca gels eee HU SRI VOTE ISTRY Ns eesti sO. meas 20 cae lar ape eet ae ce a SNOT DOTA acts siesta nels =< S208 Sees pas anc Mees ae Pee era HPI NRO MADOURLORS oral Lakhs i eR gat cep Re cee Wray OURO CGO. 22 lt ke AL 1 es eae pe su eee eA Bareytorolean hensss. 15. aes ie 54 10 Sees gn) ee ee 1 DASNY COL C0) Liyige See Mca Ags MEO sae es an ee a eines MG Perc esi Ne sea Daisy on vegetables (beet, radish, carrot, etc.)..............-..- PisinyonyE ino pean ara pea Nes ay. ee ee ee a ig iusyionrAmercanicrapes.: (352.4. es tae dele Baie oa AGONY ey So As oop! SR eRe cl on gia ee Darsyiomeloversian cy alialiagows 2c se ee a ay ee ae DET METN DOAC RE PINE 810.2 al ie eee at es a eG On JU Us aay eo 121 ONDE eee Rs ee SD RNP atie SeenON lea eet Deiter forms ris CRE yes eet 0d. 6 2 Ae AL et aa pe a 10 SiC a] 10 G2 078) 3 Geka es ep Me De te eeioy7 Ont jae ple wma si Bie ee sh gee gn be Nee RISE OR TOES ty Lak. ty lenis tn Vise RY AA Rr 2) ance Daisy Om various, orchard trees. 1-0 150 S026) oe eee cer ses cee Dae ys OUSGHODAROS Cub ees 2 Ske ea Ces a erga pe na DaleynOmcarn ations: See a TU oe eee ey DSA GUST AT DEB IES sc oA. ld ore oats se he, 3 os ens LUE TEN Noro 110) 0s. ee ne ee ee en ee WENO Mee GEES Yet noe RIES OTN Lieto cB ya arc im hs ele UG, Cem h tie Si es tad ee Daisy, OM CHeStH Ut, sesh BAe FoR NF cet te asl cis) Se raed 1 PuTSh 70) 6.1071 /o- a ey OS ee ee eee ORI R NL UURRm mer en os i Daisy. oneb orsian. walitite 23455. doen o tos nk ye Ss Sey oe Darvon. winced HICKORY. 24: ¢425.2 255 fo ta eich, on seer. te Solse Writ, Onl. SranepOm len. 2 tod) ses css gat toes his eo ade 213 6 CONTENTS. Studies detailed in this bulletin—Continued. Confirmatory inoculations and cross-inoculations—Continued. Experiments with the daisy organisms—Continued. Daisy on ‘Lombardy poplar. =... s.00-dine 22 nee eens ae Daisy on cottonwood ls 3. fio. 1. 25 ee eee ee ee Daisy On GBiIon ... 62.55 ss so es Seabee eee ee ee Experiments with schizomycetes from galls on other plants........... Honeysuckle on daisy. 2.4 3..2.. 6.05 os sere see eee eee ATDUINS GO MAIEY . - oc cce esr sun cen doh eeasee nach bes sa cee een Arbotus‘on sugar beet: + -2--..2-2- 502. se-0ee c5 > Ses aoe ee OCotion 00 GSIBYs 2.22. 5-.- 06.22 222 cheep pee see ogeS een Cotton on cotton. 2). <<. 225 sospee ete bask ees eee Cotton on sugar beet. ...4 2p owe s- ne soci sae- pe eS ee Tape on UdEY . 0 ooo ease cs eke ees s eee oe oe Grape on Opuntia... oo. - ant os ees a ee ne ee ee eee Grape ORSTEPC 3... en oe ooo ae pee ae es eee ee ones oe Grape Gn Almond 625 32 - cee soe pee ae a pe Grape on Giger beet... cn ce cet: aac se obec odes on ee en Aligifa ONIGSISY:.ceiecc os. 2 acta nee ncee eeu ee Alfaisy on alialia 2.23) - che yet ee ge ee ee rr Alialia ion peach @ 2. - 3-2-5. oeccice sae ae cape ones tans ane Alijiia on supar beet. 2.266 sn. eect eee teens hee eos =e Peach on Gay"... =... se ce ee tebe neon ope cece: or Peach On Ole. oos-+ 22 acct len de bencews> aatancess os = = eee Peach on phiox +s -. 2.0.2 0252s 2 eee one ose ee> ee Peach on verbena... 2. 0. 2-220 ee oe ses ee Peach on pape. 2525220022 eee er Peach ‘on Impatiens... 2. .22.2..2 025.202 oso eee Peach on Pelarponium $220.25 22222 cee) eee Peach on peach 200220522 ot en eee Peach on apple .2 202 oo ias foo oie ores - oc Peach on red taspberry..) 2. .22.... 22-2. - 25-225 ee Peach on black raspberry :::2iy2- 255222232. oe Peach on Tosele 2.252 52220 LSS ee Peach on magnolia-. 022222202222 7205- 22 ee er Peach on Peonia. : 2.55.25 i22 StS cee ene Peach ‘on sugar beet:://222222S.c 292222202 22+ ee eee Peach on hop: is: 25. fi25252 22. 2s Peach on red oak...222 552222222 2c02 25522 se nee Peach on Persian walnut.-.2-222242.2-5- oe =e): +e eee eee Peach ‘on Tradescantia- 2.22. 22 ee eee Rose on daisy... 62.22 2322 22242 ses sss ase eee Rose OR TOHO. <2 22.6255. See ee esha eee eee Rose on pedch:..222:522226262222istieet eee eee Rose’on appleg.....2 222222222 22.2nea22 2. eee eee ee Rose’on supar*beet. : 2222222224225) 222 220. ee ee ee Raspberry on @aisy 22.2222 Si 2=s'2.. 25 264 Quince'on daly ......2.5 2522512522252 5222 535-0 ee Quince’on quince... 222222222 25.252 2. a eee Quince‘on sugar beet..2. 2c i 2:22222252 0 2220s se BeetonmMalsy .. 2: 2220.c22522222: 22 A eee Beet on almond... ..22220.525 2 es ISSR Oe eee Beet'on beet... 2.422.855.5052 886s seb ee Se See 213 CONTENTS. % Studies detailed in this bulletin—Continued. Confirmatory inoculations and cross-inoculations—Continued. Experiments with schizomycetes from galls on other plants—Cont’d. page. Additional experiments with sugar beets........---.-..-----..-.- 81 isolation: of MreanisMan i: sd. cuss osese sete beeses ioe s PS, 81 Reinelt/s:experiment =. 4525s veveseees sete POCA 84 Other attempts at isolations. 2 s2:..leiss2 SIA 84 Hop OM dalsyecessestecesisc ek ts seeks ss lerast Yael SR 85 HOPON LOMA Be 24 Jeers eed Samia d oe oI 103 GHEY Teh, OWS AAn DORE. «oe ed. eens so ha Sete ae etre es 103 MSG eEIIE ONAE LG. 55 j-er5 hea acd ae Soe Aas 4 coe a ape Ae AS SP 105 Description of Bacterium tumefaciens from daisy...................-.-------- 105 MorpuolorieqWeharicters.. 55 sseeccisicim -ic.cn cinimineeinin~d ce ee aes Ue 105 MES SialING Celina isthe Nee tebe ce So eile 3 RNS Oe 105 BI ORC Sea fy ayaa aS weary te aS Ls sas ee ec oc ae 106 ME Lite sens ea toned: eee tree AB esc, SMES eines wale oo ze Oe Ree 106 213 CONTENTS. Description of Bacterium tumefaciens from daisy—Continued. Morphological characters—Continued. UOSDSUIGE . < . 4. > «onc. cadet so aua abi 25 438 Sop ee ceOe the ee eee ZOORIOGAG oo won n couse se estates ss2 cy CSOs CORB ORO Es oe Involution forms. 2. - eek ok ce onic s 2 ssa o aoe Bee ee eee eee Behavior towald SAS... 2. <5 neo. os ech amie b ee Bae Cultiiral, characters... 20... ciesrert os sues ss erat yee Cede AUR INWiRUGHE BRAT i - cio s ccase e sae 2 oo oto sae eh oe eRe de ee Corni-meal agar... bens cgsycy.cns ov sete sees ecain eae cee eee Starch Jelly. - -. oon eos ye maces ne's vec oe ee deca b+ oe Se a Nutrient pelatin. oo... sees pine cos see peis eg << tee ea eee Loefiler’s blood serum’: « i.<2 = 2 sds see's oe on cid < cee a ee ee Nutrient beef broth... 2... 2. sep es ended SRR ree nee Alkaline beet broths... 2.0 5-i- occ o-0e oa ssc% 5s <3 eee ee eee Sugsred peptone water....---..-<-.+--.-.+«= a enol ee ee ek n= Se er Usehingky’s solution... . -. - 0. spei ee pee ve a 5 se et bee a ee Sodium chloride bouillon .......2.-..:---.)+5- acts t Saeeeeeeeee Growth in bouillon over.chloroform.........>..,-.-28¢4 22 ane aoe Nitnogen NUUTION.. . 62. 2 ss eencaic <2 sess es dae eEe eee Best media for long continued growth............-.---+---+-eee--e= Quick tests for differential purposes... --..---. «52565 20 tse eee Fermentation tubes...:.--- =... ./o55--2-2-05---eiee See eee Ammonia production. ; ..22--)2--.. Sees eee ee ee Nitrates’ -.....2.2.2.45stsce2 bot ateguh Oo 4c eee So Toleration of sodium bydroxide- dat hsces_5-he eee eace) see eee Optimum reaction for growth in bouillon...............---------+---- Vitality on culture, media... ...-.22-222- ease) 20 Rees Joe eee Temperature relations.......--..-.ase2sueseh)') a) ee 2 Thermal death point. .......-- 2. +. ..- -@0iG8-00 J54bee 20. Optimum temperature... .......2s0.0 32) 0e.0 be 088 se Maximum temperature. ......-. .80sbes. db ee 30. eee Minimum temperature ...-.....= 224: <2: 2. Bee Bffect.of drying. 20-22. .002 4.3202 Dak ol ED ee Eifect of suitlight.! 13. a.2eees0-oatd eG. sel ase 02 2 213 CONTENTS. 9 : Page Observed differences in crown-gall organisms from various sources..........-.- 127, Morphology and behavior toward stains..........-..-.--.-.--------2---- 127 Micthons OF ShUM ye = kes soe ek so eo) eee S 127 LENSES) COE WT ae NORE 2 IM Aen ERE on ae RENEE? Sen Re AR REN ER: Pir Se 128 id: Gaisy....2 2.2 fcaiuet vate do sek ome dee eather cen seed eed sek age 128 PERCHES Se Sh ot of PN NE iy oho se 22 Se ey es pe aa 128 EEO D2 be capa ae tee et oy. Sat et I etek poet & 128 ING WirOSe-= 28a ennai Ae 2 ee te ss ue nie oon ll a eee eee 129 SO iaee gs oe net Neh eect eet oS lc 2 oa 2 eee cael 129 Giidlemple. fis oo5 22) 522 cnt Rs ge Wo Ate ate orotate cela Ber ee 129 BPE airy TOOt ora hk oy eet ets ait aire Ice Ames te ehos 129 PMSA PNG os coe tiec Fo he 8 Oe eel hs ei Beth ae yh oe lh eri ete 129 PAMPER ES se Bk oo pe ae ng eC ie Eigen at len aa SN VAN las tie beeen adage 129 RTD cos als a ah ain 2, ape 2 nokta 2, = 2) aye ee eGo ae es ese Oa aus oR 130 Nee Clestait 2 2). ae os appz es hae aes at rd Awe peck ee ig penn 130 PACT THOMSEN OCO: an eee ne eae Specge pa eRe oe e sl nyt at) ns an Ll 130 SO OREOT cot Bre) 8 ea hs Sah ol so Siete ee Teint oats 130 CUT C O92 oo te het Se ape eS Syne res geet yells Bylot 5. Ss pce 130 SILL] 113 oe eee eee er nenn ee cie S Serer a s aeeNr ire ceee = hey se | Le ee 131 Pinllow:- trom: South Atrieg.21:4.9 oh} juft Now ctietay deus ke eee 131 LESS Daa (2 Ay 22) i er eer enn nes eM Strep tt Ae 131 aman (NEW PON) ao. < 2 en ans Goo ee eR eyes eee tte Ceres 131 pt NO. os 5 oA ot Siok bs acl cecls gaa anes aati tase aed 132 _ SEER CML SA eee ee ey are 9 SENSE ee Nc 2S Te 132 SASL NR a a a Oe ENTS CHEAPER EPIC AmeS Steet oe LY) Tie 132 PUTA A tcc hd Sesser Spe 2d seis $3 ee meley oD Jeo hee ees 132 Gapulated results of inoculations. «*~ ..:.0) «24-2: osexnni ele J-et see 3 ie 133 AG IMMUIPAEG WATACHEES 52-522 Soci oe ncke Saye en, at SR Cope en ee ae ee aa 140 Pisapr LOL BEALCINON ois no Ses teoie cyeS a ee rae Se ee 140 S00) La a aes nee geared ts Se ee pea we Moraes Pe 140 Growth in + 15 beef bouillon with 1 per cent Witte’s peptone.........-. 141 de Saar PEDLONG WALT. 2.2 ot once 8 ea eae oe = EES Aes 141 Meanese peptone Water... .....625,445%4) ees ae cosa eaae ose eee oe 142 Acid and alkaline bouillon—Table IV and Table V....-..-.......---- 148, 144 Bouillon with sodium chloride—Table VI........-- RS RENE es et 144 eins OLghion— Dable-Wil 2.8 ot. ac 22 oe 38 Ss ee on alan SE ee 145 Sbanchie) eliliv— Dab ler VAM ie, sei fer ne ae Saath en este) Uae a SS et ee 146 Pisielresction—— Tapio Ve ce oe ee os eb betes dee ema ae oo 147 epinetonNGl Mitrtleda os | Soc oe ss ne cue ee ok oe reg 148 Pe MMIGArY. SLALCINEIO: 28 22/5 'cie/o5. 5 4 4.3he,s areas sine ot ee 148 Brey ee ese ae io pk nah ay eel eh Relat ey are 148 eae hes ois oi rs Seite eee SEG IEE eee hee eRe ea Seo eee 148 BU aia soho Sie ls te ms oe CaN eg Se atle eAii. ete hat Js ae 149 OO sg hs ote tS aa ae ac ote Be Be er haan eh gale 149 BIG oof eae ara ier a2 ic a eee poe pred 27.9 TS a Re See 150 maple haity-T00t 2220. te oo ------0-- ------ 2 eee 188 The rose. 5. 2. 2. eee DE oe 189 The Grapes 258 oe aw seed Pe eee een = eee 190 Red-elover aa: eee we eS Ree ee 191 UIC E SSeS Se Sane Sat AOR ISOS Aas Sc 2 191 Cotton: Posse See eee 2 Le eee teee tee eect eRe ee 191 Hops s2es2ttole: Seeet o.22¢ = eee eet chee tes SE ee 191 Supar'becta-¢2022t2--eeee. o- ees ee ee een 191 Tuberculosis of beets. ....222:.2¢.5-22-52+- se 2h ee 194 Description of Bacterium beticolum n. sp ........-..---------- 194 Shrubs; shade trees, and forest trees... =~: -.2202++ S222. eee 195 Hothouse plasia:ss.2-2- 2. 52. 222 e ces et eee eee eee 196 Best method of dealing with the disease: .-......-+- 2.24 .-+7422222 552 -seeeee 196 Synopsis of conclusions respecting crown gall. ..........-------------------- 197 Jndex.2-Jiccde ceo S CRE IR ws wet cee ck be Lee Ge eee See eee 203 213 —— Pruate I. TH: ITk: TV: XIII. LV. XV. XVI. XVII. XVIII. XIX. 213 FE BW SekeAvLONS. PLATES. Fig. 1.—Daisy on daisy; three needle pricks on each branch; time, 2 months 10 days; natural size. Fig. 2.—Daisy on daisy; time, 7months; three-fourths natural sizes) 2.222222 See A eet Fig. 1.—Peach on rose. Fig. 2.—Apple on apple; galls-at X, X. Fig. 3.—Hop on tomato. Fig. 4.—Chestnut on sugar beet. Fig. 5.—A and B, daisy on potato. Fig. 6.—Rose on sugar beet... -- Top.—At right, B and D, daisy on oleander; at left, natural gall on oleander from California. Bottom.—Hard gall of apple on daisy. Fig. 1.—Nematode gall on sugar beet, from Chino, Cal., 1909. Fig. Daisy onred radish j)' 222 595 Nea ees 2 2S tyes =e sarees = . Fig. 1.—Daisy on grape. Fig. 2.—Daisy on gray poplar..... eee . Fig. 1.—Daisy on peach, at end of 10 months; about two-thirds natural size. Fig. 2.—Peach on sugar beet, at end of 37 days... . . Fig. 1.—Daisy on carnation. Fig. 2.—Rose on daisy. Fig. 3.— listinton Sugar beater.) ctee ence tee oe ete teen eee . Daisy on sugar beet, at end of 4 months; both plants from same BOrICS Ajay seca oe ae Meee . Fig. 1.—Daisy on hop. Fig. 2.—Daisy on cut surface of raw turnip in covered Petri dish, in laboratory. Fig.3.—Grape on almond .. . Fig. 1.—Grape on grape. Fig. 2.—Grape on daisy. Fig. 3—Grape on daisy; from same series as Fig. 2, but 3 months later -........ . Fig. 1—Peach on peach. Fig. 2—Daisy on peach. Fig. 3.— Peach: om peach (another series) s24s242.2¢ ui: Jo. AGS Pee g . Fig. 1—Hop on sugar beet, at end of 31 days. Fig. 2.—Peach on apple. (hard.sall),atcend of 2 yearsie-2n0 ss ccnek cnn vac noe ee eee Peach on daisy. Fig. 1—At end of 5 months 12 days. Fig. 2.— At end of 4 months (second time through peach) ............-.-- Peach on geranium (Pelargonium), at end of 3 months; slightly MmnGerpnatural sine. ne St tle. ray par aie! i ated ara y fel a aaa ees Fig. 1.—Apple on daisy, at end of 10 months. Fig. 2—Hop on almond (one gall on crown; one on stem above crown)...---.---- Fig. 1.—Chestnut on daisy; less than natural size. Fig. 2.—a, Alfalfa on alfalfa; 6, ordinary nitrogen-fixing nodules of alfalfa, ibroducediioneomparisons* 4235 9.2522 22ee aan fescie erosions Hairy-root of apple on sugar beet. Figs. 1 and 2.—From one series of inoculations. Fig. 3.—From another series .........-----.-- Apple hairy-root on young apple trees. Fig. 1.—Hard gall at X. Fig. 2.—Typical fleshy roots at right of X; both photographed MOn AMON INVAICOMO!. oe tess en scire, 2.22 Felon ale sant oe Sane Page. 201 201 12 PLATE XX. XXI. Xo: OG ANE DOGG XEXCVE: DOWAE XEXGVills XXVIII. EXEXGIEKS Xe XOXDGT EXOXE NTT *:O.@.G 008 XXXIV. XXXV XXXVI ILLUSTRATIONS. Fig. 1.—Nematode galls on Stizolobium. Fig. 2.—Natural crown- PR GRPOGE 23 oo we Coke deh eit ok ioe seein eetaee a en een Hop on. sugar beet. ..<:.2/2tei.~ cose b- deve eoee eee eae aan A.—Daisy on salsify. B, C.—Poplar on sugar beet -.............. Crown-gall on white poplar from Newport, R. I...........-....-- A.—Arbutus on sugar beet. B.—Grape on sugar beet: C. lar on grape Cultural characters: Colonies and streak on agar, growth in milk. . A.—Photomicrograph of incipient tumor on rib of daisy leaf. 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(fe Se trae es age ODF so S061 ‘IT “Iewy “@SBISIP Pe}IV1}UOD OSTR SYOTO osnvdeq pooalexy [L0¢ ; DITO Sima ae xOeN ponies sles -' scene OLUGRLO Ia barnes aces pata OD Esa at 8061 ‘ez “URE “JUBULIOP Sool, | 0 Di [eS CuSiBoes tha se ees gaa tne es Gy (KON ef Seer are TOD ao g° Yovedg | SO6I ‘OL “ues “yeo] 0} SuyuuyZeq ere soony, | 0 9 [ttre joy ee tofal nt hye lemmas ieten ee g c Oued py jo eee aeeeeeietocs aes ee hy ae SONMIDUOOMOOUGURSIUGIaNin0) salamat s QS/ae sess UNO Kes | ae a BIBILANDLONRTOAGS) | se ae eertiass oie Sas ce = (0) Os 6061 ‘8 ‘oaq “syuvld Plo PSN ane P AV Ee | [ld eae | Pc na a lle aes oe WOO s[OOMUGS Win |e ine (SlOOTIQ) Byes |. a se BIVILV | 6061 ‘OT eung *ASTBp pus edeiz uo [nyssadons Ayjeyjsed ela. SeIngINOaWIBVG | Oe ie pa(uch hie SES SSCS Ion SSS! HX }sYo[crdcts) 1syh Se ema eran oat ca i ota IT op*"*"*| 6061‘ Tg “snW x) ey Pa peeestieiers Ok mane ees we OVE SMSC oy Use (4s Ail lang a aaiataeanoicn rss CA AES) (2) OTOY i aaa ND aR agen ie “Op"-*""| S06T‘8z “IBV SUIS GIO AULA QOGUSHIG IN, «liso eae eek wpe a uke pees DB ZesC Ti Seka diye || 5 Sie sole Clsistecs aah jOROKONUAT (ceL oh ela ote aac ee Ose StC aedeiy | S061‘'2z ‘IeW MATAOIS ANGACMOISSIUG TINO 9 |i e rene aS TABATA SS Sao rs Dyes CN Baa; || ees os eee ai TeTal eich AMkSH(O)e || thease mae a ao Opes as or6t‘s Ang LY geet” + ROG ean Ie forse SSD ae CMLSKOR [ore ola sisi se as IASI DM ecotte acer some aicteee 1103400 | O161‘6z Ady ek podo ; é = 3 poye]noour : woIRNoout SYIVUIOIT | oeeD 928 S}I pue pesn o1Ng[Nd Jo pursy sued jo pury pue soquiny 91N}{Nd jo VIZIO ayy Jo eq yuo 19g ‘ponutju0)—suoypynoour fo syynsad [nfiqnop Lo avynbau buimoyg— TI] AIAV, irl — | 139 RESULTS OF INOCULATIONS, , ‘eg ‘d syieured 998 ‘Sainjiey [RUONLppe 104q v “{X0] 009 OSs ale atte Se Ue oe PG “qns IBsVy te i, yd oo As OUVBULOIs OTS | \teaue so tomate come ae neon aren (0) 0 ae ! 6061 aT ‘dy *(sjueld rosun04 | Oe SS We wap eee Ge Se ae oe IC} oa yon BiaAeVs) oO fe (80 0 Pal (eta ae OD SO a (ay oc S061 ‘OL “0c *(somny sS{OOT T1895, DO Pele[NoouyT {WAOIs [IME Sime 0) “yp iit :wesvuen thi bust usec us pe “qns rsy | -ound so sdnoiz 9¢) 0eUI0} g |***- joor-Arey ‘addy | S061 ‘TZ “AON “Topnitup we Aldor »,;,400TOUdIO;Y, 9008) ||\OF © s|pru@acusbctsc unas beet tua. CS ite.o Go OO ye | caer eee lee HOO(MIUSNS OL | o> ee ee ee eidde pio |--"""*" od CYA Rape me PR i es a a 2°" Dnata =| aes aed” uinyuosivjod OT Opa aes OL6l ‘Fo ounr *SJOOI UI8}S PodojoAep-[[aM UO peyejnoouy | QO pz “qns sy |----oyeur07 jo sjuvld [etaaeg |-~- (paey) addy | go6l‘F “ood 0 “lpg stain oleic File SSI SSI 0} 8) BIOISMOW TO SOT GOOMO) "ss ee ome oa (0) oases a od “ATOLIO PPA EGA SUICG allie 0 ill Gamestop amos Sat ee nas ime = OD" See dikes ot Rae ee SO OSC TBO LIS Giy| os 2 eu CPS Seen OD lee od “s[[e3 Avs Sostep {ATMOS ATOA BUTMOIS SOOLT, | 0 SSD Ghes[OONTUS ile ee ae os eae a Sf) (0 C03 Si fae ep OOS ST Op"*"~"| S061 ‘ZI “AON “OSCORTP PalOBALUCOSOISIEGL.|.0L, | lessen wou ce oss aes SDC TOO aU le es oe ea “uinyjuosiejed g |-"""-""*"" eMoy ‘(prey) sjddy | S061‘6 “AON *suypeoeid se sojeid jo Jas oures Woy UISJUeBIQ | Q tte SDP ecTsnteaW, Ils oeae toe sce ma eee Us) (kof pig |e pi Sr sicher edieie ns OD re cee| oe OCT 213 140 CROWN-GALL OF PLANTS. CULTURAL CHARACTERS. EXPLANATORY STATEMENT. Such comparative studies as we have been able to make are included in the following tables and memoranda. Many of them were made or repeated in the spring and summer of 1910 during the preparation of this bulletin. In offering these incomplete data it may be pointed out that prob- ably some errors have slipped into these records, as the time was not sufficient for exhaustive tests of all the cultural characteristics of all these strains and for the elimination of all possible intruders through repeated poured plate separations and further inoculations. It is the more likely that some errors are included owing to the fact that in 1910 a number of our forms had ceased to be pathogenic, e. g., peach, chestnut, apple, quince; but whether this was due only to loss of a peculiar quality, or to the right organisms having been driven out of our cultures by unobserved intruders was not determined beyond all doubt, except that clearly the ‘‘old apple” appeared to be something entirely different from what we had on the start, and very probably the quince and the sugar beet. To straighten out fully all the tangle of interrelations here touched upon would require so many additional months of work that it has appeared best to publish at once what we have, leaving the unsettled problems for further study. GROWTH ON AGAR. When these organisms were grown for 3 days at 23° to 25° C. upon slant +15 peptonized beef agar containing 1 per cent agar flour, and inoculated by needle stroke from 18-day-old slant agar cultures, there was in each case a well-developed shining white streak and some growth in the condensation water. The agar wasnotstained. Slight differences not easily definable were visible, the most pronounced of which were the following: (1) White watery translucent streaks: Newest daisy, arbutus, new apple, apple hairy root, new chestnut, grape, alfalfa (the last showing transitions to 2). There were no crystals, or only a trace (new apple). (2) Similar streaks but whiter, i. e., less translucent: Old daisy, peach, hop, old rose, new rose, beet, cotton. Numerous prismatic crystals, except in beet which had only a few. (3) White shining flat growth, i. e., thinner than in the preceding and trace of crystals: Old apple. The growth of this when first isolated (2 years ago) was like No. 1, i. e., translucent watery. (See under Morphology, p. 129.) 213 ‘ CHARACTERS OF GALL ORGANISMS FROM OTHER SOURCES. 14] (4) A thin white growth inclined to wrinkle, crystals few and large: Quince. This is the only culture showing any wrinkles. This experiment was repeated in July, 1910, at a higher temperature (30° to 31° C.), inoculating from younger cultures (1 to 3 day agar), with less typical growth (in some cases colony wise) but nevertheless with essentially the same results. Under group 2 fewer with crystals. The old apple looks decidedly unlike the others and is probably an intruder. GROWTH IN +15 BEEF BOUILLON WITH 1 PER CENT WITTE’S PEPTONE. At the end of 3 days at 23° to 25° C., inoculating from slant agar cultures 18 days old, the appearances in test tubes containing 10 c. c. of the fluid were as follows: (1) Incomplete easily fragmenting pellicle, fluid nearly clear, stringy threads on shaking: Arbutus, alfalfa, newest daisy. (2) Cloudier and with a heavier pellicle but otherwise like 1: New rose, old rose, cotton, hop, old daisy (B), peach. (3) Cloudy and more or less stringy but destitute of pellicle, some precipitate: New apple, old apple, apple hairy-root, beet. (4) Cloudy with some flocks, but no pellicle or strings: Quince.% This experiment was repeated in July, 1910, at 30° to 31° C., inoculating from 3-day-old bouillon cultures. The results at the end of 3 days were the same, except that now the newest daisy had no pellicle, and the old rose an easily fragmenting pellicle. The previ- ously untried strains fell into the above-named groups as follows: Group 1.—Newport poplar No. 1, salsify. Group 2.—Turnip No. 1. Group 3.—Grape, Newport poplar No. 2. Group 4.—New chestnut, willow. The parsnip did not resemble the others. It was heavily and uni- formly clouded with a precipitate which rose in a swirl on shaking. There were no strings, rim, or pellicle. CANE-SUGAR PEPTONE WATER. When grown for 18 days in river water containing 2 per cent Witte’s peptone and 2 per cent c. p. cane sugar the strains did not brown the fluid, but behaved as follows: (1) Fluid clear and not much precipitate or flocculence, but a very copious thick white pellicle (0.5 to 1.5 em. thick, mostly the latter): Alfalfa, turnip No. 1, Flats poplar, new rose (pellicle 0.5 em.) cotton, hop, peach, old daisy, newest daisy. a The old chestnut was discarded as contaminated, and the grape did not grow. 213 142 CROWN-GALL OF PLANTS. (2) Fluid feebly clouded, some strings and flocks, pellicle incom- plete, thin, fragmenting, not much precipitate: Salsify, parsnip, arbutus, grape, apple hairy-root, new apple, Newport poplar No. 1. (3) Thin cloudy, no rim, no pellicle, but a precipitate which makes the fluid cloudy on shaking: Beet. (4) Trace of rim, no pellicle, no strings, moderate clouding, slight precipitate: Willow. (5) Moderately cloudy, trace of rim, no pellicle, quite cloudy on shaking, but not much flocculence, and no strings: New chestnut. (5a) Moderate white rim and very scanty pellicle, quite cloudy with much coarse flocculence on shaking, but no strings: Newport poplar No. 2. (6) Fluid clear, no rim, no pellicle, no strings, or filaments; thinly clouded on shaking by a great number of fine pseudozoogloee: Old apple. (7) Like 6, but clouds on shaking with a finer precipitate: Quince. At the end of a month the tubes still fell into the old groups and none of the fluids were brown stained. When tested with neutral litmus paper the cultures gave the following reactions: Group 1.—All strongly alkaline except alfalfa (slightly alkaline) and newest daisy (neutral or slightly acid). Group 2.—Much less growth: New apple (slightly acid); apple hairy-root and arbutus (neutral); grape (alkaline); Newport poplar No. 1 (alkaline); parsnip (alkaline); salsify (neutral). Group 3.—Beet (strongly alkaline). Group 4.—Willow (strongly alkaline). Group 5.—New chestnut (slightly alkaline). , Group 5a.—Newport poplar No. 2 (strongly alkaline). Group 6.—Old apple (2 tubes, plainly acid). Group 7.—Quince (2 tubes, alkaline). Only groups 1 and 2 contained organisms of recently proved virulence. Subsequently the willow was proved to be pathogenic to willow. MALTOSE PEPTONE WATER. When grown for 3 months in river water containing 2 per cent Witte’s peptone and 1 per cent maltose the strains behaved as follows: (1) Fluid clear, unstained, slight stringy rim, moderate flocculent precipitate which clouds fluid on shaking: Newest daisy (neutral to litmus), alfalfa (strongly alkaline), arbutus (acid to litmus), apple hairy-root (strongly alkaline). (2) Like 1, but fluid brownish and alkaline: Grape. (3) Clear unstained fluid strongly alkaline to litmus, pellicle 0.5 cm. thick, slight precipitate: New rose. 213 CHARACTERS OF GALL ORGANISMS FROM OTHER SOURCES. 143 (4) Fluid dried out one-third. Dense white slimy pellicle nearly filling the remainder of the fluid, i. e., 2 cm. deep, not much precipi- tate, fluid alkaline: Old daisy, hop. (5) Exactly like the preceding except that fluid and pellicle are slightly brownish, fluid alkaline: Peach, cotton. (6) Thinly clouded, no rim, or pellicle, fluid unstained, a moderate precipitate which shakes up in a coarse flocculence, which is most abundant in the beet: Old apple (acid to neutral litmus paper), beet (strongly alkaline), old chestnut (neutral to litmus). (7) Fluid moderately cloudy and yellowish (alkaline to litmus), rim yellowish white, not stringy, no pellicle, moderate precipitate which shakes up in coarse flocculence: Quince. TaBLE 1V.—Showing behavior® of crown-gall organisms in peptonized beef bouillon of varying grades of alkalinity or acidity. [Inoculated from 3-day-old and 7-day-old peptonized bouillon cultures, except —25, which was from 19-day-old beef bouillon. Examined at end of 28 or 31 days, except —25, which was 9 days old. The +34 was acidulated with citric acid, the +38 with malic; the alkali was sodium hydroxide.] Titration (grade of alkalinity or acidity). Organism. —34 —25 —24 Newest daisy.-.....-....- OPO Ns ssceccnsceteececee ONO Oeeee coe see seers ce Bush eH OGY RISA a capcie cose mies IE Hie Sate alee Sata RETEIAS SYGIOE o. Sa ea aoe Rae ee cee 36. J2GhCl tl A ae ae eee Db OE OCE RGA HORUS et IO En GE dear e SECS SCE eet Ee 3b IO Deee ees. 52+. oes CER aee acre ae EIENE coe EUs Ue eee eee 4 Ragged pellicle. INGWETOSome ss cece. ee OR eee see Seon sete 2 Thin pellicle.........- 3 Good pellicle. re Soy cS. ane ae ee Queer eee Se ee Osa ocamentss sanaeeee sinc 0. pple hairy-root ........- Qe relosee sate erie Wine net ic ocobsenodoccedeare 0. MMA ems eee sah. shox, Oe ao aoeeaas seigeteceoee tS tS Seva aeraSas intel tette sa 5 0. Grapes sees c- tssee es ere eee eee eee Wong eee sseecceers wae 0. (61: (G5) 0710 | See ee eee OS Scere serio ee sese ae 3 Uniformly cloudy. | 3 Uniformly cloudy Cont.? Cont.? ADIL S resco cece ae 2 Qhaes 2 sae eeme se acon ass Ob gets esas tens caine Sune 0. Wontone cranes ccs sccceccs Daa eee te oe poems ae 3. Thin pellicle... ....-:- 3. (SN thG Copy ae ee ee De sein states Ate HERE ac PASO ae ote Oe BOSE 0. IBeC bee iscas- aeseceses- Oeste eee sack see ce Pe ae ener aoe 2 or 3. Titration (grade of alkalinity or acidity). Organism. = soles te —16 +34 +38 Newest daisy..........-.- Do25s Se eeee eases ds 3 Thin firm pellicle; | 0. clear fluid. Oldtdaisy= e- a-22225--2- = 31D), SaBaaas Paes ose One eeceaue : .| 46 Clear fluid. Reng ieem eae ort i ok 40. . eRe rae een sctee Hoe sa sem ee .| 56 Fluid cloudy. 1200-2) eee eee 4 Ragged pellicle......-. 5 DB ee coe sks .| 58. INGWELOSC ss cacc 28.2 5cn2- 5 3 Ragged pellicle......-. (URS eect acta Bote aa eee 0. Oldfapples- 22 .2-22222¢ OL. s 5- A pecatseie te tee ssscee 3 Cunennly cloudy. | 4 Rim and cloudy fluid. ont. Apple hairy-root .......-. Qe see eee eee aaa se SEO aoe Seer = eho asi cisnere 0. VANE | CE SSO Se eee eae Quai ocian ae osteo ees 3 White rim with precip.| 0. Grapenn eee. 2 sc---'=5 +25 USS eer Se Set On eee nes Se Siam ole. ao Uae eee 2 Strings and feeblecloud- ing. Chesimuts: a --.2-32-s..2- 3. Uniormlyy cloudy snl Ol-eee so ser o-- ees an cs : Cont.? Vtg 9) UEC See eee ee Oise eames oe ee ae eons 2 Thin white rim........ 0. (Ol Ao cline — Seer ee 4 Fragmenting pellicle...) 5 Fragmenting pellicle...| 5 Heavy pellicle, break- ing on hard shaking. CUNCT HES Saree ene ee Quine feeateniesen dae eee (oe Bt eicioc= CaeOs mec ren eee | 0. BeGhisernn as oes cerocita ce 3 wwtrines!) precipitate Oneessccettcn scene ce. 0. pale salmon. a Explanation of figures indicating growth: 0=no growth; 1=trace; 2=slight; 3=moderate; 4=good; 5= copious. 6 Thick firm pellicle, not broken by shaking. 213 144 CROWN-GALL OF PLANTS. Some additional tests were made in 1910 in acid and alkaline pep- tonized beef bouillon with the results shown in Table VY. TaBLE V.—Showing behavior of crown-gall organisms in bouillons of varying reaction, the records being taken some weeks after inoculation. [The alkali was sodium hydrate.] 7 sy ss fee tier, itration (grade of alkalinity or acidity) (The first four strains are of most recently estab- | ——_ —————— — lished virulence. ) —29 | —25 | —23 | +36 (citric acid). | +34 (malic acid). LOU Shrove) oJ E\ gaa eae ee } 0 4 2 4 4 Hop. F ‘ ees SS Serge Pia pe oe es Ee ; A secekalows sewbsbeots cess el aun cete ane TET] 2s eee Se oe SR ee ae yt (Sree Peach LAR ss See eee es ee ee ee aE cE 4 A). occceo kk he ee i pee CUTS het] Hee at MIOE SE e 95 O8 Atne pene e fae is) (agp 0 0 0 BD Nee te ee eee. Ot RI epee 4 | i22.. 560. ele eee Croceee ns ed PO Nes ae a ee en ee) mene | bee 0 4 4 ATigiiges See See. Stes See ec secs t ee eee! Em cee 4 4 4 Qalinga Fe ses nas nate eee ede ae oa cana n lan eee Pee 2or0 0 0 De eee ae ene Soe ae ee a Paes eee 4 0 0 (ATIEUIS oe oo aa Oe eene = oe ene en cehae eae neeal ness eeear 2or0 0 0 ING@W. LOSE © oOo. be sete ee een am oo een ene eben saa 0 0 a Explanation of figures indicating growth: 0=no growth; 2=slight; 4—good, with pellicle. TaBLeE VI.—Showing behavior % of crown-gall organisms in +15 bouillon containing sodium chloride at room temperatures. {Transfers from 5-day-old bouillon cultures.] Time (days). | Time (days). Organism. Se Si al Organism. Ave | Ab.) oh, Bets 4. 15 31. | | Daisy: > || Grape a OIPSHCORU- ce eee cece sass 0) 0 | 0 30) Per CORL. 2-6 e-- eae ae ae 0 0 So PEDRON Toa. = aoe ae 0 0 0 325 PELiCeRt: oss toes 0 0 0 4. 0 PECONbe seen eee 0 0 0 40 DGE COM. te eae eee 0 0 1k | New chesnut: 3.0 POE CON cee es owen eae 2) 3 3 3.0 per cent... 2. 2-222 eh Bese SS ETI CEI Ls ae Soe eee ee 0 0.\% 40 3.5 per.celibsoossecb.. cee eee rl ees PE iis c= 1 | eames 0 0| oO 40 Por Celit.- 52. ..-2k ee oT. Hop: } Old chestnut: Sp UIT oS Cr sang sap Sea ee 2 5) 5 3.0 per Cont. = eee 0 0 2 SOIpORCOR bees cerns eee ee 2 210 42 3:5\pel Cent sss sceeesaaee ee 0 0 0 4. O;pericont.o- =e. Sane ee 0 0; oO 4,0 per-eent.*.— 222+ seen 0 0 0 Arbutus: 3.0 DCE CONUS eee eee 2 | 5 | 5 3:0 Per CON o ~~ oc ae 1D ee 0 3.5 per Contec - see 08) 1051 Geto 335 POr CONG Se seat cee ON 0 20 Per CONt=— eee 0) 0 0 ZO periCOntcesn.- oases Oe 0 Apple: | | Cotton: ¢ Old strain— { 3:0; por Conte oe 2 sees 2 5 5 SO per centers. sos shee =f (oa as 3.5 per cenb..- 2222 sseess205 1 1 1 3.5 per cent..-.-.....-.. 4 5 5 40 per cent 2— =. .-23 sass 0 0 0 4.0 percent. ---.------- = eee. 5 5 || Beet: New strain— 3:0 percent? 22-525 5ss.ss2—5 A ee Se 5 3.0 per cent...-.-.-.....- 0 0 0 3.0 per CONS aes tose ee 3 eeetoe 4 3.5 per cent..-.-..-..... 0 | 0 0 “Oper ieconts= 23522 saa Pi eens 4 ADper Cente cs cnen-c oe 0 0 0 || Quince: Apple hairy-root 3:0 pericenbs> ous. 3. see 0 0 0 3.0 percent. .--"---- ~~~ = 0; oO 0 3.5 per Cent. -------_------. ) 0 0 B.D POnCON User eee pe ee renee 0) 40 0 4.0 penicent.* <> oes aoe aoee 0 0 0 4.0 Pericentzsoceeene cece = =e 0 0 0 || Flats, poplar: Alfalfa: 3.0\ per cents<=2%- 2-2 22.22 esiteees O e225 30 Pel Cente ss e- e eee 0 0 0 3:5 Per Cents: . 5. 235225252) ee Bee 3:D) Per Celtss oe eee eras Ee 0 0 0 4.0 per Cent ....2.s.ei55 2-552 <0+|soreee| soe eee 4.0 per Contes pases scence ee 0 0 0 a aa of figures indicating growth: 0=no growth; 1=very slight; 2=slight; 3=fairly good. 5= heavy a repent of daisy there was moderate growth at end of six weeks in 3 and 3.5 Pi cent. ae a repetition of cotton there was no growth at end of three days and at end of fifteen days; at end of forty days the growth was 3, 3, and 0, respectively, for 3, 3.5, and 4 per cent. 213 CHARACTERS OF GALL ORGANISMS FROM OTHER SOURCES. 145 TaBLe VII.—Showing behavior® of crown-gall organisms in Cohn’s solution at room temperature (20° to 30° C.). [Transfers from 4-day-old cultures.] Date of examination. 6 3 days. |1 week. |13 days.|2 weeks.|24 days. g Organism. sBOn EES: Remarks. sg 3 3S sg =| 3s 5 5 = z e = S zg 2 ba 2 2 o ie) eo) o io) ie) Daisy scees ees! | 0 | OF keer Oe eeortel aecearets THD Nd S38 ea 0 PAN) Sa ee PAS ae wh 4 | Cloudy; numerous flocks. 12 0) 0)) Seco nae 0 | 7 Rennes Dee ae a 4 tent clouding; stringy precipi- ate. ROSE assess sce don 0 Dilan be ere Pe | apne es 4 | Many flaky strings. Uy) Cee ee 0 (pl Seen a OL Sees 0?} No clouding; some small fine flocks. Apple hairy-root..-- 0 il ets Ae 3 a bse 4 | Milky cloudy; membranous pre- cipitate visible on shaking. + (CL ee 0 US) eerie UA ees 3 | Cloudy; some flocks. (Gina O reise a cis =o 0 aol ese UM = Cea oo 4] Cloudy flocculent; clumps of branched crystals. INGWAGHESTE Use ~/2<|= 2522.5 lac scoot (CO) Ee ee eee ess ee Old chestnut. .....- 0 2h Se eee vr neers 3 | Milky cloudy; no flocks or pre- cipitate. / Nii 0)04 5 a 0 OES COs leh vsctel (0) jie ae IDeiteese ss so sti < 0 Oh) Paaeesee (Ug) be Ss el be (COGRO Heres nse - = | 0 Ou) keen eee: 0 ONE @uimeess 2222 2 0 PM eye te 7h | Reiners | 5 | Yellowish stain. Flats poplar......-- Soe ee ona COUN SE Bares Master MS enter | a Explanation of figures indicating growth: 0=no growth; 1=very slight; 2=slight; 3=fairly good; 4= good; 5=heavy. 6 Stringy growth. c One tube milky cloudy; one tube clear. d Two tubes, no growth; the same stock grew in nitrate bouillon. 78026°—Bull. 213—11——10 146 CROWN-GALL OF PLANTS. TaBLeE VIII.—Showing behavior 4 of crown-gall organisms on starch jelly at room temperature. [ Transfers from 5-day-old agar cultures.] First test. Repetition. n B | al 11 days. 8 days. 34days. Organism. pas | als 4 s ears Remarks. & |Remarks.| 2 Remarks. - ~ ~ = co I<) So <] aay Id’strains-..-- 5| 5] Color unchanged..|} 3 (>) 3 (c) INOWOSE Straits si 50201 olen sae ec unite cons ee 1 (@) 1 (©) Peach: | Old strain.-...-. 5] 5] Light brown...... 3 (>) 3 (¢) Another strain-.| 5{| 5 | Color unchanged..|....)..........]---- Hep Re sep mE ON eae 5| 5] Medium gray__._-. 3 (/) 3 | No diastasic action; no brown stain. ose: Old strain...... 5| 5|Medium light] 3 () 3 (c) brown. ING@W SiTainc.oc-|- ee) dae culture). copiously, After | After | bee’ (examined 24 days.|69 days.| bouil- 43d day). lon). aisy: (CNG! Siig ee ee r ee eee Te See cen oe aoe ee 2 2/3 WWeWeStrescntj.ceccseced< 2a Dehya nyfallen!| Cs eee | 2 22 2 (?) c2 pellicle; does not break up easily. heaeheemeecceeeee stat she MOTH SS 5 rags Re SES 2% Be 5) 2 3 4 IEG Ses oe ee tO) Os 2a | eae RA Ee 0 (?) 2/0 (2?) 0 0 Rose: (ONCE UC ee ee eso eee ZOD AT NSS eee Ja fee Ok eo gee Pe EP [A ene | | epee d4 1 OT eae ee eee eee SEC ba ete TG 4 2 2 |0(?) 2 (?) 4 Apple: (OG LSS ee eee Oust cae’ Henk 0 ) 0 |0(?) 0 0 Ne wesa=- Pas Roe ance RPO ope oa ee Ramee cess Ln Oe ee CM eee Se) ae ae See Sane 0 ae HAInY TOOL 2205-2. 2- PR a et ecg a A) (ae yeh eigen 0 0\0 0 0 SGU Nt SS 5 Se re Ueroe Seer ee 2 0 0/2 0 (?) Grapenera sea e so occsc cece (ee te oe ae a 3 0 0/)2 2 (?) 2 Olmehestmutss =... 3. ---2<5 DERE te ae Parone [oS eee 0 (2) 0/0 0 0 (?) PATER IBIS eee ee nisinid = (ie ae Samant nae 2 2 eee e0 0 T3101 fom et Sa Do oat 82 Sees kee? 0 0 | 2 (ol1) | 2 (old) | 0 (old) (CURR A (ee ee hee Seen Pee es Se ea |e ee cee 0 0\90(?) |f4 Chine Rees saeco la Seas oe Os pee te 0 | 20(?) 0 /0(?) 0 0 a Explanation of figures indicating growth: 0=No growth; 2=slight; 3=fairly good; 4=good; 5 =heavy. + Possibly no use of glycocoll by any of the strains. ¢ No increase in an additional 69 days. @ Turbid; cloudy on shaking. ¢ Forty-four days. J Forty-four days, another tube more copiously inoculated. g No growth later. h Plug wet. TaBLE XI.—Showing behavior of crown-gall organisms in river water containing 2 per cent Witte’s peptone and 1 per cent Schering’s c. p. glycerine. [Transfers from peptone bouillon culture 3 days old; records made at end of 27 days at 23° C.] Group. Organism. Character of growth. Heavy white rim and dense pellicle; scant clouding of fluid; mod- erate precipitate. On shaking, a dense mass of coarse fragments fills the fluid; 10 to 20 times as much growth as in group 2. Moderate white rim and thin pellicle; slight clouding; some pre- cipitate. Scant white rim, thin pellicle or absent; fluid moderately cloudy; some precipitate; about same amount of growth as in group 2, but distributed differently. 1| Old daisy*, peach*, hopf, cotton*, new rose*. 2 | Newest daisy*, apple hairy- root*, alfalfa7. 3 | Arbutus*, grape*, old apple, quince, beet (chestnut did not grow). Those marked with a star (*) gave distinct indol reaction without Tubes were now tested for indol. (See Table IX, p. 147.) The heating; those with a dagger (+), on heating. The others were negative. indol reactions were not as deep red as in case of Bacillus coli. 213 154 CROWN-GALL OF PLANTS. EXPERIMENTS WITH LITMUS-MILK CULTURES. Avuaust 2-3, 1910. Experiments to ascertain the behavior of the various strains of crown-gall organisms in milk gave the results shown in Table XIT: TaBLe XII.—Showing reactions of crown-gall organisms in sterile lavender-blue litmus milk at 80° C. ° Time. Strain. 3 days. 7 days. ' Newest daisy .-...-. | Bluer than check; no whey. .| Much bluer; no whey; strong peliicte. Old daisy... a ae QO Sense ..--| Litmus now dulled to a uniform plum beous; no whey. Salsityea 7. c.. ah OS 23 Much bluer; no whey. Wats poplar...135 | Soc. (< oe Sere .-| Uniformly much bluer; no whey; strong pellicle. Old chestnut. . alli Gielel eye sa Yea [ey ee SA rae Uniformly bluer than check; no whey. Turnip No. 2... Bluer than check; no whey ..| Much bluer; no whey. ATbWtHS-.~-»-- ...| Pinkish at top; paler blue be- | Rose purple at top; mauve below; not coagulated; low; no whey. no whey. COmen) cheeses cece Bluer than check; no whey .. tLe color verging on plumbeous; no whey; pellicle. 13 1G) oye Beers 2a x] AEN CES ee Ay an Ae tS Uniform dull blue, tending toward plumbeous; no whey; strong pellicle. Apple hairy-root...| Unchanged................-- Unchanged or nearly so. Newest rose. ....... Paler blue than check; no | Uniform blue, verging to plumbeous; no whey; whey. heavy pellicle. Quinees sue eee soe. 1 cm. purplish whey; dulled | Litmus color gone; whey translucent; curd digested purple below; curd dissolv- (nearly). The only trace of color is narrow pink- ing. ish rim. Old TOse5.. = eee es Bluer than check; no whey...| Uniform color, verging on plumbeous; no whey; strong pellicle. VANE EEE: GE ple eo Pe Bluer than check; trace of | Uniform deep blue; no whey; heavy pellicle. whey on top. Beeb Eas: - shed c fee Bluer than check; no whey...| Much bluer; no whey. Penchnn oo 2 fee. See GOD REE oh eee teae Uniform plumbeous; no whey; strong pellicle. Old apple.......... Purple red throughout and | Whey nearly colorless; pale pinkish firm curd at whey separated (this also bottom. on second day). Willowiomnen nce 5- = Bluer than check; no whey...| Much bluer; no whey. Grape® 22-5 2h a.2<2|2 <8 Gh es Sees ee en a Do. Murnip eos Les. sens (0 (yes ero 8 Se ee ae Uniform dull blue; no whey. Newpert poplar jase GOn eae uno Sens Much bluer; no whey. Onl: New chestnut.....- Unchanged; i.e., like check. .| Slightly bluer than check; no whey. Parsnip iso Aeee 2. Bluer than check; no whey...| Much bluer; no whey. Newpore poplar Blightly bluer than check; no | Nearly color of check; red rim. 0. 2. whey. Aueust 13, 1910. The litmus-milk cultures now fall into three distinct groups, as follows (temperature 28° to 30° C.): (a) Litmus a uniform gray; milk fluid, no separation of whey, moderate rim, heavy white pellicle, moderate white precipitate: Flats poplar, peach, old rose, cotton, hop, old daisy, turnip No. 1. (b) Litmus distinetly reddened, most at top: Old apple, quince, arbutus, Newport poplar No. 2. In the first two the casein has been thrown down, the bulk of the fluid being whey which, together with the clot, is now nearly color- less, i. e., only pinkish, with more evidence of solution of the curd in quince than in old apple. In the other two the milk is still fluid, i. e., no separation into curd and whey, and not yet much reduction. 213 CHARACTERS OF GALL ORGANISMS FROM OTHER SOURCES. 155 (c) Milk decidedly bluer than check, no reduction; in some a slight amount of whey on top of the fluid milk, in others no separation: Alfalfa, old chestnut, newest daisy, beet, parsnip, newest rose, new chestnut, grape, willow, turnip No. 2, salsify, Newport poplar No. 1. This group might be split again as follows: — (a’) Narrow pinkish rims and moderate pellicle over a uniformly deep blue fluid, and a white precipitate: Old chestnut, new chestnut, parsnip. (b’) The same, but with a pinkish-yellow precipitate and no pellicle: Beet. (c’) Heavy whitish pellicle, moderate white precipitate, uniformly dulled blue fluid: New rose. (d’) Very wide white rim (1 cm.), heavy peilicle, and scanty white precipitate: Aifalfa. (e’) Uniform deep blue with blue rims: Newest daisy, grape, sal- sify, willow, Newport poplar No. 1, turnip No. 2. Aueust 19, 1910. Group a.—No change except in the color of the milk, which is now a muddy tan color, with the exception of Flats poplar, which is still gray. Group 6.—No change. Group c.—(a’) Parsnip—no change; old and new chestnut— barely a trace of pink in the rims; no other change. (b’) Beet—no change. (c’) New rose—no change. (d’) Alfalfa—no change. (e’) No change. AueusT 26, 1910. Group a.—All (including Flats poplar—see August 19, above) are a dirty brown (approximately broccoli brown, Ridgway). Milk fluid, no separation of whey. Group b.—Quince: clot is being dissolved. Only slightest trace of color except in the rim, which is pink. Old apple—no change. Newport poplar No. 2—casein is being thrown down; very little reduction. Arbutus—miulk coagulated, no separation of whey; no reduction. Group c.—(a’) Parsnip: no change (milk fluid, bluer than check; no separation of whey). New chestnut—no pink in the rim, otherwise unchanged. Milk fluid, bluer than check; no separation of whey. Old chestnut—milk fluid, no separation of whey; but reduction is taking place. Milk approximately Ridgway’s lavender gray. (b’) Beet—milk fluid, deep blue; no separation of whey. Pinkish yellow rim and precipitate. (c’) New rose—like old chestnut in color, but slightly bluer; otherwise as on August 13. 213 156 CROWN-GALL OF PLANTS. (d’) Alfalfa—no change except that milk is paler blue than on August 13 and 19. (e’) Salsify and grape have white pellicles and are much paler blue than the others in this group (reduction probably taking place slowly) ; milk fluid, no separation of whey. No change in the others (all deep blue) except that newest daisy has a pellicle (whitish). Milk fluid in all, and no separation of whey. Apple hairy-root is exactly like check. Probably no growth. The Flats poplar was tested in milk with results very different from those Brizi obtained with his Bacillus populi: Three tubes of sterile white milk were inoculated copiously on July 28, 1910, and kept at 28° to 35° C. In 28 hours there was no visible change. In 4 days no separation of whey or change in appearance of the milk. In 9 days a copious white bacterial pellicle, but still no separation of the whey or curdling of the milk.* SILICATE JELLY. The behavior of all the crown-gall organisms on silicate jelly was much alike (one test only). There was a feeble to moderate white growth divisible into two groups about as follows: (1) Smooth surface, growth rather scanty: Old daisy, newest daisy, grape (?¢ growth), new chestnut, arbutus, old apple, new apple, apple hairy-root, beet, quince. (2) Surface papillate-rugose but smooth on the margins, growth more abundant: Cotton, alfalfa, old rose, Turnip No. 1, hop, new rose, Flats poplar. INOCULABLE AND CROSS-INOCULABLE. Whether the different behavior of galls on various individuals of different hosts, sometimes forming soft, rapidly developing spongy excrescences and sometimes hard, slow-growing, slightly elevated tumors, or abnormal clusters of roots, as for example in the apple, is due principally to individual differences in rate of growth or juiciness of the particular tissues involved, to the particular tissue first infected, or to some other cause, must be left an unsettled question. The writers are inclined to think that there are several races of the gall-forming organisms varying more or less in amount of virulence and in adaptability to various hosts. Starting from soft gall of the peach, hard gall was produced on apple; and in the a On potato cylinders inoculated at the same time and from the same culture, the color of the slime at the end of 28 hours was white like that of the potato substratum. In 4 days the slime was thin and dirty white. In 9 days the bacterial layer, which had not increased much, was a dirty white, and the fluid slightly brownish. The slime was not yellow and there was no marked action on the starch. At the end of a month when tested with alcohol iodine the potato cylinder gave a strong starch reaction, but thecolor , was purple instead of deep blue (check). 213 EXTENT OF CROSS-INOCULABILITY. 157 same way from soft gall of daisy the hardest of hard gall on daisy. But inoculating with an organism plated from hard gall of the apple into actively growing soft daisy stem a series of galls were produced more resembling the original hard gall of the apple from which the colonies came than any typical soft gall of the daisy (Pl. III). On the other hand, as already detailed, starting with an organism from apple hairy-root and inoculating into young apple tree roots one developed galls while the others developed hairy-root. From one of the galls, however, on the tree which developed only galls, an organism was plated out which looked typical for what was inserted, and this when inoculated into healthy sugar beet produced both galls and hairy roots, indicating that crown-gall and hairy-root are only two forms of the same disease. Clustered roots also formed on one gall on Brassica. This hypothesis is further borne out both by the fact that the hairy-root clusters often originate in slow-growing hard galls and by the observation that rootlets frequently appear on peach galls in early stages of their development, but do not persist. The same phenomenon, transitory for the most part, occurs frequently or occasionally in some other galls, i. e., daisy, grape, clover, alfalfa. Attempts at cross-inoculation have shown numerous differences (Tables II and III) the explanation of many of which must be sought in further experiments. Strains taken from some hosts, e. g., daisy, peach, hop, were inoculated into other plants with great ease. The strain obtained from the rose was inoculated into other plants with difficulty, but inasmuch as tumors were not readily produced on the rose itself by such inoculations it may be only that we were unfortu- nate in the selection of our rose bushes or of the colonies for our subcultures, getting slightly virulent strains. It is certain from our experiments on the daisy that a virulent strain may gradually lose its power to infect when kept for several years under laboratory con- ditions, and it is very probable that in nature some strains are feebly infectious and others actively infectious. But we know in case of certain bacterial organisms cultivated in the laboratory that lessened virulence can be restored by certain procedures and we are not warranted in assuming that such restora- tion may not also take place in the fields. DISCUSSION OF QUESTION OF SPECIES, VARIETIES, AND RACES OF THE CROWN-GALL ORGANISM. Have we to do with one species or several? The answer is not at hand. Indeed, to those who have read thus far, it must be evident that much further time will be required to decide positively whether it is best to regard all crown-galls as due to variations of one polymor- phous species, or whether they should be separated into two or more 213 158 CROWN-GALL OF PLANTS. species. Certainly there are not as many species as there are host plants, and the ease with which in many cases cross-inoculations take place points rather to one collective species. The monotonous morphology also points in the same direction, but the evidence is not all in. In this connection the reader is advised to make com parisons with the literature on root tubercles of Leguminosae. The differences we have observed may be noted by consulting the tables and these seem to be real differences, e. g., slight differences in color or amount or texture of growth, ability or inability to grow in Cohn’s solution, reactions in litmus milk, toleration of acids, ete. The difficulty is we do not know exactly what these things mean in the microbian economy, nor what weight to give them as differential characters. Al! told, the points of resemblance or agreement so far as we have studied the subject are much more numerous and salient than the differences, and for the present at least we prefer to leave the group undivided, merely indicating the various cultures for pur- poses of convenience by the name of the plant from which derived, as daisy, peach, poplar, ete. Certain very practical questions arise here, viz, would it be advis- able in nursery and orchard practice to follow one galled crop by another crop subject to galls, e. g., peaches by apples or pears, rasp- berries by grapes or quinces, or roses by almonds? Admitting frankly that we do not yet know the extent of artificial cross-inocula- bility, much less that of natural cross-inoculability, and that many more observations and experiments need to be made before we can be quite certain in particular cases to what extent the galls are naturally cross-inoculable, the grower who reads carefully the evi- dence detailed in this bulletin will probably hesitate to take the risk. LOCAL REACTION OF THE INOCULATED PLANT. YOUNG VERSUS OLD TISSUES. In general old and hard, slow-growing tissues are not favorable to the development of this disease, whatever the host species concerned. Inoculations into such tissues frequently failed. Inoculations into dormant tissues usually failed, even though such tissues began to grow in the course of a few weeks. Mature tissues are not suited for inoculation experiments. The most uniform success was had when the inoculations were made into young and rapidly growing parts. In such cases it is often possible to obtain 100 per cent of infections (see Table II). Appar- ently it is sufficient to introduce the bacteria into any actively divid- ing tissues of root or shoot—cambium, xylem, phloem, bark, pith, or mesophyll. Whether the structure of the tumor tissue in such cases 213 CHARACTER OF THE TUMOR. 159 is dissimilar and whether the metastases partake of the nature of the original tumor are subjects requiring much further study. In sensitive tissues the tumor reaction begins at once, and can be seen as a slight elevation about the needle pricks as early as the fourth or fifth day, and in the form of perfectly developed, small, fleshy growths a few days later (daisy, peach, etc.). STRUCTURE AND GROWTH OF THE TUMOR. The gross appearance of these tumors when they occur on crucifer- ous plants somewhat suggests the ‘‘finger and toe’’ attributed to Plasmodiophora brassicae. It is not a remote inference that all phe- nomena of this character on the roots of crucifers should be attributed to bacteria, particularly as no clear-cut inoculations with Plasmo- diophora have ever been obtained. By this is meant inoculations which would clearly exclude the possible presence of pathogenic schizomycetes. But the chances are against such being the fact. We have not made enough experiments to be able to say positively that crown-gall bacteria never occur associated with the Plasmodio- phora, but in opposition to this view, and favorable to the autonomy of the finger and toe disease, is the structure of its tumor, which shows very little hyperplasia and a great amount of hypertrophy, especially of the cells occupied by the spores of the Plasmodiophora. Moreover, the phloem is a favorite point of attack in finger and toe. Probably the correct view is that these are two distinct gall diseases of crucifers. Writers on malignant animal tumors are correct in asserting that the Plasmodiophora tumor is anatomically quite unlike the tumors with which they have to deal. The anatomy of the crown-gall having proved a much easier sub- ject than the etiology, there is a considerable body of literature respecting the structure of the galis, the details of which need not here occupy much space, since we contemplate a special paper on the subject. Those who wish to know more may refer to the following authors for structure of the tumors of the plants specified: Almond and peach (Toumey); rose (Scalia); sugar beet (Briem); raspberry (Wulff); poplar (Brizi). The contentions of these writers agree in the main, and the principal facts set forth by them are not contra- dicted by anything we have observed. Some additional observations and inferences may here find place. In crown-gall we may assume either (1) a direct stimulus to growth or (2) an indirect one through the removal of some norma! inhibition. Probably the first is the true explanation. The tumors appear to be | able to arise from any meristematic tissue, i. e., from any cells of the organism which are able to divide. They are not subject to any physiological limitation. In a way, of course, the growth that 213 160 CROWN-GALL OF PLANTS. takes place in crown-galls is like that seen in the regeneration tissue of wounds, but that growth is governed by a physiological need and ceases with the repair of the wound, whereas the gall tissue prolif- erates indefinitely, passes beyond the control of the plant, and becomes a wasting disease. So far as the tissues themselves are concerned, the chief difference appears to lie in the different distri- bution of the various elements, the overplus of parenchyma, the weakening of the conductive tissues, the persistent prevalence of meristematic (embryonic) cells, and of immature forms generally, e. g., defective vascular bundles. Crown-galls vary greatly not only in virulence, but in their structure from species to species and also from individual to individual within the species, depending, appa- rently, on where the tumor takes its origin, i. e., whether it begins in pith or bark or wood or on the lamina of a leaf. Sometimes the tumors are very woody and hard, their structure consisting chiefly of twisted and contorted lignified vascular bundles and woody fibers mingled with more or less parenchyma.. At other times, and very often, the structure consists mostly of rapidly pro- liferating nests of parenchymatous tissue of a round-celled or spindle- celled type (Pl. XXXII), intermixed with which are vascular bundles (conductive tissues), more or less lignified, but twisted out of their normal shape, with walls abnormally thin, the total mass of the conductive tissue being less by far than that encountered in normal tissue, i. e., there is an enormous excess of the rapidly proliferating parenchyma and a corresponding reduction of conductive tissues. The cells of the hyperplasia are often much smaller than the cells of the tissue in which it originates, e. g., inoculated tumors in certical parenchyma of tobacco stem (Pl. X XIX). There is never any enor- mous stretching of individual cells such as we find a common phe- nomenon in the galls containing Plasmodiophora and in those formed by the nitrogen tubercle organism of Leguminosae. On the contrary, the stimulus to division is so active that the cells do not have time to attain their normal size. The mechanism of division is a subject for further research. In young, rapidly growing daisy tumors fixed for that purpose we did not find many karyokinetic figures, but in a rose gall numerous double nuclei were observed lying close together in undivided cells. Toumey observed this in almond. In our pure-culture inoculations where several needle punctures have been made close together sometimes only one gave rise to a tumor; sometimes all or nearly all of them developed inde- pendent tumors which fused into one mass as growth continued. A study of sections of the earliest stage of tumor development might lead to interesting results respecting the cells first infected. This we propose to undertake. The tremendous proliferation prob- 213 CHARACTER OF THE TUMOR. 161 ably begins in a single cell or in a few cells and perhaps from a special tissue, but whether the impulse to division must always come from within the infected cell, this impulse being transmitted only to its daughter cells, and so on, or may also be external, influencing neigh- boring groups of cells, remains to be determined. When this double phenomenon appears, to wit, overproduction of parenchyma and corresponding reduction of vessels, and it occurs very often not only in the daisy, but also in the sugar beet, peach, hop, and many other plants, the tumors do not appear to be able to obtain as much water and nourishment as is required to carry them beyond a certain point in growth, and portions of the morbid tissues slough off, necrosis following growth in the course of a few months. It is seldom that the primary necrosis involves the entire tumor; some portion of it, generally the margin, remains alive and proliferates more or less extensively the same season or the following season, forming additional tumor tissue, which subsequently extends the open wound by additional necrosis. Where the woody fibers are more abundant this phenomenon does not occur, or takes place at a more remote date. In other cases the tumor regresses and no new one appears. SUGGESTED RELATIONSHIP TO ANIMAL TUMORS. The writer can not help feeling that the phenomena displayed in a rapidly proliferating tumor of the type figured and described in this bulletin shows a likeness to certain tumors occurring in the animal body, namely, to sarcomata. These plant tumors often grow very rapidly, and when the plant is a small one either destroy it within a few months or greatly injure it. They seem to be much more nearly related to sarcomas than they do to inflammatory processes, to which some of the animal pathologists with whom we have talked have been inclined to liken them. Exclusive of the presence of leucocytes, which do not occur in plants, and of swelling, which even in animals is not the invariable accompaniment of an abscess (e. g., abscess in bones), we have in plants phenomena quite like abscesses in animals, but these phenom- ena are in no way like crown-galls. They consist of the formation in the stems or other parts of plants of more or less extensive cavities or chains of cavities filled with fluid, broken down portions of the tissues, and a greater or less number of the bacteria which have caused the disorganization, together usually with saprophytes of various kinds. Such phenomena occur in bacterial diseases of potato, maize, sugar cane, cabbage, pear, etc., but they are purely disorganizations (areas of softening), not abnormal organization processes. In the abscesses no new organs are formed. The most the plant is able to 78026°—Bull, 213—11——1] 162 CROWN-GALL OF PLANTS. accomplish under conditions favorable to it is the formation by cell division of a protective cork layer about the diseased area somewhat as the tissues of the animal body for the same purpose inclose tuber- culous nodules or syphilitic gummata with a fibrous mass of connective tissue. According to the current medical classification of tumors, crown-galls belong with the infectious granulomata apart from the true tumors, but it is not likely that such classifications represent anything more than a temporary phase of progress in pathology, because they rest largely upon absence of knowledge. One by one as the causes of tuberculosis, lepra, syphilis, actinomycosis, ete., have been discovered these diseases have been removed by medical writers from the domain of tumors and classed as specific inflamma- tions, but logically if parasites should be discovered all the remaining malignant growths would have to be removed, leaving nothing but the empty pigeon hole for tumors. Unlike teratomas, these tumors do not have a restricted growth comparable to a defective normal growth. Teratomatous growths are frequent in plants, but quite unlike the cell development here in question. Neither are crown-galls to be regarded as degeneration processes. We have in plants certain disease phenomena, namely, cedemas, which seem to be more like degeneration processes in animals than are the growths here described. In cedema, which is believed to be nonparasitic, we have swelling from excess of water supply and more or less enlargement of parenchyma cells, but it does not usually pass beyond simple hypertrophy and does not involve such hetero- geneous hyperplasiac tissue changes as are conspicuous in the crown- galls. Some of our gum diseases of unknown origin show somewhat similar degenerations, formation of internal cavities, with enlarged cells in the walls. In crown-galls no abscess cavities have been observed. Cancers occur in a variety of animals, and no good reason has been advanced why they should not occur in plants. These tumors are morbid new tissue developments tending to weaken and destroy the plant, and their structure does not suggest galls due to insects. Insect galls are usually of quite specific structure and definitely restricted growth, whereas the crown-galls are of indefinite structure and indeterminate growth. As a working hypothesis, we may regard insect galls as due to a localized and fleeting stimulus of a chemical nature not unlike the more generalized and prolonged stimulus which leads to cell division in crown-galls. The determination of the imme- diate cause of cell division in the one would probably throw much light on the other. Certain resemblances to malignant animal tumors may be pointed out in more detail. 213 CHARACTER OF THE TUMOR. 163 In the crown-gall there is not only enormous proliferation of the parenchymatic tissues (often in nestlike masses), but there occur in the tumor also all the other tissues normal to the organs attacked, although usually the woody tissues—the conductive ones—are greatly distorted and reduced very much in volume. They are there, how- ever, permeating the tumor in various directions. Some portions of them are seen on sections as small ligneous islands and others as more or less lignified short tubes; but these fragmentary appearances are due simply to the direction of the knife cut, and careful dissection of the part shows that the ligneous conductive tissues arise from the base of the tumor and twist and branch in various directions through it, becoming reduced to widely separated single vessels or pairs or small groups of vessels in the remoter portions. This fact should, perhaps, count for more, in our judgment, as to the analogies of these tumors than the appearance of the rapidly proliferating parenchyma cells, which, however, strongly suggest malignant tumor tissue of animals, as may be seen by referring to Plates XXVI to XXX. (See also Plates VIII and XXI.) Undoubtedly many of the supporting elements in crown-gall, perhaps all, grow out of the substratum along with the growth of the tumor (PI. X XVI, lower figure, Y). Insome instances in large tumors it would seem as though some of the vessels were produced in place from the tumor itself, but of this we are not certain. Another suggestive likeness is the fact that in this disease, and likewise in the olive-tubercle, there are well marked metastases, that is, secondary tumors arising from within, at some distance from the primary tumor, as the result of migrations, but as yet in the crown- gall we do not know the mechanism of this migration, i. e., whether the bacteria move independently through the tissues, setting up irritations in more or less remote places, or whether the migration takes place only within special host cells. In many plants cells push through small pits in vessel walls, forming in the interior of the vessels numerous rounded growths known as thyloses. These often contain bacteria. If they should become dislodged, they might then fall or be carried upward in the direction of the water current to become, if still able to divide, the center of a new growth elsewhere, quite after the manner of malignant animal tumors, assuming metastases of the latter to originate always in this way. Observa- tions of Hunger on the brown rot of tomato and of the senior writer on the same and on mulberry blight show that thyloses are developed in vessels as the result of bacterial infection. Usually, in thyloses the irritation is temporary and tumors are not developed, although in case of the roots of old cucurbits it is common to find woody vessels compactly filled with a pseudo tissue composed of thyloses. 213 164 CROWN-GALL OF PLANTS. Whether this suggested mechanism of distribution actually occurs in the crown-gall must be left for further study. Owing to the absence of visible channels of infection and to the difficulty of staining the schizomycete in situ, we do not know where nor to what extent it occurs in a dormant condition outside of the tumor proper; but in a very interesting and destructive fungous gall of West Indian lime trees, studied in the Laboratory of Plant Pathology for several years, Miss Florence Hedges has demonstrated that the fungus may grow through the stems to a distance of several feet from the primary tumor before an internal secondary tumor develops. The distance in one case was so great that the writer of this paragraph supposed it to be a second external infection until proof to the contrary was obtained by tracing the internal mycelium through the wood from ' the primary to the secondary tumor. Here the bulk of the abnormal growth consists of wood. A bulletin on this subject isin prepara- tion. It is probable that the parasite in its migrations from one part of the plant to another does not make free use either of the vessels or of the intercellular spaces, at least we have not been able to find it in them. Rather we think it is imprisoned within the specially stimu- lated and rapidly dividing cells and is by the growth of these cells carried along. The location of the visible metastasis would then depend on where the most favorable conditions for rapid growth developed. There would then be a slight chain of morbid cells all the way from the primary tumor to the secondary one. Further studies are necessary. Plate XXX shows a photomicrograph made through a young “metastatic tumor in the petiole of a daisy leaf. The whole interior is a mass of rapidly proliferating morbid tissue (parenchyma cells and distorted bundles), but it has not yet ruptured to the surface, the outermost tissues being the normal tissues of the leaf stalk. Later such a tumor would tear apart these tissues and appear on the surface. The primary tumor in this case was some months older and situated lower down on the stem. There are some indications in this section that tumor cells are growing between and wedging apart larger normal parenchyma cells (infiltration?), and this phe- nomenon may be seen conspicuously in the section shown in Plate X XVII. A third likeness which seems to us of some importance is the fact that a certain degree of immunity can be induced in the plants by repeated inoculations. When several inoculations have led to the formation of successive galls, it is then usually impossible to induce galls in the affected daisies by inoculating again with pure cultures of the same strain which produced the initial tumors, One set of 213 CHARACTER OF THE TUMOR. 165 successful inoculations does not suffice to produce this quasi immunity, but several are required. Even then it is possible by inoculating with a more virulent strain to induce tumors on these plants, although as far as our observation goes, the tumors are slower to appear and gen- erally smaller and less vigorous in their growth than on check plants (p. 177). Spontaneous recovery from the disease is quite frequent. A fourth likeness is the tendency of the disease to appear in callous or scar tissue, e. g., on pruned roots or at the junction of stock and graft. This appears to be rather more than mere presence of wounds in these places. The wounds must probably exist, but the softer, modified character of the new tissue appears to invite both wounds and infections, just as it also invites secondary fungous and bacterial infections. A fifth resemblance consists in the marked tendency of the galls to return after excision. Sixth, the fact frequently observed by us that on agar poured plates made from tumors, especially those of some age, certain colonies which look like those of the right organism and which behave properly when transferred to peptonized beef bouillon either do not produce the overgrowth when inoculated into susceptible plants, or yield only very slow-growing, feeble, soon stationary hyperplasias, requires explanation and may be mentioned here. At first these results were interpreted by us as meaning accidental presence in the tumors of organisms resembling Bacterium tumefaciens on agar, etc., but unlike it in other respects. More recently we have come to the conclusion, or rather formed the working hypothesis, that these per- plexing colonies, or at least some of them, must be nonvirulent strains of the gall-producing organisms, not other species. We do not know what constitutes virulence, but we do know that on culture media many organisms gradually lose this property, Bacterium tume- faciens being one of them. The question then arises: Why should not virulence often disappear from organisms buried inside the tissue of tumors? And is not the fact that the tumor has ceased to be active and the host has gained the ascendency evidence of this? It is certainly conceivable that either by the juices of the host or through their own by-products the bacteria might be so acted upon as to lose power to infect other plants when cultivated out, and this without losing their common cultural characters. The same phe- nomenon is believed to occur in cultures of the organism causing root tubercles of Leguminosae. It is believed by us that we have here the beginning of a solution of the cancer problem in men and animals, or at least a most instruc- tive border-line field. The chief objection raised by animal pathol- ogists with whom we have talked to considering these tumors in the 213 166 CROWN-GALL OF PLANTS. light of cancers is the fact that we know them to be produced by a specific organism, hence they are granulomata. If we did not know them to be so induced, then they would be willing enough to consider them as tumors. This is shown by the fact recently called to our attention, i. e., after these pages were prepared for the printer, that in the International Conference on Cancer at Paris in October, 1910, Professor Jensen (of mouse-tumor fame), not knowing of our re- searches, presented without hostile criticism a paper (Von echten Geschwiilsten bei Pflanzen) on the crown-gall of the beet, in which he maintained it to be not only a true neoplasm, but a genuine tumor for which he predicted a réle as important in cancer research as the mouse tumor itself has played. His exact words are: 7 Obwohl meine Untersuchungen nur noch einen vorliufigen Charakter haben, glaube ich doch, aussprechen zu diirfen, dass wir beim ‘‘Wurzelkropf’’ nicht nur mit einem echten Neoplasmus sondern gar mit einem Tumor zu schaffen haben, der in gewissen Beziehungen Aehnlichkeit mit den malignen Geschwiilsten der Tiere darbietet; ja, ich bin geneigt zu glauben, dass er in der Geschwulstforschung eine Ghnliche Rolle spielen kinnen wird, wie jetzt die Méusecarcinome.—Page 248. And again, on page 254: Wir haben also in dem sog. Wurzelkropf eine Geschwulstbildung vor uns, die auf einer andauernden, abnormen Proliferationsfihigkeit gewisser Zellen zu beruhen scheint, und die nicht nur dadurch, sondern auch durch ihre Beeinflussung des Wachstums der Riibe, thre Féhigkeit zu rezidivieren und sich transplantieren zu lassen, so wie durch die abnormen chemischen Verhiiltnisse der Zellen so sehr an die malignen Tumoren der Tiere erinnert, dass ein niiheres Studium der biologischen Verhdltnisse der Geschwulst unzweifelhaft wohl angebracht wire. The animal pathologists have not come to any agreement as to what is the cause of sarcoma, carcinoma, and similar tumors, some holding them to be due to organisms, either known or suspected, while others, now the majority, maintain that inasmuch as inocula- tions of certain ground cancerous tissues have not led to any infec- tions and inoculations of uninjured tumor tissues of the same sort have led to numerous and repeated infections, therefore the disease can be transmitted only by the living proliferating cancer cells, e. g., experimentally by grafting. As clear a statement of this view as any, perhaps, is that given by Dirck: The essential difference between infectious growths and genuine tumors is that when the former are reproduced by metastasis the parasite itself is conveyed in the blood and incites at the metastatic site new formation of tissue similar to that of the parent growth, whereas in the case of genuine tumors metastasis takes place by the transplantation of a part of the parent tumor, which then begins to proliferate inde- pendently at the new site. But we are totally in the dark as to what originates cancer cells or causes them to proliferate. Tt has been known for a considerable period, i. e., since 1900, that crown-galls could be inoculated into healthy plants by means of 213 CHARACTER-OF THE TUMOR. 167 pieces of tissue and that tissues so inserted would grow into a new tumor, and in that period we were in precisely the same condition as the animal pathologists of to-day, who reproduce mouse tumors and similar malignant growths by introducing pieces of the diseased tissue under the skin of healthy animals, but can not explain the reason why. We did not then know that such plant tumors were due to a specific organism, and a good many of us were very skeptical as to the existence of a parasite, because after repeated careful searches by a good many people no such organism had been demon- strated in situ by means of the microscope, and the things which had been plated out of such plant tumors and tested on healthy plants had produced in them nothing comparable to the growth from which they had been taken. Enough such experiments have been made and by a sufficient number of persons to show that unless one knows just how to set to work it is not at all easy to obtain the pathogenic organism from crown-galls. As stated in the beginning of this bulletin, we boggled away at the problem a couple of years before we were certain by isolations and inoculations that we had in a particular micro-organism the specific cause of the disease. Our troubles were of various sorts. First of all the tumor tissue when it has reached any considerable age is rapidly invaded by secondary organisms, i. e., saprophytes, and on the plates these are the ones that we commonly obtained. Isolation is also complicated by the fact that the organism which is the cause of the disease is a rather sensitive one, i. e., fre- quently is killed out quickly in the struggle with saprophytes. The problem was further complicated by the fact that on standard +15 nutrient agar, which was our common substance for poured-plate isolations, the initial growth of the bacteria taken directly from the interior of the tumor and distributed in the agar plates is extremely slow, so that often colonies visible to the naked eye are not seen before the fifth or sixth day, and sometimes not until the tenth or twelfth day or later. In other words, the saprophytes would come up quickly and be studied and the overgrown plates discarded before the right organism would appear at all. The writers also believe that the organism in the tumors either multiplies very slowly or if growing at an ordinary rate is killed off rather rapidly by the chemical reactions of the plant itself, or by the by-products of its own growth. We have been led to this hypothesis by several facts. First, it is not easy to obtain stained preparations of the tumors in which the bacteria can be demonstrated. After six years we have to show not a single good preparation. We get numerous granules of the size of bacteria, and some of them of the general outline, but so far with few exceptions none which take a sharp stain leaving well-defined walls such as one looks for in order to be reasonably certain that he has bacteria in his preparation and not 213 168 CROWN-GALL OF PLANTS. something else, e. g., cell detritus. The fact that the organism as it occurs in the gall comes up slowly on agar poured plates, but grows as promptly as other bacteria in the same medium when transferred from cultures, may be coupled with the fact that irregularly shaped involution forms are common in this species when it is exposed to certain unfavorable conditions, e. g., cold or sodium chloride. If such involution forms were the common form also in the plant, it might explain many of our failures. Such club-shaped and branched forms occur abundantly in some of the nitrogen root nodules of Leguminosae. If this were true, namely, that there is a pretty nearly even balance between the growth of the bacteria in the tumor tissue and the destruc- tion of the same, then we might have the tumor rapidly proliferating as the result of the stimulus of enzymes, toxins, acids, alkalies, or other substances, dissolved out of the dead bacteria, and not in the tumor at any given time very many bacteria demonstrable by means of stains, because inactive and partially disorganized bacteria are proverbially difficult to stain.¢ Might not some phenomena of the kind mentioned be present in malignant animal tumors and thus complicate the determination of their etiology? We know in case of the crown-galls, even when we can not stain the bacteria in the tissues, that they are there, because by selecting small tumors no part of which has yet passed into a necrotic condition we can obtain therefrom cultures of the gall-producing organism, and have done it over and over again. All that it is necessary to do is to scrape thoroughly and wash the unfissured surface of the gall, then soak it in some germicide long enough to sterilize the surface (an hour or less in 1:1,000 mercuric chloride water usually suffices), dry it, and dig into the depths of the tumor (or in case of hard tumors into superficial rapid-growing portions) with sterile instruments, remove and crush some of this interior portion in sterile bouillon, and make poured plates in +15 nutrient agar. We are further led to the belief that living bacteria are not numerous in the galls by the fact that even when the melted cooled agar for plates is inoculated rather copiously, what one would ordinarily call very copiously (say, 1,000 or 10,000 or even 100,000 times too much) if he were dealing with other diseases, the colonies developing on the plates (which under the conditions mentioned are sometimes absolutely free from in- truders) are not very numerous. Third, even this procedure will frequently fail to. yield any colonies, unless one also takes the added precaution of allowing the living bacteria present in the partially a Since this was written we have obtained numerous involution forms in agar and bouillon by adding weak acetic acid. These facts, coupled with the knowledge derived from the flask analyses, viz, that acetic acid is formed from sugar by this organism, makes it very probable that both acetic acid and involu tion forms occur in the tumor. 213 CHARACTER OF THE TUMOR. 169 crushed tissue ample time to diffuse out into the bouillon by letting it stand for half an hour or an hour before the plates are made. This is additional proof that the number of viable and stainable bacteria in any given portion of the tumor tissue is rather small, so as to be hard to find, unless it be that the bacteria are abundant but intracellular to such an extent, i. e., so intimately mixed with the protoplasm, that they do not readily diffuse out of the partially crushed tissues. Certainly there is nothing in the crown-gall comparable to the phe- nomenon seen in the nitrogen tubercles of legumes where the hyper- trophied cells become gorged with bacteria, easily seen as such whether stained or unstained. With good technique the right organism can be obtained by means of poured plates from almost any rapidly proliferating part of the crown-gall tumor, but often not at all if one tries from older portions of the growth, i. e., those more remote from the active centers of growth. The isolations are also sometimes complicated by the fact that of two colonies on an agar poured plate looking just alike, one may be able to cause the disease and the other destitute of pathogenic properties. The difficulties we have encountered in determining the etiology of these tumors make it only reasonable to suppose that similar dif_i- culties would be encountered in isolating the parasites of animal tumors, admitting for the time being that they are due to organisms. This is also suggested by the past difficulties encountered in deter- mining the cause of tuberculosis, lepra, and syphilis: A few sugges- tions may be offered for the consideration of pathologists who believe malignant animal tumors to be of parasitic origin, but have not been able to demonstrate the suspected parasite. (1) All present cellular theories of cancer origin are incompetent to explain how such cells originate, i. e., become cancerous, or why they multiply; and in the light of the facts here presented we would suggest that renewed search be made for a parasitic organism or virus either independent of specific cells or confined to them and using them as a means of dissemination. It would seem that the initial cancer cell or cells in an organism must result from the action of a foreign organism or virus, whatever may be thought of the process of abnormal growth once established. (2) If we may assume the suspected parasite to be present in the - tissues in an active state in very small numbers only, owing to the nearly balanced struggle of the host against the invading organism, and the rapid destruction also of the causative organism in many parts of the tumor, owing to the invasion of saprophytes, then one might well have failed to produce the disease by injection of small quantities of ground-up cells without this bemg conclusive evidence 213 170 CROWN-GALL OF PLANTS. of the nonparasitic origin of the tumor, either no parasites being introduced or so few and these so reduced in vitality by long presence in the tumor or by exposure to the juices of the crushed cells, which we may suppose to be more or less germicidal, that they are overcome and destroyed by the normal activities of the body. It is possible also that there may be some special mechanism of infection. Here might also be pointed out that most of this evidence has been derived from mouse tumors, and that we are under no obligation to consider all malignant tumors as etiologically identical. (3) A parasite might be present and not isolated because unable to grow on the media commonly offered to it, as in the case of syphilis and yaws. The most striking evidence of this nature the senior writer has had brought to his attention was the failure of a strepto- coccus associated with endocarditis to grow on media obtained from one of the best human pathological laboratories in the country, but which grew readily in slightly different media. The growth of the organism, as was afterwards determined by him, was inhibited by the presence of too much sodium hydroxide in the bouillon. This particular organism he also observed to be very sensitive to sodium chloride, so that a slight excess of sodium chloride in the agar or bouillon would also inhibit growth. Had only one bouillon or agar been used the experiment would have failed. This organism was isolated in + 15 agar and bouillon, but would not grow in zero bouillon or agar (October, 1906). In the light of these facts there can be little doubt that many of the blood tests in arthritis and endocarditis which have been described as negative by various physicians and surgeons are to be regarded as failures due to the use of improper culture media, rather than as proof of absence of organisms in the blood or other fluid tested. Why not failures of this kind also in other fields of animal pathology? In recent years but few serious attempts appear to have been made to isolate a parasite from malignant animal tumors. The variety of difficulties encountered in obtaining cultures of the organisms causing tuberculosis, lepra, syphilis, rabies, etc., should also be considered; e. g., pathologists have been satisfied for a long time as to the cause of leprosy, being able to stain a certain acid-fast organism within the cells, but not until very recently has it been possible to grow it in pure culture and with subcultures therefrom reproduce the disease in mice (Duval: Jour. Exp. Med., 1910, Vol. XII, pp. 649 to 665). (4) Failure to demonstrate the supposed parasite in stained sec- tions might be due either to its scarcity, to its indifference to stains, to its lack of power to retain them during the washing, or to the fact that it may occur in the tumor in some very minute or unusual form, 213 CHARACTER OF THE TUMOR. Bel e. g., in involution forms. In this connection see a paper by S. B. Wolbach and Tadasu Saiki on the presence of bacteria in normal livers, demonstrable by cultural methods but not by stains (The Journal of Medical Research, Boston, September, 1909, p. 274). (5) The likeness of crown-gall to animal tumors might be thought at first sight to be lessened, owing to the fact that plants of many sorts can be made to take the disease by means of grafting or pure culture inoculation, whereas animal tumors are supposed to be very restricted in cross-inoculability. One reason for this difference may lie in the greater simplicity of plant structures, plants being much less highly specialized than vertebrate animals. It is possible also that the doctrine of non-cross-inoculability of animal tumors may be a sweeping generalization based on insufficient evidence. Recently Van Dun- germ states that he has successfully inoculated sarcoma of the rabbit into the hare; and Sticker claims to have produced dog tumors in the fox. (6) The most difficult thing to explain on any parasitic theory is the character of the metastasesin cancer. These are so characteristic, and so like the tissues of the original tumor that from an examination of sections of the secondary tumor it is often possible to determine where the unseen primary tumor is located, whether, e. g., in the stomach or the ovaries. This, however, does not seem to be an in- superable objection. Vide Mihlman, Ueber Bindegewebsbildung, Stromabildung und Geschwulstbildung—Die Blastocyten Theorie (Archiv. f. Entwickelungsmechanik, 28 Bd., pp. 210-259). It is not yet beyond dispute that a cell mother of one kind can never give rise to a cell of another kind when a changed stimulus is applied. Adami and several others maintain that particular animal cells forming a normal part of tissues, i. e., not in juxtaposition with the proliferating mass of morbid tissue, may become cancer cells. METASTASES. It had been noticed during the early part of our work with the gall organisms that when a daisy plant, never before affected, was inocu- lated and galls were produced, the disease did not confine itself to the inoculated part or its immediate neighborhood, but made its way to other parts of the plant. This was shown by the marked tendency of galls to form on leaves or parts of the stem other than that part on which galls developed as the result of our inoculations. Some of these galls may have been due to accidental surface infections, but it seemed that all of them could not be ascribed to local surface infections for several reasons, i. e., because the check plants in the same house remained remarkably free from infection, because the hothouse was quite free from small animals likely to cause 213 172 CROWN-GALL OF PLANTS. wounds, and because some of these galls were observed to arise from the deeper tissues and to push up the sound superficial tissues (Plate XXX) several days in advance of any actual rupture of the latter. — When the first cuttings were made from the first galled plants, notes were kept of the behavior of these cuttings, and, of 33 made, 18 developed galls within six weeks. Some of the galls were under- ground on the base of the cutting, some were at the surface of the earth, and some were on the upper part of the stem. Finally, experimental inoculations into the leaf-traces under the point of insertion of the leaf, caused, first, the appearance of galls on the stem where the needle entered, and subsequently at a dis- tance, internal galls. These internal galls appeared along the line of the punctured leaf-traces in the petiole and on the midrib of the leaf, several centimeters from the primary galls, and gradually ruptured to the surface. The plants selected were sound and there could be no question of the secondary galls having originated from within, and as a result of some stimulus due to the primary gall, both because they appeared exactly where it was reasoned out in advance that they should appear, and because they were watched through all stages from the first sight elevation of some portion of the sound midrib until through stress of internal tensions it finally split open, showing the tumor tissue in the bottom of the cleft, which tissue gradually increased in size until it projected far beyond the borders of the crevice as a typical gall. These growths developing from within outward must be due to migrations or growths from the primary tumor (of bacteria cer- tainly, of host cells inclosmg the bacteria probably), but we have not been able to demonstrate the channel of migration either in unstained or stained sections. Cuts made at various points between the primary and the secondary gall yielded nothing to the microscope, nor did we obtain bacterial colonies on agar poured plates made from such tissues, but this is not surprising considering the relative scarcity of the bacteria in the galls themselves. In the olive tuber- cle, which is superficially like the crown-gall, there are abscess cavities filled with the parasitic bacteria, and a distinct channel of infection can be traced from the primary tumor to the secondary » (metastatic) tumors. This occurs in the wood following the path of certain spiral vessels situated at the inner border of the xylem next to the pith. Here distinct lesions occur. On cross section the path of migration in the stem can be seen with the naked eye in the form of small brown dots (lines on longitudinal section) from which under very favorable circumstances a white bacterial slime may be seen to ooze in minute quantity. Under the microscope this browned area is seen to be occupied by bacteria. The vessels and 213 METASTASIS. 173 surrounding tissues in which these bacteria lie are not only stained, but otherwise disorganized. Nothing of this sort cecurs in the crown-gall. The subject is still under consideration. The anatomy of one of these metastatic tumors in a very early stage of development is shown on Plate XXX. All the central portion of the section is occupied by the incipient tumor. The white lines on the margin mark off the extent of uninfected tissue. The tumor had not yet ruptured to the surface, but would have done so in course of a few days, on the upper part of the section, where the abnormal tissue is nearest to the surface. CHEMICAL CHANGES. EXCESS OF OXYDIZING ENZYMES IN THE GALL TISSUE. The oxydizing power of extracts from crown-galls is greater than that of extracts from sound tissues. Toumey showed this for almonds. -It was also shown by Miss Marian L. Shorey in some deter- minations made for the senior writer in 1908, using sugar beets. These beets had been inoculated for some months with the daisy organism and bore moderate-sized tumors. The black powder isolated and purified by repeated precipitations with alcohol was intro- duced by knife wounds into the crown of many growing sugar beets, but no tumors resulted. This excessive production of colorless substances oxydizing readily to dark compounds on exposure to the air is to be regarded as a host reaction, and is perhaps due to an increase in the oxidase content. In 1909 (Blatter f. Ziickerriibenbau, XVI Jahrg., Nr. 6) Reinelt mentions that Bartos had observed the gall substance in sugar beet to be somewhat darker than the rest of the beet, and says that he him- self observed that when beets are placed in absolute alcohol or vapor of alcohol this difference in color becomes more pronounced, the gall becoming very dark, whereas the body of the beet is but little stained. In some tests made in 1910 the senior writer observed the same difference but only so far as regards the outer protected surface. When the galled beets were thrown into alcohol the galled parts turned dark almost immediately, while the smooth part of the root (pro- tected by a normal bark) remained white. No such contrast was observed, however, when the same beets were sliced so that the alcohol had an equal opportunity to act on all the tissues. These were the beets which served for the illustrations shown on Plate XXII. OTHER CHANGES IN THE TISSUES. The chemical analyses by Strohmer and Stift (Osterr. Ungar. Zeits. f. Zuckerind. und Landw., II Heft, Wien, 1892) show in the 213 174 CROWN-GALL OF PLANTS. crown-galls of the sugar beet, as compared with the unaffected parts of the same roots, slightly more water, considerably less cane sugar, the presence of invert sugar, double the quantity of ash, and in all but one instance more than double the amount of raw protein. Six analyses were made and the calculations are expressed in per cents of fresh substance. They all agree, except that two blanks occur in the invert-sugar line, and two in the raw-protein line. The same facts respecting cane sugar, invert sugar, pure ash, and raw protein are shown still more strikingly in a table where the amounts are calculated in 100 parts of the dry substance. No invert sugar was found in the normal parts of the roots, but 0.91 to 1.52 per cent in the galls. An average of the six analyses shows that the dry substance of the galls contained 50 per cent cane sugar as against 61 per cent in the normal parts of the roots. The average per cent of ash in the roots examined was 2.78 and in the galls 6.05. The average per cent of raw protein in the roots was 4.09 and in the galls 9.80. ANALYSIS OF FLASK CULTURES OF BACTERIUM TUMEFACIENS. Analyses of flask cultures of the daisy organism after some months’ erowth in 750 ce. filtered river water containing 35 grams c. p. calcium carbonate, 14 grams Witte’s white peptonum siccum, and 35 grams Merck’s c. p. dextrose were made for us by Dr. Carl L.. Alsberg, with the following results: Received July 26, from Doctor Smith, five flasks of the culture, labeled, ‘‘ Daisy (newest strain).’’ The reaction of the culture medium [inoculated March 29, 1910] was distinctly alkaline; the bottom of the flask contained much calcium carbonate, which was filtered off. The fiitrate was alkaline. A small portion, when acidified with acetic acid and treated with ammonium oxalate, gave a heavy precipitate of calcium oxalate, showing that a considerable amount of the calcium carbonate had been dissolved. The solution reduced Fehling’s solution powerfully, showing the presence either of aldehyde or of sugar. Subsequent investigations showed the absence of aldehyde, so that this reduction must be attributed to sugar. Other flasks of the same lot, the analysis of which was taken one or two months later, still showed a large quantity of sugar present. The filtrate, which was alkaline, was preserved and examined. It did not reduce ammonium silver nitrate solution, and therefore can not have contained any aldehyde. It gave a powerful reaction with potassium iodide, resulting in the formation of considerable iodoform. Hence, the main constituent of the distillate was ethyl alcohol. The residue in the distilling flask was now acidified with sulphuric acid, and the distillation repeated. The distillate proved to be very acid, and had an odor resembling acetic acid. It was made ammoniacal and con- centrated to a small bulk. The neutral solution resulting was treated with silver nitrate, yielding a crystalline precipitate. This was recrystallized in hot water, yielding large white needles; 0.3969 gram of this silver salt yields 0.2559 gram of silver, or 64.46 per cent of silver. Silver acetate contains theoretically 64.67 per cent of silver; hence the volatile acid can not be anything else than acetic acid. The results obtained with this single culture flask were exactly duplicated with two other flasks. 213 CHEMISTRY OF ORGANISM. 175 Another portion of the culture was acidified and shaken out with ether. The ether was driven off, leaving a yellow, oily residue which contained a very small quantity of colorless, radiating, short prisms. These were insoluble in water, and had every appearance of fat. It was attempted to discover whether the residue contained any other acids, by preparing the barium salts and fractionating them by means of abstrac- tion with absolute alcohol. No lactic or succinic acid could be detected. The resi- due from the ether seemed to consist mainly of a little fat and some fatty acids. The calcium carbonate, which remained in the flasks, was removed from the cul- tures by filtration in hydrochloric acid and extracted with ether, and no acids passed into the ether extract, so that this precipitate does not seem to have contained any- thing besides the calcium carbonate. Summary: A considerable quantity of acetic acid and ethyl alcohol was identified in the culture medium. No other fermentation acid could be detected. There seemed to be present a small amount of fat or fatty acids. THE STIMULUS TO GROWTH. All plant tumors are not due to the same parasite, but all the hyperplasias are due probably to the same chemical substance or to closely related substances, whatever the organism may be that produces these growths. This substance, which we shall eventually isolate, is probably a by-product of the growth of the intruding organism, possibly a complex colloid, or perhaps only some compara- tively simple substance acting continuously in minute quantities. It is our hope finally to cause the crown-gall with specific products of the bacterial growth freed from the living organisms and from extra- neous substances, and we have under way already certain experi- ments of this sort, but they are not yet ready to be reported on. As a first working hypothesis we have assumed some salt of acetic acid, possibly ammonium acetate, to be the cause of the stimulus, either, (1) as the primary source of the irritation, or, (2) as the liberator of such an irritant from the protoplasm of the bacteria through its killing action on their membranes, which would render them permeable. PHYSICAL CHANGES—EARLY DECAY. The physical changes in the tumors are such as would naturally occur in any rapidly proliferating parenchyma imperfectly provided with conductive tissues. It would seem that beyond a certain point the soft tissues can not be supplied with water and food, and decay sets in with more or less sloughing of the tumor and the appearance of open wounds. The harder and more slow growing the gall the later this appears. A variety of saprophytic bacteria and fungi take part in disintegrating the overgrown tissues. Among these saprophytic bacteria there are several white forms closely resembling the gall organism as grown on agar poured plates, dendritic white forms, green fluorescent species, yellow species, orange species, pink species, etc. 213 176 CROWN-GALL OF PLANTS. The nonpathogenic white forms generally develop on agar plates somewhat whiter or creamier or denser colonies than the gall organ- ism. They look more like the latter in early stages of growth than after some days. But some resemble it so closely on agar that cul- tures on other media are required. From old galls it is often difficult to isolate the parasite, the tissues swarm with such a mass of secondary and tertiary forms. So true is this that from such parts it is scarcely worth while to attempt isolations. These are best made from the youngest growing parts. Their fleshy nature also tempts parasitic fungi and bacteria, mites, nematodes, and a variety of insects. When the tumors are very fleshy decay sets in earlier than when they are woody. EFFECTS OF THE DISEASE ON THE TISSUES NOT DIRECTLY INVOLVED. PHYSICAL EFFECTS. e The necrosis of gall tissues already mentioned affords opportunity for the entrance of rain water and many sorts of insects, bacteria, and fungi, which bring about more or less destruction of supporting tis- sues not involved in the original tumor. In this way the pear-blight bacillus and facultative wood and bark parasites of various sorts may enter, causing serious stem and root injuries. If the plant is an orchard tree it may be weakened by this decay of the wood so as to be easily broken off by animals or blown over by the wind. This often occurs in the peach and almond; rarely in the apple. Plate XXXI shows the bacterial apple blight (Bacillus amylovorus) orig- inating in a hard gall. PHYSIOLOGICAL EFFECTS. The immediate and remote physiological effects of these tumors vary from species to species and also within the species and are gen- erally less pronounced and certainly less speedy than we might expect from their size and vigor of growth. The plant, however, is less specialized than the higher animals, especially by absence of a nerv- ous system, and in this connection it might be interesting to speculate on what would be the outcome of malignant animal tumors if the depressing influence of pain were removed and the consequent greater or less disturbance of all the functions of the body. | In many instances the tree shows no material injury even after a series of years. This is especially true of the apple, according to Hedgecock, Stewart, and others. In other cases, and this is true even of the apple, the attacked tree is dwarfed in comparison with its unattacked fellows. Peaches and almonds show this dwarfing to 213 EFFECT OF CROWN-GALL ON THE PLANT. 1G a greater extent than apples, and roses in hothouse culture are still more conspicuous examples of it. Unfruitfulness has also been observed in the last three species and in the grape. A large part of this phenomenon is perhaps attributable to simple abstraction of food and water. In case of the daisy this often proceeds to such an extent that individual branches projecting beyond well-developed galls present a starved appearance and die prematurely. This disease never induces premature development of blossoms and fruit so far as observed, but on the contrary retards develop- ment—rose, daisy, apple. It is a difficult matter to determine whether the substances elabo- rated in the tumors by the parasite or by the saprophytes which follow it are absorbed and act as slow poisons on the remoter tissues, but there is some warrant in the appearance of the plants for this assumption. Death of galled cuttings may occur within a few months, but ordi- narily on well-rooted plants it either does not occur at all—i. e., the the plant outgrows the disease—or it occurs only after a lingering illness of many months or several years, and then frequently as the result of secondary infections due to other organisms. In many of our inoculated daisies we have observed what we have interpreted as increased resistance due to the long-continued growth of tumors on the plants, and consequently there would appear to be reactions set up in the plant which are possibly comparable with some of those observed in the animal body. We do not yet know to what substance this increased resistance is attributable. The sub- ject is dealt with more fully in the following chapter. EXPERIMENTS SHOWING INCREASED RESISTANCE OF THE HOST DUE TO REPEATED INOCULATIONS AND ALSO DECREASED VIRULENCE OF THE BACTERIA. While the work with the different gall organisms was being car- ried on extensively, a group of plants of the Queen Alexandra daisy or progeny of the same was used constantly for inoculating, and the diminishing size of the galls that formed in comparison with those of the first inoculations and also the longer period of time required for their formation drew attention to the fact that either the organ- isms used were less virulent than when they were first isolated or else that a change was taking place in the plants themselves. To determine which hypothesis was the correct one fresh daisy galls were taken and the organism plated out to get a strain which had not become attenuated through repeated transfers on culture media. The new strain was inoculated into cuttings made from galled plants which themselves had been cuttings from previous galled ones. 78026°—Bull. 213—11——12 178 CROWN-GALL OF PLANTS. The results of the inoculations seemed to indicate that the change must be in the plant itself, for the galls that formed from the presence of this newly isolated organism were also slow growing and did not reach half the size of those galls produced when the first daisy plants were inoculated. The idea then began to take shape that this failure of the organ- ism to form a gall of the usual size when inoculated into the most favorable growing daisy tissue might be due to some substance developed in the plant for protective purposes, and experiments were planned to determine if daisy plants could be made immune to this disease through repeated inoculations into the same plant or into rooted cuttings made therefrom. In the following tests the plants used were taken at their most favorable age—that is, they were inoculated when the tissue was young and tender, so that the organism would have the best possi- ble opportunity to produce the disease. Because cuttings did not grow well in the winter months the work was confined generally to the spring and summer. (1) In March, 1907, a dozen daisy plants of the Queen Alexandra variety were inoculated with the daisy gall organism. These plants had never been known to have galls and had not been inoculated before. In two months’ time good-sized galls had formed at all the points of inoculation. (2) Cuttings (first set) were made from the preceding plants in May, 1907. The cuttings were growing well in July and then a second series of inoculations were made on them. A dozen plants were used this time. Galls formed which were as large as those of the first series. (3) In November, 1907, cuttings (second set) were made from the plants of the second series, but they did not grow well at first and it was decided to wait until growth had started up well in the spring before further work was done with them. The inoculations (third inoculations) were made in April, 1908. Galls formed at each inocu- lated place, but they were much smaller and grew very slowly. In August they were less than half the size of the galls of the first series. (4) Twenty-five cuttings (third set) were made from these diseased plants on August 17, and inoculations (fourth series of inoculations) were made November 18, 1908, on a dozen plants two and three shoots each. In the meantime a new strain of the Queen Alexandra daisy was purchased from a florist and the virulence of the organism checked up on these new plants which had never been affected with the gall. Large galls formed on the new daisies in a month, but there were none on the third set of cuttings. This was the fourth time that strain had been inoculated. 213 THE QUESTION OF IMMUNITY. 179 At the end of a month (December 22, 1908), as there was no trace of a gall starting to form, the same 12 plants were inoculated again (fifth series of inoculations) further to test the case. These plants were watched carefully but no galls formed. In a few cases the tissue at the points of inoculation was raised a little as though the presence of the organism had had some little effect. As galls formed at every point of inoculation on the check plants the organism used for the inoculations was proved to be allright. However, four months after this last inoculation of the third set of cuttings, the plants were examined again, and a gall was found on the root of one of them and one on the stem of another where a cutting had been taken. (5) In March, 1909, cuttings (the fourth set) were made from the plants which seemed to be immune, and on May 20 they were inocu- lated as follows (sixth series of inoculations), some with the daisy organism which had been used through the entire test (strain B), some with the peach-gall organism, and some with a daisy organism recently plated from a gall and proved up by other inoculations. Six to 8 shoots on each of 6 plants were inoculated with the old-daisy organism; 4 plants including a like number of shoots on each were inoculated with cultures of the crown-gall of peach organism; and 6 plants with cultures of the daisy-gall organism recently plated out. In all there were over a hundred inoculations, i. e., groups of punctures. There were no daisy plants available for controls, so young sugar- beet plants about 6 inches tall were inoculated at the crown with the same cultures. Two beets were inoculated with cultures of the old daisy, 2 with the new daisy, and 2 with the crown-gall of peach organ- ism. Sugar beets were used because they had been found to take the gall very readily. On June 18, 1909, there was not a trace of gall formation on any of the daisy plants inoculated May 20. The checks of the peach gall and of the old daisy (both on the sugar beets) had good-sized galls, but those beets inoculated with the new daisy had none. These plants, however, were in a shady place and had not made much growth since the time of inoculation. The galls on the 4 sugar beets were accounted sufficient proof that 2 of the 3 strains were able to produce galls in susceptible plants. The same day (June 18, 1909) some of the same daisy plants were inoculated again with the crown-gall of peach organism, 16 groups of punctures being made (seventh inoculation). The plants were growing very well. Five young sugar beets were inoculated at the crown with the same cultures as checks on the daisies. On July 6, 1909, the plants were examined and no galls were found on the daisies; 2 of the 5 sugar beets had small galls which bade fair to increase in size as the beets grew. 213 180 CROWN-GALL OF PLANTS. This last set of cuttings (fourth set) in which two sets of inocula- tions had been made already was subjected to one more test. A fresh strain of the peach-gall organism which had been isolated in April, 1909, from some trees grown in Virginia was used for these inoculations. This organism was selected because it had produced galls very rapidly on a daisy plant which had never been affected with this disease. In July, 1909, 43 inoculations (eighth series of inoculations) were made. Five young sugar beets were inoculated at the crown with the same cultures used on the daisies. On August 30 the last inoculations of the daisy were examined and no trace of a gall was found on any. Of the 5 sugar beets only 1 had a gall; the beets had grown scarcely at all since they were inoculated, so they were repotted and left to develop. October 4: These beets never grew to any extent, but 1 other bore a tiny gall. On September 20 all of the plants included in the fourth series of cuttings were taken from the pots; the soil was washed from the roots, after which they were examined thoroughly. Four out of the 16 plants bad galls on the roots, only 1 of which was of any appreciable size. (6) Cuttings were again made, this being the fifth set from the original galled plant. For checks, new daisy plants of the Queen Alexandra variety were purchased from a Boston firm and grown under the same conditions, so that both sets of plants would be about the same age when inoculated. A fresh strain of the daisy organism was obtained in November, 1909, by plating from a gall, and inoculations were made December 1 on 31 of the supposedly resistant cuttings which were growing well and on 16 of the new daisies from Boston never before inoculated to be held as checks. The first subcultures from the poured plate colonies were used for the inoculations. On December 14 (two weeks’ time) galls had formed on 14 out of the 16 daisies of the new strain, but none whatever on the resistant strain. On December 21 a gall had formed in one of the resistant cuttings; it was very tiny, but unmistakably a gall. By this time (end of third week) galls had formed on all the check plants and were from - half an inch to an inch in diameter. On January 6, 1910, 14 out of the 31 resistant cuttings had small galls starting to form. Some of these were merely a slight swelling. This was thirty-seven days after inoculating, and it will be remem- bered that all but 2 of the check plants had galls within two weeks. On January 18 (forty-nine days) the supposed resistant cuttings were examined again and 23 of the 31 found with galls. None of the galls were larger than a small pea, however. 213 THE QUESTION OF IMMUNITY. 181 On February 9 all of the resistant cuttings had small galls, except 4, and 2 of these showed indications of swelling. This was seventy days after inoculating, and nothing comparable with this has been known to follow the inoculations of a daisy plant which had never before been inoculated with the gall organism. The beginnings of gall formation have been seen on daisy as early as the fifth day after inoculating, but the usual time for decided evidence is ten days or two weeks and always within three weeks. On March 10, 1910, galls were forming on the 4 resistant cuttings which were still free from galls on February 9. In July, 1910, all of the resistant plants bore large galls, i. e. erowths 14 to 2 inches in diameter.* (7) Cuttings were made from these plants in August, 1910 (sixth set), and inoculations were made on these in November, December, and January, after they were well rooted and growing rapidly. The results are not yet ready to be reported upon. So far as we have gone, loss of virulence may account for some of our failures to infect, but not, it would seem, for all, since in some of the experiments already described the check plants contracted the disease promptly, while the others did not. The results now under way ought to settle the question. The following results are believed to be due, in part at least, to loss of virulence, but in part also to increased resistance. The weak point in the reinoculations is the almost complete failure of the checks. In September, 1909, about 200 rapidly growimg young daisy plants (rooted cuttings from old plants) were inoculated in the top of the shoot with young slant agar cultures of the old daisy gall organism (strain B). No galls resulted. Thinking this complete failure might equally well be attrtbuted to increased resistance on the part of the plants, since all of the cuttings had been taken from plants already twice and thrice successfully inoculated, the plants were repotted, top pruned, forced into rapid growth, and reinoculated. The first reinoculations were on December 6, using young agar sub- cultures from several typical-looking colonies recently derived from a daisy gall by Miss Lucia McCulloch. The bacteria were pricked in. A small part only of the plants were inoculated. Checks were kept. All failed. On December 13 to 17 the entire 200 plants were reinoculated by needle pricks, rather more than 400 groups of punctures being made on young branches. For this purpose young agar subcultures were used. They were derived from a colony recently isolated from a , @ A comparison of No. 6 with earlier results seems to indicate that even when first isolated from a gall some colonies are more virulent than others. 213 182 CROWN-GALL OF PLANTS. daisy gall by Miss Brown and believed to be the right thing because it behaved typically on agar. The inoculations were made by the senior writer, assisted by Miss Bryan. Five days were devoted to the work, and, as 85 check plants were held, interesting results were anticipated, but no galls ever formed. The check plants (with two exceptions, 1020 and 1056),* also remained free, although they were in a growing condition and derived from plants never before inocu- lated and not long in the hothouse. The experiment must, there- fore, be set down as a lost one without knowing quite why. Prob- ably the failure must be ascribed to the use of a nonvirulent colony. The plants stood in 10-inch pots, occupying the whole of a 125-foot, well-lighted greenhouse bench, and made throughout a good growth. They were of two susceptible varieties. When the final examination was made in August, 1910, the plants were large and had been in bloom all summer. Occasional shoots showed a slight knobbiness where the needle pricks entered, and often there was more than the usual amount of corkiness in the pricked areas, but not a single tumor resulted from the inoculations. That these plants were still subject to infection (given a sufficiently viru- lent organism) is indicated by the fact that 13 of them bore natural tumors on the stem at the surface of the earth. Six of these tumors were large; the others were less than 1 inch in diameter. The par- ents of all of these plants (about 21 large daisies) all bore similar natural (and large) tumors on the base of the stem at the time the cuttings were made, and, as already stated, the plants from which they in turn were propagated had been (they or their progenitors) several times artificially imoculated with the production of galls. Cuttings were now made (August 5, 1910) from a large number of these plants for a second large experiment, and cultures were plated from the most favorable looking (youngest) of the 13 knots, with a view to obtaining a more virulent strain with which to make subse- quent inoculations. In November, December, and January inoculations were made on | these plants as follows: (1) With subcultures from a colony on a plate poured from the most favorable of the 13 tumors just mentioned. (2) With subcultures from a colony on a plate poured from a daisy tumor occurring on a ‘‘nonresistant”’ plant. Both these sets failed to produce tumors. Not only was this true of the ‘‘resistant”’ plants, but also of the check plants never before inoculated. (3) Isolations were now made from a gall growing on one of Miss Brown’s resistant plants (sixth series), and subcultures from two of a These had very small galls in the inoculated places at the end of a year. 213 LOSSES DUE TO CROWN-GALL. 183 the colonies thus obtained proved to be actively virulent. When these were inoculated into the control daisies tumors soon appeared and are now growing rapidly. Numerous ‘‘resistant’’ plants were inoculated at the same time. All of these have developed small hyperplasias; but it is too early for comparative statements, and furthermore a correcter test, and one we have not yet been able to make (owing to the failure mentioned above), would be to inoculate checks and resistant plants with a virulent organism taken from a tumor on some plant which had never before borne tumors. This would remove the possibility of a heightened virulence in the organism used. LOSSES DUE TO CROWN-GALL. In consideration of the slow progress of this disease on many ioculated plants, the question has arisen whether crown-gall is really a serious disease or only to be regarded in the light of a minor dis- turbance, i. e., something comparable to warts or benign tumors in the higher animals. Inasmuch as our exact experiments have not continued in all cases for a long enough period of years to give comprehensive results the most that can be done here in many instances is to summarize the opinions of growers and others who have given most attention to the disease as it prevails in the field, supporting these as best we may with our own observations, already detailed, in great part. THE DAISY. The plants are dwarfed and disfigured but only rarely killed out- right or at least not for a long time. They are more or less stunted according to the size and rapidity of growth of the gall. Cuttings are injured worse than old plants. The New Jersey grower mentioned earlier is the only one who has made complaint to us. THE ALMOND, THE PEACH, AND OTHER STONE FRUITS. Toumey described this disease as serious on the almond in Arizona, and showed photographs of a 40-acre orchard ruined by it. Speaking of this orchard, he says: In the Glendale orchard some of the trees were diseased when planted. The actual number, however, that had galls upon them was very small. After the expiration of eight years, less than 1 per cent remained unaffected. * * * With each succeeding year a greater number of trees died outright or broke off at or just beneath the surface of the ground, where developing galls had gradually weakened the stem. A very conservative estimate would place the losses in this one orchard at at least ten thousand dollars. Probably the losses to the deciduous fruit and grape growers of Arizona from this disease amounts in the aggregate to from forty to seventy-five thousand dollars annually. 213 184 CROWN-GALL OF PLANTS. In reply to an inquiry, F. H. Simmons writes as follows (1910) con- cerning crown gall in Arizona: There were 40 acres in the tract [probably Glendale orchard described by Professor Toumey]. I think they were set in the fall of 1889, and I took charge in 1899. The crown-gall was very bad on them, and in spring of 1897 there were cut and gathered three wagonloads of the gall. The trees were treated with bluestone on all cut sur- faces. This treatment was followed up each year with less galls until spring of 1902 there was less than a bushel basket of galls cut. The drought by this time having made inroads on the trees the treatment was abandoned and part of the orchard pulled out, scarcely a gall being found. * * * Trees badly affected seemed to have lost power of growth. There were practically . on the mesa 125 acres in all. With the exception of 10 acres, all the orchards were badly affected, and about the year 1900 were practically out of business as a paying proposition, and have been nearly all pulled out. Selby, of Ohio, reported to Toumey as follows: From observations made in Ohio there seems no reason to believe that peach trees affected with crown gall at transplanting age will ever come to successful fruiting. Te) Ce RE One orchard in Lawrence County, containing 200 trees purchased in New Jersey, was grubbed out at seven years of age without having borne a single profitable crop, although other trees of like age situated near them had yielded fruit. These trees were badly affected when delivered, and were nearly all of them diseased at the time of removal. * * * Another parallel case occurred in Ottawa County. In 1908 Selby made the following statement: I do not recall a single instance out of many observed and recorded in which, the tree surviving transplanting, the removal of the galls by excision served to prevent the formation of new galls upon the same tree. Excision appeared to exert no influ- ence whatever in the way of suppressing the trouble, and this irrespective of the loca- tion of the excised galls; whether but a single gall upon a small root or more than one gall on stem or root or both were removed and the wounds rubbed with sulphur, the new galls constantly appeared later. This may be taken as showing a diseased tendency of the plant tissues and this condition, this diathesis as it may be called, can scarcely contribute to the longevity of the tree independent of cutting off the water supply. Earle reported to Toumey as follows: Crown-gall is very abundant in Alabama on the peach and is sometimes found on the plum. I consider it a very serious peach disease in Mississippi and Georgia, as well as in this State. In 1892 Wickson, of California, wrote as follows: For some time many nurserymen followed the practice of removing the knots from the trees as dug from the row, but this was abandoned when it was found that the knot commonly reappeared after planting in the orchard. At present no reputable nurseryman sells such trees; they are burned at the nursery. Probably during the last twenty years hundreds of thousands of such trees have spindled and died in the best soil and with the best treatment. Woodworth, of California, reported to Toumey as follows: The crown gall occurs in California on all our deciduous fruit trees and on grapes. It has been abundant and serious. 213 LOSSES DUE TO CROWN-GALL, 185 Toumey wrote: In California, where the fruit industry is many times what it is in Arizona, the losses must be correspondingly great. In Pennsylvania on fruit trees in the nursery, according to Butz (Ann. Rep. Pa. State College, 1902, p. 405): There is little warning of the presence of the disease in a block of trees while they are developing into salable stock, but when they are taken up it is frequently dis- covered that from 20 per cent to 80 per cent of them are affected at the roots with crown- gall, rendering them unsalable. Butz also cites from correspondents as follows: We have known peach blocks in New Jersey to be entirely destroyed. * * * One year ago we had it bad in peach and threw away thousands. APPLE TREES. Whitten, of Missouri, reported to Toumey as follows: I have seen it on a few apple trees in the nursery, but it was not severe enough to impair their growth. Concerning the injury done to orchard trees, Butz has the fol- lowing as the result of one of his experiments. On November 21, 1898, 11 apple trees were planted upon the station grounds. These trees were donated by a Pennsylvania nurseryman, and all of them bore galls at the crown varying in size from a hickory nut to an unhulled walnut. The root system of these trees was apparently most excellent, having an unusual amount of fibrous roots. But owing to the fact that these fibrous roots proceeded mainly from and about the galls it was evident that the galls were the inciting cause of the unnatural development. The trees were three years from the graft, and but for the galls were excellent trees for planting in the orchard. Five of these trees were York Imperial and six were Ben Davis, the two varieties of apple which are most susceptible to crown- ‘gall and the most extensively propagated and planted in Pennsylvania. Records taken in April, 1901, after the trees had made two seasons’ growth, show immediate injury due to the galls. Two trees of York Imperial had died, and the other three had made only weak and slender growth. * * * Of the Ben Davis trees, all grew, though the growth made was in all cases short and weak. The length of the best shoots made in the second season varied from 4 to 10 inches. After another year’s growth these trees are still living, making some new wood each year, though it is not as strong as it should be. An examination of the galls at the roots (June, 1902) by removing the ground about them shows that they are increasing in size, and in some cases more completely girdling the trees than when they were planted. The effect of this gall development is shown in the heavy production of sprouts from the stock roots below the gall and the consequent weakness in the grafthead. * * * A peach grower in Franklin County in Pennsylvania is now having a similar expe- rience with peaches. He wrote me in November, 1900, that he suspected something wrong with a block of 1,000 peach trees in an 80-acre orchard, and digging at the roots discovered an enlargement which was identified at this station as crown gall. The trees came from an Alabama nursery and were planted in the spring of 1899. The growth during the first two years was excellent, but now as the trees reach fruiting age they indicate a weakness that can not be overcome. 213 186 CROWN-GALL OF PLANTS. He also cites from a correspondent as follows: It is more prevalent in apple than in anything else. On the block of apple trees which were 2 years old when you were here, we did not find a single tree affected, while on our trees, now 2 years old, we find 30 to 40 per cent affected with crown- gall and we will sustain a big loss. At the time these 2-year trees were grafted, I grafted 30,000 for a neighbor for his own orchard planting and on the trees taken up he has found but 2 or 3 per cent affected, though the source of stocks and grafts was the same. This looks as if the disease was in my ground. The conclusion of this nurseryman is entirely correct; the cause of the disease is in his ground. A former colleague, Mr. P. J. O’Gara, who has had a very wide experience on the Pacific coast, has observed the disease to be seri- ously injurious to Spitzenberg apples in Oregon, and also to pears, dwarfing the trees and reducing the size of the fruit. He states that hold-over blight (Bacillus amylovorus) is very apt to find lodgment in the galls when they occur above ground and that root-rot begins commonly in the galls when they are underground (oral communi- cation). He is also our authority for the statement that crown-gall has seriously injured peach growing in Colorado. The disease seems to be worse in dry climates, where irrigation is practiced. In 1910, after conversation with Mr. O’Gara, the following letter was received from him: I am inclosing a photograph of crown-gall (hairy-root type), taken in my office at Medford, Oreg. This tree is 7 years old, but is no larger than a good 3-year old and certainly not so vigorous. This tree is exactly like 50 trees in the same apple orchard, the variety being Esopus Spitzenberg. Crown-gall, either hairy, hard, or soft types, certainly injures apples if the infection starts with the seedling or the graft. Ifa tree is several years old before becoming infected, serious injury is not so liable to be the case, as the vigor of the treesomewhat counteracts the effects of the gall. But Spitz- enberg apples infected on bodies or crowns often become so ‘‘warty” that growers cut them out. Besides, crown-gall above the ground always permits the entrance of fungi, and in susceptible varieties like Spitzenberg, Bacillus amylovorus gets in its deadly work through the gall. Anyone having experience on the Pacific coast knows that a crown-gall above the crown of a Spitzenberg means blight infection sooner or later. Later Mr. O’Gara sent on a blighted apple limb from Medford, Oreg. (Pl. XX XI), with the following note: I am sending you under separate cover a specimen of Spitzenberg apple limb which has a bad crown-gall, through which pear blight infection entered. Crown- gall on the body or crown of a Spitzenberg apple is very dangerous, from the blight standpoint. The past year I have seen hundreds of blight infections through these galls. For this reason every crown-gall must be removed, and our inspectors enforce this regulation to the letter. In 1898 Selby cited the case of a grower of nursery stock who found part of a block of apple trees badly affected with gall about the year 1893. The trees were dug up and the ground left to rest a year, 213 LOSSES DUE TO CROWN-GALL. 187 then peach trees were planted. In that portion where the apple trees had been diseased most of the peach trees became affected with galls, and were worthless. Quite opposite views are expressed in the following citations, the first one of which is from Mr. F. C. Stewart, of the experiment station at Geneva, N. Y. (Proc. 53d Ann. Meeting, West. N. Y. Hort. Soc., Rochester, Jan. 22 and 23, 1908, p. 98): In this connection it should be mentioned that the crown-gall of apple, although resembling crown-gall of peach and raspberry, is an entirely different thing.¢ There is abundant proof that the apple crown-gall is not communicable from one tree to another. Moreover, in New York, at least, apple crown-gall is an unimportant disease. Although common in our nurseries, it is rarely found in orchards. In 1899 C. H. Stuart & Co.,o Newark, N. Y., set out an experimental orchard of 500 trees, mostly Baldwins, all affected with crown-gall. The trees have now been set nine years. Under date of January 20, 1908, Mr. Stuart writes as follows: ‘‘These trees to-day show as good a growth as the trees planted the same time and free from crown-gall. The bark is smooth, healthy in appearance, and the trees look thrifty and vigorous.”’ An experiment made by the station bears on this point. In 1901 we planted 22 apple trees affected with crown-gall to determine the effect of this disease upon the growth of the trees. The trees were 3 years old. The galls varied in size from 1 to 2 inches in diameter and were located mostly on the taproot, but in a few cases on lateral roots. Some of the trees had several galls each. We believe the galls were typical of those commonly found on apple trees in New York nurseries. Five of the trees were dug in 1903, 5 in 1905, and the remainder in 1907. In no instance was there any evidence that the galls had increased in size or number, or that they had been in any way injurious to the trees.¢ Probably apple trees bearing large galls should be rejected, but unaffected trees from the same lot may be planted without fear of bad results. Mr. Barden also writes as follows to Mr. George G. Atwood, chief bureau of horticulture, Albany, N. Y., concerning this same orchard: Referring to yours about crown-gall on nursery trees that have been planted in orchard for several years, I would say that the Stuart orchard on the Bailey farm 3 miles north of Newark is the only one that I have had any knowledge of. In company with Mr. Stuart I drove to this farm last fall [1909] and carefully studied the different trees, every one of the 400 @ having heen planted with a large crown-gall onit. These trees have now been planted eight years, and, with the exception of a few that were girdled by mice several years ago, are in a vigorous and healthy condition. The growth has been even, no stunted trees, and it would certainly he hard for an orchardist to condemn a tree on account of crown-gall after seeing this orchard. Doctor Hedgecock also regards crown-gall as of small consequence to the apple, especially if the root-grafts are well made. His field experiments on the apple have been extensive (mostly in the Missis- sippi Valley), and cover a period of five years. Mr. Giissow has expressed similar views. @ See note under raspberry. b Nurserymen. ¢ The location of a gall perhaps may determine its injuriousness, i. e., whether on crown or root. Butz’s trees bore galls on the crown. So far as known, no comparative orchard tests have been made. d Five hundred in Mr. Stewart’s statement. Were 100 lost during these years? And ifso, how many by erown-gall? No checks appear to have been held for comparison. 213 188 CROWN-GALL OF PLANTS. THE QUINCE. The galls of the quince (Cydonia vulgaris) occur on the stems, and are warty in appearance. Often an entire limb will be covered by these broad irregular outgrowths. Whole orchards in California have been attacked by these galls and quince trees in other western States are known to be affected. Mr. Hedgecock has received dis- eased specimens also from Ansted, W. Va. Doctor Trabut sent speci- mens of quince gall from North Africa (Pl. XXXV). Lounsbury reports a quince gall which appears in the form of ‘‘rough, lumpy growths” as common in South Africa. THE RASPBERRY AND THE BLACKBERRY. The disease appears to be quite prevalent on the red raspberry in various places in the United States, and must be regarded as injurious, although some nurserymen are of a contrary opinion. The extent of injury to black raspberry and to the blackberry is not known. Mr. P. J. O’Gara has observed one apple and pear nursery in Oregon where practically all of the young trees were galled. This nursery was set on the site of an old berry patch in which the crown-gall had prevailed (verbal communication). The following similar statement is taken from the report of the Dominion Botanist (Giissow) (1 George V, Sessional Paper No. 16, AeAOLY; p2 2738)< One prominent grower had a small area planted with raspberries. These on being taken up showed many “‘root galls.’” The plants were destroyed and no specimens were sent us for examination. The grower then planted a large area to young peach trees, the rows of which passed through the land formerly occupied by the raspberries on which the root galls were discovered. He then observed that the peaches grow- ing on this latter area were not doing well and finally failed, while all the other trees did exceedingly well. On taking up the failing peach trees, their roots showed plenty of root galls, while the others growing outside the raspberry area were free from it. The same facts were recorded by other growers. There could hardly be given a more typical example of an infectious disease. But, unfortunately, we were not acquainted with any of these observations until it was too late to make any investi- gation. If these facts as related are correct, and we have no reason to doubt them, there is still a considerable amount of research necessary. Selby is on record as long ago as 1898 to the same effect. He says that 16 per cent of some healthy peach trees planted in a badly galled raspberry plantation became affected with the gall. Wulff’s statements (Studien iiber heteroplastische Gewebewuche- rungen am Himbeer- und am Stachelbeerstrauch, Arkiv fiir Botanik, Bd. 7, No. 14, Upsala, 1908) are equally explicit. He says respecting the appearance of the raspberry gall in a garden near Karlshamn (South Sweden): On an area of 33 by 4 paces were about 100 raspberry bushes, all very badly affected by the disease. * * * From the time of their planting in 1901 to the summer of 213 LOSSES DUE TO CROWN-GALL. 189 1907, inclusive, the bushes were always sick, and have during the whole time borne either no fruit whatever or a very scanty crop. These plants were an ever-bearing variety from Denmark. In August, 1907, Wulff also found a bad outbreak of the disease in middle Sweden near Orebro: Here about 800 bushes of Red Hornet and about 100 of Superlative were attacked. The first-named bushes were planted in 1901, had borne very well during the first years, and appeared entirely normal. In 1906 the first symptoms of the disease were discovered, and in consequence of this no crop was borne in the summers of 1906 and 1907. In the next paragraph Wulff speaks of the disease as “‘very inju- rious to raspberry culture’ everywhere in Sweden where it has appeared. He also brings forward evidence to show that frost injuries have nothing to do with its appearance, and cites similar statements by Blankenhorn and Mihlhauser (vide Sorauer I, 596) with respect to the grape gall. Wulff’s own statement is: Bei meinem Untersuchungen der Himbeerkallose habe ich niemals auch nur die geringsten Andeutungen von Frostbeschadigungen entdecken kénnen. Concerning the origin of the disease neither in this paper nor a second one (Weitere Studien tiber die Kalluskrankheit des Himbeer- strauches, Arkiv fiir Botanik, Bd. 8, No. 15, Upsala, 1909) does he reach.any positive conclusion, other than that he has not been able to find in the fresh overgrowths any parasitic organism and is inclined to ascribe them to excessive nitrogen nutrition and excessive water supply. Lawrence (Some Important Plant Diseases of Washington, Bull. No. 83, 1907) shows a very interesting figure of blackberry canes split open by the growths arising from within and says that in the State of Washington the disease is very destructive to the Snyder, and that occasionally Kittatinny and Himalaya Giant are badly infected, while Erie, Early Harvest, and Evergreen are not seriously injured. He has also biaerisd the disease to be severe on the red raspberry, especially the form growing on roots and crowns. Giissow has attributed a gall on the blackberry in England to a fungus, Coniothyrium tumefaciens n. sp. THE ROSE. Occasionally the disease is very prevalent on the roots of roses grown in the hothouse, and skilled gardeners are generally of the opinion that the galls are seriously injurious, reducing the size of the plants, the amount of foliage, and the vigor of the flowers. Here again exact comparative studies are wanting. It must be obvious, however, in the case of a small plant like the hothouse rose, that the 213 190 CROWN-GALL OF PLANTS. energy used up in the production of the galls, which are often large, must be abstracted from the general needs of the plant, which as a result must either yield an inferior product or blossom for a shorter period. The following statements were received in 1909-10 from a rose grower who had much of the gall in his houses: Our houses of 10,000 plants seem all to be affected, and it looks [October 23] as though we would have to throw the plants out. The disease was definitely identified as crown-gall by the writers, who received numerous well-developed specimens (Pl. XX, fig. 2) and recommended substitute crops. Nematodes were not observed. This man was asked later in the season for more definite information concerning his losses and replied as follows: Replying [February 22] to yours of 16th instant, would say that after consultation with other growers of roses who had had experience with crown-gall and eelworm, we decided to keep our plants in and get what we could from them, rather than take a chance on some other crop so late in the reason. All the plants are affected more or less—some not as bad as others—while perhaps 200 or 300 have been killed outright. The great loss is shown when we come to cut the buds. Ata time when we should have been cutting 1,500 to 2,200 a day, we were cutting but from 400 to 600, and the average loss for the season thus far has been on a conservative estimate 67 per cent. We will cook our soil this year and hope for better results another season. In December, 1910, this grower wrote as follows: Replying to yours of 9th instant, would say we did cook our soil last spring, as we wrote you we should, and that we have had no trouble with crown-gall this season. Our plants are very fine this year, and we have been cutting some very fine blooms. Just now we are off crop, but plants are breaking in good shape and the future looks very promising. Our commission house sent us word early in the winter that they had not seen finer specimens of Bride outside of the flower show than the ones we were shipping. THE GRAPE. European observers have generally regarded the scab of the grape as a serious disease. Delacroix (1908) states that the attacked shoots grow feebly for a year or two and then the parts above the galls dry out and die. The statement of Cavara respecting rachitic growth has already been quoted (p. 15). In Italy, in 1906, in the Po Valley (near Modena), the senior writer saw cases of rogna on large vines and was informed by competent viticulturists that the disease was becoming more and more prevalent, mostly on the flat irrigated lands, but to some extent also in the hills, and that the life of an attacked vine seldom extended beyond four years. In sections of Italian rogna of the grape preserved in 10 per 213 LOSSES DUE TO CROWN-GALL. 191 cent formalin the senior writer saw bacteria in the browned outer crevices much like those described by Cuboni (1.50.3 to 0.5 yw), but less numerous and not likely to be the parasite. RED CLOVER. Galls have been found on roots of red clover (Trifolium pratense) in Kentucky and Alabama. It is not yet known how destructive this organism is when it gains entrance to a clover field. ALFALFA. Roots with tubercles other than the nitrogen-fixing nodules have been found on alfalfa plants (Medicago sativa) in Kentucky, Mary- land, Pennsylvania, Alabama, and New York (?). The galls are found on plants in fields where the stand is very poor and also an occasional gall is found on plants in very good fields. The plants affected do not grow to full size, but it is not yet known whether they are killed directly by the work of the gall organism or not, although large portions of fields die and the roots are found more or less affected with galls. COTTON. The crown-gall of the cotton plant (Gossypium sp.) occurs rarely (so far as our information goes) and is not known to cause any trouble whatever to the growers of cotton. It has been found in Texas and also on the crown of cotton plants growing in the green- house in Washington. HOPS. The reports of hop growers on the Pacific coast indicate that ‘this disease may do considerable damage, particularly as the galls often reach a diameter of one’s double fist. Some believe that an attack of two years’ duration is sufficient to kill a plant. According to Dr. W. W. Stockberger, of this Bureau, the disease occurs on hops not only in Washington State and Oregon, but also in the Sacramento valley in California: ‘‘There I have seen acres of hops in which scarcely a hill could be found which did not show these tumors, some of them being larger than my fist.” SUGAR BEETS. A crown-gall also occurs naturally on the sugar beet both in this | country and in Europe. While rather rare in the United States, it appears to be widely distributed, and more common some seasons than others. We have received specimens from localities as widely separated as Virginia, Michigan, South Dakota, Utah, California, 213 192 CROWN-GALL OF PLANTS. and Washington State. In general it is easily distinguished from the attacks of nematodes (PI. IV, fig. 1). It is less easily distinguished from what we have called tuberculosis of the beet. The latter occurs in Kansas and Colorado. It appears to be most prevalent in Colorado where at least one field was badly injured. According to one of our correspondents it is on the increase. Should this digease become widespread the yield of sugar would be greatly reduced. Crown-gall seems to be rather infrequent in Germany, judging from Dr. Reinelt’s paper in Blitter fir Zuckerriitbenbau (Berlin, 31 Marz, 1909), since with the assistance of various sugar-beet men he obtained only 47 specimens for his studies. According to Dr. Kglpn Ravn, of Copenhagen (oral communica- tion), the gall occurs on sugar beets in Denmark, but does not injure the crop, only about one beet in a million showing it. Of 3,247 beets dug in November, 1910, in Virginia (Arlington Experimental Farm), 5 bore tumors. The galls on the beet often grow to large size, e. g., Reinelt men- tions some as large as a child’s head or larger (weight 1.5 kilos), others which caused thickenings of the whole or a great part of the root, and still others which were small as peas, but set close together over the whole surface of the root. This gall we believe to be due to the crown-gall organism. Three times prior to 1910 typical looking colonies on agar poured plates were obtained from the interior of beet galls from California and once from Virginia. The Virginia colonies were not transferred to sub- cultures, and the two or three colonies selected from the California plates proved nonpathogenic to sugar beets; no additional oppor- tunity for making poured plates occurred until November, 1910. (See pp. 81-85.) Reinelt failed to isolate bacteria from the inner tissues and comes to the conclusion that bacteria are not present. He used various sorts of gelatin media. His technique of surface sterilization appears to have been proper and the source of his failure appears to have been (1) that he selected improper material (too old), (2) that he did not wait long enough for the bacteria to appear on his plates, or (3) that he diluted his infectious material too much. The period the plates were under observation is not stated. He should have held his plates for at least ten or fifteen days; he should also have mashed up the fragment of beet and inoculated copiously from the first tube, whereas he did not crush his material but only allowed the small cube to remain in the bouillon for a short time and then made his inoculations from a third transfer (third tube). Judging from our own experiments, on daisy galls, the third tube of bouillon prepared in the manner he describes would ordinarily contain very few living 213 GALL ORGANISM SCARCE IN TISSUES. 193 bacteria—often none, or less than 1 per loop (see p. 168).% If he had mashed his cube in the first tube of bouillon, allowed the con- tents of the crushed cells to diffuse for an hour, and then inoculated directly from this first tube, rather copiously, e. g., with several 3 mm. loops of the fluid, he would probably have had colonies of the @ As the result of poured plates made in 1910 by Lucia McCulloch, using a sound old hop gall received from the Pacific coast, it would seem that there were less than 500 living bacteria per cubic inch of the mate- rial used. The right organism was plated out and tumors obtained with it on sugar beet and daisy, but two of the three colonies selected were noninfectious. Plates of +15 nutrient agar, poured by Miss Brown in the fall of 1910 from tumors on sugar beet, gave the following results: (1) First set of Arlington (Va.) plates. Two c. c. of a rather old and tough tumor were mashed in 10 c. ec. of bouillon. Eleven plates were poured, all from the original tube, inoculating as follows: 3 plates each five 3 mm. loops. 3 plates each four 3 mm. loops. 2 plates each three 3 mm. loops. 2 plates each two 3 mm. loops. 1 plate one 3 mm. loop. Five favorable colonies appeared on this set of plates. (2) Second set of Arlington (Va.) plates made from another tumor—material good. Three c. c. were mashed in 10c.c. of bouillon. Eight plates were poured. The first six were from the original tube, the other two from the first dilution. The inoculation was heavy, viz: 2 plates with five 3 mm. loops. 2 plates with four 3 mm. loops. 2 plates with three 3 mm. loops. 1 plate with three 3 mm. loops. 1 plate with two 3 mm. loops. Fifteen favorable colonies appeared on this set of plates. (3) First set of Blissfield (Mich.) plates. Of this tumor 3.4 ec. e. were mashed in 10 ce. c. of bouillon. Eight tubes were poured, the first six from the original tube, the other two from the first dilution, inoculating as follows: 3 plates each with three 3 mm. loops. 2 plates each with two 3 mm. loops. 1 plate with one 3 mm. loops. 1 plate with two 3 mm. loops. i plate with one 3 mm. loop. Five colonies resembling gall colonies came up on this set of plates. (4) Second set ‘of Blissfield plates (same tumor, next day), using 0.5 c. c., which was mashed in 10 c. e. bouillon. Eight plates were poured, all from the original tube, inoculating as follows: 4 plates each with four 3 mm. loops. 1 plate with three 3 mm. loops. 1 plate with two 3 mm. loops. 2 plates each with one 3 mm. loop. No gall colonies appeared on this set of plates. (5) First set of Fairfield (Wash.) plates. A smooth tumor 3.5 to 4cm. in diameter was selected and about one-half of it (possibly 10 c. ec.) was mashed in 10 c. c. of bouillon for the plates. All of the eight plates were poured from the original tube, inoculating as follows: 5 plates each with five 3 mm. loops. 2 plates each with four 3 mm. loops. 1 plate with two 3 mm. loops. No gall colonies appeared. (6) Second set of Fairfield plates (same tumor), About one cubic centimeter was mashed in 10 c. ¢. of bouillon. Eight plates were poured, all being inoculated copiously from the original tube, viz: 4 plates each with five 3 mm. loops. 2 plates each with three 3 mm. loops. 2 plates each with two 3 mm. loops. Four colonies looking very much like the gall-forming organism grew on these plates. (7) Plates were also poured in December from a gall on another Arlington beet which had been trans- planted to the hothouse for six weeks. These yielded only one colony resembling Bacterium tumefaciens, and this gave no positive result when inoculated into sugar beets. Of these 30 colonies, as already stated, only 5 have proved infectious and all of them are possessed only of feeble virulence. (For a quantitative study made by the senior writer in November, 1910, see under ‘“‘ Sugar beet,”’ p. 81.) 78026°—Bull. 213—11 13 194 CROWN-GALL OF PLANTS. gall organism in all of his plates, provided nothing was wrong with his culture medium or the galls themselves were not too old. We have not used gelatin media for isolations from galls, but ordinary +15 peptonized beef-bouillon agar. Dr. K. Spisar has also investigated the sugar-beet gall and reaches the conclusion that it is not due to animal or plant parasites of any sort (Zeits. f. Zuckerind. in Béhmen, Prag., Aug., 1910). Bacteria do not occur in all the galls and with those he cultivated out he could not reproduce the disease. He, therefore, ascribes it to wounds, but does not advance any satisfactory reason why it should arise in some wounds and not in others. Since the above paragraphs were written we have plated what we believe to be the right organism from natural tumors on the sugar beet and with subcultures therefrom have obtained small slow-growing galls on beet (Pl. XXXVI, fig. 1), tomato, and daisy. Most of the colonies tested were noninfectious. TUBERCULOSIS OF BEETS. In the autumn of 1910 beets from Colorado and Kansas were found commonly attacked by a yellow schizomycete capable of causing cells to proliferate in a nodular growth. On section the attacked parts showed as small, water-soaked, brownish areas (Pl. XXXIV, fig. 2). Under the microscope great numbers of bacteria were observed therein and the center of the spot was seen to be disor- ganized into a small cavity. Often the surface of the nodules bore small central radiating fissures (Pl. XXXIV, fig. 3). The appearance of these cracks suggested the possibility that they preceded the infection. In some instances these brownish areas of softening were traced from the galled portion of the beet into the ungalled part. The diseased parts appeared mucilaginous—stringy when touched. This disease, which was at first supposed to be crown gall, is only superficially like the latter, because, as in the olive tubercle, the bac- teria are abundant and easily detected and produce areas of softening and central cavities. The disease has been reproduced on sound sugar beets in the department hothouses by pure-culture inoculations (subcultures from poured plate colonies). From these artificially produced tubercles the organism has been reisolated and successfully reinoculated into other sound beets. Up to this time cross-inoculations on other plants (daisy, tomato, etc.) have failed. Description of Bacterium beticolum n. sp—This organism, which may be known as Bacterium beticolum n. sp., is a rod with rounded ends, single or in pairs, chains or clumps. Clumps and chains fre- quently occur, especially in pellicles. It measures about 0.6 to 0.8 213 TUBERCULOSIS OF SUGAR BEET. 195 by 1.5 to 2.0y. It is flagellate by means of several polar flagella. No spores have been observed. It hasacapsule. It liquefies gelatin slowly, but not Loeffler’s blood serum. Gelatin stabs at 18° C. required a month for complete liquefaction. It reduces nitrates. It grows readily in peptonized beef-bouillon containing 9 per cent sodium chloride. In ordinary peptone bouillon there is uniform clouding and a copious pellicle, which falls easily. It is killed in beef-bouillon by 10 minutes’ exposure in the water bath to 51°C. It grows at 37° C., but not so well as at room-temperature (bouillon). It also grows slowly at 1° C.in bouillon. In milk the growth occurs mostly on the surface. It forms a yellow rim and pellicle and slowly solidi- fies it, but the whey separates very slowly. The fluid is viscid. Litmus milk is blued, and subsequently reduced (1 month). After boiling, the color returns red. It does not grow in Cohn’s solution. It grows readily in Uschinsky’s solution, making it viscid, like Bac- terium pruni. In this fluid rods with enormously thick-walled capsules occur. It makesa moderate growth on potato. It does not convert the fluid around the cylinder into a solid slime. There is a copious starch reaction with iodine even after many weeks’ growth. For experiments in fermentation tubes a basic solution was made of river water containing Witte’s peptone. In this the following carbon compounds were tested: dextrose, saccharose, lactose, mal- tose, mannit, and glycerin. The organism grew readily in the open end of all the tubes and clouded the closed end except when lactose and glycerin were offered to it. No gas was produced from these carbon compounds. It did not produce gas in any culture medium, except possibly sparingly in beef peptone gelatin. It should be tried for gas formation in presence of inosit. On thin sown agar plates the colonies may become 1 cm. in diameter. Often they are smaller. These colonies are circular, smooth or wrinkled. The colonies are similar on gelatin and finally form saucer-shaped lique- factions, or if the plate is thickly sown the whole becomes fluid. It grows well the whole length of agar stabs, and sometimes sends out small brush-like projections. Growth is much paler in cane sugar agar, but becomes yellow with age. Indol is produced in 2 per cent peptone water, but less abundantly than by Bacillus coli. It grows readily in bouillon over chloroform. It is not killed by drying (four- teen days). It stains well by Gram. It is yellow or becomes yellow on all ordinary culture media. SHRUBS, SHADE TREES, AND FOREST TREES. We have no means of determining the amount of injury done by crown gall to nut trees, shade trees, etc. The disease is common on the chestnut and the gray poplar in the eastern United States, and is said to occur frequently on the Persian walnut in California. 213 196 CROWN-GALL OF PLANTS. Under date of September 24, 1909, Mr. Frank N. Meyer, agri- cultural explorer for this Department, sent from Angers, France, a young plant of Arbutus unedo bearing root galls. From these galls bacterial colonies resembling the daisy organism were plated out and galls produced on sugar beet by pure-culture inoculations (Pl. XXIV, A). Lounsbury has reported it, or something closely resembling it, as prevalent and injurious on the willow in the Transvaal and Cape Colony, South Africa, where it appears to be a new trouble, having come to scientific attention first in 1899. He sent some of these willow galls to us and from one of them a colony was plated which produced slow-growing galls on the daisy and upon weeping willows (Pl: KXRY, fig. 1). HOTHOUSE PLANTS. Other than those already mentioned we have found what may be this disease on roots of lettuce (Pl. XXXVI, fig.2). Our attention was called to this by Mr. W. W. Gilbert, a Bureau colleague, who turned the material over to us with the statement that he could not find any nematodes in the root swellings. We also failed to find them. Thereupon poured plates were made. The plants shown on the plate were photographed natural size. They had been growing nearly three months and were badly dwarfed. There were many such plants in the hothouse and all had similar galls on their roots, and no other assignable cause for their stunted appearance, since the roots of those lettuce plants in the same house which had made a good growth were free from these nodules. The only other disease in the house was an occasional case of the drop. Agar-poured plates were made from one of these galls after prop- erly sterilizing the surface and colonies obtained which resembled those of Bacterium tumefaciens. With subcultures from half a dozen of these colonies inoculations have been made into the roots of young sugar beets, but no galls have appeared to date (13 days). BEST METHOD OF DEALING WITH THE DISEASE. Up to this time the best method of dealing with this disease remains the old one of strict inspection of nursery stock and the condemna- tion of all trees and shrubs found diseased. Im individual cases this undoubtedly works hardship to the nurseryman, but, on the other hand, to allow him to sell galled trees injures the fruit grower, serves to distribute the infection broadcast, and tends to destroy his own reputation. The nurseryman’s remedy lies in careful methods and the abandonment of infected soils. 213 BEST METHOD OF DEALING WITH THE DISEASE. 197 By no amount of special pleading can it be made to appear that an infectious disease should be tolerated on nursery trees offered for sale simply because it is rather prevalent and is inconvenient to deal with. Before the nurseryman can be allowed to sell such trees without restriction he must establish conclusively that it is not injurious, and not transmissible to susceptible species. We are disposed to include apple trees also in this recommenda- tion. While these seem to be less subject to crown-gall in a serious form than some other plants, frequently they do not make good trees, and our cross-inoculations suggest, at least, that they may serve to carry the disease to other plants and into localities previ- ously free from it. Moreover, even when the apple gall does not itself seriously injure the tree it may serve, as we have seen, for the entrance of other parasites. In some cases the inspector will be in doubt whether to con- demn stock or pass it, particularly when the trees have been care- lessly grafted and show more than the ordinary amount of callus. He may then either refer the specimens to some more experienced pathologist or refuse to take chances. Until we know to the con- trary excessive callus should be regarded as incipient gall. Ordi- narily there will be no difficulty in determining whether or not a given lot of trees has crown-gall or hairy-root, except when the nursery stock has been dishonestly pruned before shipment to remove signs of the disease, and then usually some traces will beleft. In case trees are improperly condemned there is always a remedy at law. SYNOPSIS OF CONCLUSIONS RESPECTING CROWN-GALL. (1) Crown-gall is a disease common in nurseries on the roots and shoots of various plants, and likely to continue on the plants when they are removed to orchards, vineyards, gardens, and hothouses. It also occurs on various field crops. This name is used for the disease whatever the situation of the galls on the plant. (2) When we began our studies the cause of crown-gall was unknown, and by them it has been determined. (3) Bacteria were seen in crown-galls of the daisy in 1904, and the studies then undertaken have been pursued continuously to date, and are here first offered in complete form. (4) The first successful isolations and infections were obtained in 1906, and the biology of the bacterial organism derived from the daisy has been determined more carefully than that from galls on other hosts. (5) Hundreds of pure-culture inoculations on daisy have removed the subject from the domain of speculation and shown that the galls 213 198 CROWN-GALL OF PLANTS. on Paris daisy are due to a white schizomycete named Bacterium tumefaciens (April, 1907). (6) This organism is a short rod multiplying by fission and motile by means of polar flagella. It can be grown in many sorts of culture media, but does not live very long upon agar. It forms small, round, white colonies in agar or gelatin poured plates. Under unfavorable conditions of growth it readily develops involution forms. (7) This schizomycete differs from many bacterial organisms in not producing open cavities in the plant. It appears to occupy the living cells in small quantities, causing rapid proliferation. (8) We have not been able to stain it in the tissues, at least not satisfactorily. (9) It is readily plated from young sound galls, i. e., those not fissured or decayed, often in practically pure culture, but it comes up slowly on +15 nutrient agar, and generally not very abundantly. It grows, however, promptly on agar when transferred from cultures. (10) It produces galls most readily in soft, rapidly growing tissues. Ordinarily, resting tissues can not be made to produce galls. Turnips seem to be an exception. (11) Cross-inoculations to plants of other families have shown the daisy organism to be capable of inducing tumors on many species in widely separate parts of the natural system (Compositae to Sali- caceae), these galls varying somewhat in appearance. (12) Some species of plants were not infected (onion, fig, olive) and possibly are not infectable, but further experiments should be made. (13) For purposes of comparison natural galls have also been studied on the following plants: Peach, apple, rose, quince, honey- suckle, Arbutus unedo, cotton, poplar, chestnut, alfalfa, grape, hop, beet, salsify, turnip, parsnip, lettuce, and willow. (14) From all of the preceding, by means of Petri-dish poured plates on agar, schizomycetes have been isolated closely resembling (as grown on agar) the Bacterium tumefaciens obtained from the Paris daisy. (15) With eight of these organisms tumors have been produced on sound specimens of the species from which obtained. With these eight and two others (not tested on the host) tumors have been produced on daisy and various other plants, thus tending to show a wide range of natural cross-inoculability. (16) On pages 133 and 137 the reader will find tables summarizing all the results of the inoculations. (17) These organisms have been studied comparatively as to their morphology and cultural characters and found to differ only slightly from each other, and from the organism isolated from the daisy, i.e., the agreements are more conspicuous than the differences. 213 SYNOPSIS OF CONCLUSIONS. 199 (18) The beginnings of the galls are visible in some cases as early as the fourth day after inoculation by needle prick, and they often reach a large size in one to two months, but frequently on woody plants they continue to grow for several years. On the contrary, sometimes they have been very slow to develop. (19) Some cross-inoculate less readily than others, but in general the monotonous morphology, the cultural uniformities, and the ready cross-inoculability (daisy, peach, hop, grape, poplar, alfalfa), point to one polymorphic species rather than to several distinct anEEeS, but further studies should be made. (20) The galls are often rapidly invaded by saprophytic bacteria, especially the softer galls. On agar poured plates many of these bacteria are readily distinguished from the parasite by differences in form and color, but others are distinguished therefrom with great difficulty, cultures on other media or inoculations being requisite. (21) The galls also invite various parasites—nematodes, fungous root rot, fire blight of apple and pear, etc., and some of these are able to cause great damage. (22) We have not been able to distinguish etiologically between hard galls and soft galls. Even the hardest crown-galls are due to bacteria which closely resemble those found in the softest. (23) Overfed plants are more subject to the disease than those making a moderate growth. (24) The size of the tumor, other things being equal, depends on how rapidly the plants are growing, i. e., the state of nutrition. Actively growing plants usually developed large tumors when inoculated, and slow-growing plants none at all or small ones; but, as In apple, small slow-growing galls may finally become large. This long-continued growth would not be possible if there were not a very nearly even balance between the stimulus of the parasite and the response of the host. (25) The apple hairy-root, hitherto a disease of unknown origin and supposed to be noninfectious, has been shown to be due to bacteria which culturally and morphologically differ, if at all, only slightly from the crown-gall organisms. (26) This causal organism is located not in the hairy roots them- selves but in the flattened tumor from which such roots arise. (27) Typical hairy-root has been produced on sound apple seedlings by pure-culture inoculations, and in the same way on sugar beet both galls and hairy-roots have been obtained. (28) These abnormal growths which we have designated indiffer- ently as tumors or galls are believed to be like malignant animal tumors in various particulars: Permanent and very rapid new growth containing all the tissues of the part attacked; enormous round- 213 200 CROWN-GALL OF PLANTS. celled or spindle-celled hyperplasia; great reduction of amount of conductive tissues; early necrosis, especially of the more fleshy tumors, with renewed growth at the margins; frequent recurrence after extirpation; extension of the disease to other parts by metas- tases, etc. (29) The disease is one which progresses slowly, stunting the plant first and finally destroying it, unless removed by extirpation or by the development of increased resistance on the part of the plant. (30) The continuation of rigid State inspection with rejection of diseased nursery stock is recommended. (31) The organism is moderately susceptible to germicides but can not be reached in the galls. Moreover, germicidal treatment, after excision of the galls (p. 184), can not be depended upon in all cases because of the tendency of the organism to form metastases. (32) The organism from the daisy loses virulence on culture media, and in some cases is believed to lose it also in the tumor itself (daisy, hop, sugar beet). (33) The organism is believed to occur inside the rapidly prolifer- ating cells, which by its presence are stimulated to divide with formation of the tumor. (34) During the progress of our studies a new disease of the sugar beet has been discovered. This disease, which is liable to be confused with crown-gall, causes overgrowths of a coarse nodular nature which soon disintegrate. It appears to be a more serious enemy to the sugar beet than crown-gall, and is one to be greatly feared should it become generally disseminated. We have called it tuberculosis of the beet, and have designated the yellow organism causing it ——— beticolum n. sp. (p. 194). 213 2 Leama ST. th im hoe ae Wl eie a ce | as cine’ ts ae PIAL. Ning a ig ny f-5," J 4 ql WARY iw pee + ‘te tats, a7 AT Am ee shi cc i (oa gia his ats ohn ane a ab Vata te Phd hence aed tht gan he me Ae, rth A nl awaivis eas ray raed eal td | hy n¢ , a" aod bel ani ee aoe) Te Pee wehbe : U ‘ 4j ay Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture PLATE |. (1) Daisy on daisy. Natural size. Inoculated Dec. 13, 1906. Time: 2 months 10 days. (2) Daisy on daisy. Three-fourths natural size. Inoculated Dec. 13, 1906. Time: 7 months. PLATE Il. Bul. 2-13, Bureau of Plant Industry, U. S. Dept. of Agriculture. (1) Peach on rose; inoculated Jan. 15, 1908. (2) Apple on apple. Galls at x, x. Tir (3) Hopon tomato; inoculated Nov, 21, 1908. eC - 9) + i} ime: 3 months. onths. 2:2 months 26 days, (4) Chestnut on sugar beet; inoculated Nov. 13, 1908. Time: 33 days. Gray by) potato; inoculated Mar. 27,1907. Time: 26 days. (6) Rose on sugar beet; inoculated Dec. 3, 1908. Time: 19 days. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE III. Top: At right (B and D): Daisy on oleander; inoculated Mar. 12, 1908. Time: 6 months 9 days. At left: Natural gall on oleander from California. Bottom: Hard gall of apple on daisy; inoculations of Nov. 9 and 18, 1908. Time: 8 months. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture PLATE IV. Eee ¥ ry j (1) Nematode gall on sugar beet, from Chino, Cal., 1909. (2) Daisy on red radish; inoculated Apr. 26, 1907. Time: 3 months. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture PLATE V. d Apr. 3, 1907 Time: 2 months 24 days (2) Daisy on gray poplar; inoculated June 9, 1908. Time: 6 months 15 days. (1) Daisy on grape; inocula Bul. 213, Bureau of Plant Industry, U. S. Dept. ot Agriculture PLATE VI. (1) Daisy on peach; about two-thirds natural size; inoculated Mar. 11, 1907. Time: 10 months 18 days. (2) Peach on sugar beet; inoculated Mar. 11, 1908. Time: 54 days. 7 ~ 7 : | e 7 Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE VII. (1) Daisy on carnation; inoculated Mar. 2, 1907. Time: 6 months 16 days. (2) Rose on daisy; inoculated Mar. 21, 1909. Time: 5 months 23 days. (3) Alfalfa on sugar beet; inoculated June 14, 1909. Time: 2 months 9 days. ry & v) uo Asivqg ‘paod Avi Wot} spuLi|d You ‘Sollos ouius vINd UOIPRINOOU! BANApNo ‘V9q jos ‘OW ) §6"6O6L ‘b "SUJUOLU p Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE VIII. sw PLATE |X. 13, Bureau of Plant Industry, U. S. Dept. of Agriculture 2 Bul. (1) Daisy on hop; inoculated Apr. 10, 1907. Time: 3 months 15 days. (2) Daisy on cut surface of raw turnip in covered Petri dish in laboratory, (3) Grape on almond; inoculated June 28, 1910. Time: 31 days, Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE X. (1) Grape on grape; inoculated Aug. 31, 1909. Time: 43 days. (2) Grape on daisy; inoculated Aug. 31, 1909. Time: 4 months 19 days. (3) Grape on daisy at the crown; from same series as fig. 2. Time: 7 mor ths 19 days. wor It Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture PLATE XI. (1) Peach on peach; inoculated Dec. 5, 1907. Time: 41 days. (2) Daisy on peach; inoculated Apr. 6, 1907. Time: 3 months 6 days. 5) (3) Peach on peach, second series; inoculated Jan. 13, 1908. Time: 50 days. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture, PLATE XII. (1) Hop on sugar beet; inoculated Apr. 17, 1908. Time: 31 days. (2) Soft gall of peach producing hard gall on apple. Three-fourths natural size. Time: 2 years. {Mold | 4 ‘Blf Ul UMOUS S| *sABp ZL SUJUOW G “| *SyJUOW pf saws] ay} JO GUO WJ} paze|d Sa!UOjoo YyIM ‘8O6L ‘€ ‘Ges pazeB|noou| (Z) :Asjep uo yovad ‘L061 ‘vy ‘09d paye|noouy (|) > Ou Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XIll. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XIV. Peach on geranium (Pelargonium). Slightly under natural size. Inoculated Oct. 13, 1908. Time: 3 months. ‘6061 ‘91 “Ady payejnooul !(UMO4D BAOCGE Wa}s UO BUO ‘UMOJD UO ||/B3 BUO) puowW |e Uo doy (Zz) Paul] *syyUOW LZ ‘8061 ‘22 (390 paj}ejnoou) !Asiep uo ajddy (1) Poul | *syyUuOWW Ql Bureau of Plant Inc dustry U. S. Dept. of Agriculture. PLATE XV. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XVI. (1) Chestnut on daisy; less than natural size; inoculated Nov. 13, 1908. Time: 4 months 10 days. (2) a, Alfalfa on alfalfa; inoculated Sept. 7, 1909. Time: 2 months 25 days. b, Ordinary nitrogen-fixing nodules of alfalfa, introduced for comparison. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XVII. \ beet: (1, 2) From one series o7 inoculatior the normal oculated Dec. 22,1908. Ti ilated Nov. 11, 1909. 3 months 19 days. (3) 7 * }O >,§ ‘ady jo Ssuolze|NooOU] S ‘6061 Paw *sABp g syuyUOW ‘seod} ajdde Sunod uo payejnoou! }oo.1-Auiey ejddy | 30}0Yd Yy}oOq L Ul SYJUOW |B41aAes Jaye paydes : JOyoo|e N 4 < =n o < }USI4 }e S}OOI Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. -PLATE XVIII. PLATE XIX. 13, Bureau of Plant Industry, U. S. Dept. of Agriculture. > Bul. > ea a “25s wat i ay ers FEE , ‘ tit Gis ee aN : Hairy-root of apple on sugar beet. Two sides of the same beet enlarged twice to show small galls with clusters of roots originating therefrom. Inoculated Nov. 11, 1909. Time:4 months 27 days. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XX. (1) Stizolobium pruriens S. P. I. No. 21300. A nematode infection occurring in the hot- house and supposed at first to be crown-gall; young gall on crown, old decaying gall on root at left. (2) Natural crown-gall infection of young rose, from a hothouse in New Jersey. ‘sjaeq 4edns uo doy ‘aZis |e4n}eu Sy ylj-dInoj ynogy ‘aunqjnogns YzX!S-AjUeM} WO} 'OL6L ‘Z ABI JO SUO!}B|NOOU] saw *SULUOW ZG Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XXlI. a” A," fe - » i Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agri culture, PLATE XXII. (A) Daisy on salsify. Pure-culture inoculations of Feb. 27, 1908, at the points where the galls developed. Time: 2 months 9 days. (B, C) Poplar on sugar beet. Pure-culture inoculations of June 4, 1910. Time: 31 days. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XXIII Crown-gall on white poplar from Newport, R. 1. Three-fourths natural size. Stem above the gall much dwarfed. Except that part here shown, the gall entirely surrounded the stem. PLATE XXIV. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. (A) Arbutus on sugar beet. Tumor partly decayed. (B) Grape on sugar beet. Inoculated May 7, 1910, (C) Flats poplar developing on immature grape stem. About three-fourths natural size. Inoculated Nov. 8, 1909. Time: 7 months. Slightly less than natural size. Tumor actively proliferat Inoculated June 4, 1910, Every one of the punctures gave a tumor. Time: 47 days. Time: 1 month 14 days, Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture PLATE XXV. from bouillor r +5 Q 4 } ALC oO 4 ) Hard gall fT The large colony is an intruder. as a. (f) Needle stroke of daisy organisn slant agar, photographed after so (g) Old tube of sterile milk. (h) Similar tube inoculated 2 months with daisy organism, showing the pellicle formed and slow separa- tion of whey from casein which remains undigested and fluid. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XXVI. (A) Photomicrograph of section through a very young daisy gall on rib of daisy leaf. The most of the cells of the leaf rib are not yet involved in the abnormal growth. (B) Photomicrograph of section of small daisy gall, showing supporting stroma and abnormal conductive tissue at y. A small portion of the nearly normal tissue is shown at x. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XXVII. Photomicrograph of section through a rapidly proliferating gall on tobacco. The centers of most active proliferation may be seen crowding the older parenchyma cells out of place. Here and there (x, x, x) may be seen small groups of abnormal vascular bundles. Margin attop. Toward the left at top is nearly unchanged parenchyma. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture PLATE XXVIII. es: aX "= » c ¢ z le Ver x Sant AY oy rr ate eG, ePoas FARES, o225 Faces > ea ~ _ - cys Seen LEIS = BS BD / eA i ee Oty, a > Ss ‘ese vay Si) CL ba. ‘ aNce> a « wre — } >, Px n>) Nee ae WO pSRep Cross section of a daisy stem 10 days after inoculation with Bacterium tumefaciens: N, Normal epidermis and cortical parenchyma. V, Vascular bundles nearly unchanged. T, T, T, Rapidly proliferating tumor tissue at a distance of 1 or 2 mm. from the needle puncture. The tissue is pushed up over this hyperplasia from a to b, indicating location of the future gall. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XXIX. Ce vers So >. * as Cross section of outer part of a tobacco stem. The lower half of the plate shows normal cortical parenchyma; the upper (outer) half, rapidly proliferating small-celled tumor tissue resulting from an inoculation. In the upper right-hand corner (in cross section) is a recently developed vascular bundle. ae Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XXX. Radial section through a daisy petiole showing the internal origin of a small metastatic tumor. The normal tissues are bracketed, the epidermis is not yet ruptured, and the tumor includes all kinds of tissues peculiar to the petiole. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XXXII. (A) Limb of Spitzenberg apple from Oregon attacked by a hard gall. Introduced to show a secondary infection by the pear-blight organism (B. amylovorus) radiating from the gall. x, y, Blighting areas covered by the bacterial exudate. (B) Destructive galls on blackberry received from Prof. L. R. Jones, Madison, Wis. Autumn of 1910. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XXXII. fail eg a y) Photomicrograph of cross section of a daisy stem including a portion of a gall. Introduced to show centers of rapid proliferation. Atthe rightisa portion of the normal stem—wood, bark, epidermis. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture PLATE XXXIII. Crown-galls on Brassica due to inoculation: (B) Cabbage. (C) Collard. (A) Enlarged view of C, showing clusters of roots (hairy-root) growing out of the lower half of the gall; year, 1910; time from needle pricks to photograph: 3 months. (D) Hairy-root of apple on quince. Time: 19 months. a - =. Verw= P 6 LP Tw pane ef J — “a 7 ——o ! * 7 . 2° 7 ? | as Yr A 8 ae “ : - ‘ ™ o = ‘ 7 nr 7 ‘ ‘ : e e : al 0 . ~ le y bd - zs i. . Sy - ? L PI Zi » ¢ . > é ‘ - ‘ ‘ , ; - - oe ‘ y ‘ 7 ° ) ran | > a . ‘ * - 2 ‘ = a. = cd : ore 7 PLATE XXXIV. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. (1) Sugar beet from Colorado, showing bacterial tubercles distinct from crown-galls, attacked by fungi, at x, x. (2) Sections of some of the upper nodules showing the central brownish water-soaked bz reas Surrounded by white flesh. dules much maer 1ified, to show the small central rifts in the of one of the no ed to in the text. Bul. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XXXV. (1) Gall on Salix babylonica induced by needle prick introducing pure subculture of Bac- terium tumefaciens plated from a South African willow gall. Enlarged. (2) Galled quince stem from Dr. Trabut in Algeria for comparison with Plate XXXII, fig. D. PLATE XXXVI. ry, U. S. Dept. of Agriculture. + Bul. 213, Bureau of Plant Indus (1) Beet on beet; inoculations of December, 1910. Time: 44 and 52 days. (2) Hothouse lettuce, Maryland, January, 1911. Badly dwarfed. PN DEX. Hane acia involution forms'due to. .-2-52..-.. 22.225: elaee ees 168 PIoMUeEMOnNGr -s2-- es aerate het le eee 125, 174 PPCTAUOTN OLS Aimee has iich Sak ARE DSS SEES Lee 112, 117, 119, 148 PME MIDTOLUS WOTOWLO Ie: 722 52 S22 sed.) ler eeeetesc hl es thas 112, 117, 119, 143 Merdtnituss. 2 o22....- RR ET NS a1, ME ceeea nk Soils 108, 127, 128, 129, 130, 131, 132 EeraeIOnIOl CUlLUTCS. 2. fas 2. Sok oye ots fle Sh eA 142, 154 PERC ORninCal -PTOWL OU. 28 D2. 4 ee 5 fos) ee ao Sos ee aaa 109 Bearealigient, plates, erowth On. .!.2....05...2 2252-6 eden nce 5h soe aS 62, 63, 97, 108 SlLabswerowihtines ssa a5 wae tT RRS YTS el es hee 109 Birenike OrOWAH OMS o2 : 22-5002 oe See ince 26 Bes tense 74, 109, 140 PeenMe ou, PrOduUctiON Ol.22s- 2222222222 2.2 2k ao. 6222 2 ol shed eS: 125, 174 PEs GeCurrenee of crown-gall ON 2: .4.s2c2e2 beaks en sihe bs ei eee oe - - 191 Alfalfa organism: Pu TCREAN UM ns ee as a2) Ft eens | SRA a aS SPR See 129 MemlinmeteHATACtens so /)2. 5.28 2.) oe rh Bion eet lasbye 140 Je IS 2 ee eee cia SC) eee ite eee Ene ee a 129 (CED ESRD GS ne Or een Serge Seem eee ee Cte cigs hee a Sto tere es eae epee a 129 MRRP RET LOUSS ots os tt aS AS oS hoa SS Re a Pe epg Se 58 Sem PEL RI EOTIREETRS! Crs ee een ct te Ny Se ae ORY fl See del a 129 IMERHUTGINGH (Sas Uses tarsi netoete x yt Nea ot ape SY Aa AL ot ta ee 129 STt LEE Seg ake ea EE Se ey eR 129 PMU ecMinE Olena gl Ony Ole ase see esses =) St) ee eee a eee one 112, 117, 119, 143 AUeaMe Deer probs ero whl InN!.2 0.5 5 vs. se ees oie ee - - 112, 117, 119, 143 HOACUIO IO MCU GUINEAS yet nS 8 yeh thy hcl: Rel vlcp ae or Ake Ee ee te 142, 154 Mima aniury aie to crownl-Call 2 << .\../- 26 5.955 none mays e heath - waeelS- aie 183 Almond gall, ascribed to Dendrophagus globosus...........-----------+------ 19 HALCCLAGMS HT ALLIEG!O bokeh ms oan Se eS 3 hs Cele pe oho c ie wm Reh re 19 MOUIMe A ShW ORK) OI te ties tees ane eee remem Se ee te 19 Misbere; Ghemical analysis of flask cultures: . 5.2... 2022-22. -'.,-\- = 2-2 2j002 +2 === 174 PPMIRMPSERIE PIEOUICLION OFS ooo ace oie se ae a a ae oo am os Kn apne nn 116, 125 Ammonium magnesium phosphate, production 0.............-..--------- 93% | eb Ami cumors, likeness of crown-gall to...-.---.22--24---------- se 2sen a= - 45 161 Dee Many, ie! tO CrOWD Pall. 2. oun. tee se ee + so in ne pis te amereis ¢ 185 pa bard relation:of, to:soit, gall 225. 222s gees mics 22s se a ea feo ls 95 Andysort; dso lations irom snese semen co. 05 2 a crane eee 95, 96 Apple gall organism: J SETUPS pacth chat: | ee aoe CARs sea eh 78 eo ak Sas. kt A Ak are ee A 129 eine lecharacters tc = . oe ee ee OE EEE: == eo creie ore Gx eet 97, 140 TE GNA oe kee ef a Ae Ae cig So aids oc ee a tt A 129 TLL PS) eA Be ot ie ee Te 129 UTD E 2 Tey 5 COTES, Sethe als ag a eA AN oe SNL ae ei Ne 95 IMGaSITEIN EM Gsean sets pea eyes ere Oe ere eS eee ora 129 SUS SN Oe = Peed a bet eae) ae fein ie) i aS eA a a ee 129 Pppee tiny FOOL. IOlMbIONNIrOM 22. <- y)-- e oas e s eo eeee ee cage 100 IGGAtiOM Gn OTOABIRED Io 2 seins dessa «a's See daze eee 101 213 203 204 CROWN-GALL OF PLANTS. Apple hairy-root organism: Page. GIG, SOS tienen ences oho n weld cd nels dome SAE ae ee bee eae a 129 Culttral charscters< 22... ots shen. oe ee cece ke wed Oo ee 140 IAROUA eee neste rol be ee be heh ote edits eee wee ee pas ee eee 129 JS) iL 1 eae a Se cee RE ince en e'e Retaw ep ae eee 129 THGCHIBORS 5 osc ce nc coe 2h niks Se wns oe mete Sap Rhee eae ee 101 McanUTORIeN Tie 5 oo o.o oo bem is 2 oid epee prep dyes hm are a> cs ce 129 Belation te crown-gally so. ¢ ous eeoh os ooo ese Zetec ee eee oe 100, 157 DS POLCR ses soos cues ee Oe ee oc erate syeew aie eC lee eee 129 Arbutus unedo, occurrence of crown-gall on........22....0--++--25-.-5-555ee 196 Arbutus unedo organism: 1 SG Oe Oe ee Ore GREE Ei 130 Gulfaral characters 2. . 2o0s25ss552s0rredieacc dss db en gees ee hoe 140 APO a te hl dos ord gore ns tac bsn bee used OS ee ee 130 (Grant's Sioa ese Sess See es foie dec taee dade ote se ee 130 Inoculations with .235 52. 52222222-.<223- wave tees a 53 Isolation. Gf 05uoctenwece Bee 2 oo re dee SO ee 196 Moasuremonte: 2:30. (cei o-oo lea belt wees ea Be tee oe 130 PPOTEBe ino ogee sis anes doollee tal ges oo s Dee een 130 Asparapin in river water, growth 1: - 22.0... 2262.20.25 ).-.2422-- 2 =e eee 153 Bacillus ampelopsorse.- 22/227. ... 0-2 -2-v Je 22252222 1 2 14,15 amylovorus admitted through crown-gall............-..-----.------ 176, 186 POPC oso see oss Hoe het oedema s ot weed ee er 18 Bacteria in galls, location Of. =: -. 222220226 tee oa eee 23, 101 miutltipbication of. ..22222 22272222 se 45S a eee 167 probable condition of... 2 222-2-2-.- 4.2222. 22o= ee 167 quantitative test foros). 2.22.-2252.4-.-2.-5-2+s oe 81, 193 small number’ of... 2222200202252 -2. Se 168 ‘Bacteria in tissues; discovery of. ....:-222.02... 2. - oe es 2-2 oe 22 locatiow:of ~. .2 (222 2228 i. SS eee 164 siainme difficulty of): :2.2. 4022-2. eee 167, 170 ‘Bacterium beticolum; cultural characters’ of) s-.2-:22.22-.2 5... eee 194 description of22..02 22222 77.2.5- =... eee 194 Bacterium tumefaciens from daisy, description of.................--------- 105, 128 See also Daisy, Bacterium tumefaciens from. Barden, on crown-gall of apple trees.-. .-. 22-2. ------ 2s as se eee 187 Beek broths: acid) growth wa...) oe ee ee 112, 117, 119, 143 sikahine.ordwih in. . "Utne en ee 112, 117, 119, 143 nutrient, erowth im... 232.6. ee senes 3 a 111, 141 Beet, occurrezce of ‘crown-gall on. :.. 2.) 5. U Soon a ne os ee 191 tuberculosis vfs: 3 fi52 5. 2h Sen. Sane - aaeeea ys oe 194 Beet gall, ascribed’ to nematodes. -.-. 222... 52-0. oe oe 18 attributed to mites. .....2.. 80.2.) ot enn ee 18 chemical analysis of... 22222220... eon oes eee te gr 173 isolation fromse.t c..\. soo. oe oka ce Ooo oee See See 81, 194 yiames applied™o. .....-...- 2.20222 2.222202. 2558n sss eer , ae quantitative test’ for bacteria im-...-.--.------<=--+.-ss eee seen 81 Beet organism: Weldafdst sotto So ies oooh oo cote aie erence pinion Cees es er 131 Cultural charasetemim.. 2202... 5.25. 2c - ce k eee ese 6a ee 140 lagelta oo Sete ands Scis since ace selene Memes eae emia poets rn 131 Grams stainee os. feees <2 250. L deus ceweeetheckaah hoes ee Sec. 131 TMOCWIAGIONB Sc: < saiette was och nso e 2 wise wer oie wim emcee ce 80 213 INDEX. 205 Beet organism—Continued. Page. MEASULCINON Heese esos SON Sea eel 7s oho poe g AUS oat. LE FE EA te vat 0) D2 eee Oren erate erie Pierre: sor Pint nas ae ae 131 Pee cuemy, rnjory due.to crown-gallisj. 002225255222. P PU Te 188 EersentimMe seers yates 5 We eals seis selena oe eas Se ee eR 111 Besrewolk.on poplar tumor byi....2. 0/2 3b Sees ede ORO 18 Peeeenor on beet tumor by... 55.-..2.2Ue SEAS ee oe. 18 Butz, apple trees, injury due to crown-gall......--,...2--------2---2200222.. 185, nursery trees, injury due to crown-gall...........:..55225-222222002--5- 185 Cameer, probable parasitic nature of. .2...2 2.25 .20.22. 9.4.8.0. Mao... 169 Eesembiances to cCrown-pall )s 205522 ee Pee PRESS Bide 162 Cane sugar, in peptone water, growth in.2..22.2-....2. 0) 222202. ..2 22. 115, 141 BUIVEISION Ol: 525002 %e52264 s245222855254a75 see LI. 152 MEMES els toe 357 52 05532 [aad sh) ss2s4ise ess aaerares syed BELT 107 Gsyer, deseription ‘of peach tumor: .. 2... .2s20s55255155520 292.2222 16 MOPRW OL PUMILPOF CUMOT so). ac see Ne tioe Sek TY SO AZ MOEMPORS KORN. ).2 Sue Gano eeee ls Hees MRE O MS el haloes. 13,15 Chenical'analysis.of crown-gall of beet...2.02 25282. 502s. ili) .e eee cece eens 173 MOBkMC UL IEES I Sis sas sae n se ss SSI eA 174 Chestnut organism: CEST 1 St he Ss a ee a ae EA ee ae ea 130 EMP SINGMATAC LOLS Sci cr OR eta Ree Re ee Sel ae obec ee bar 140 eae ee Reis 59905 5k ASIC RR racemose te ge oe ob alee Ts esl aU. EOE 130 SEES SET pe peer ee peers oe 2 | Oe ce 130 Rema OSH atta os sas ss 2 54s RR ee es ae cee 90 a aE EMTS ESRI Og tons £1 TAPAS AL EEO RRS eB) Sse oko eel see ee 130 Rem N Lyre | 5 Sates ss te ee eee ee ae seins se net Seas ee asec 130 “LLG SS, © AG SO eg 2) ee re cena ee a scene lad Gilonnern,crowth in bouillon. over... +22. 205... 2... 22.2 eet se cane seb ees 114, 152 inter ee OVCL ARON OL. 050k 42 SCP I oe. oe nes cess 117, 143, 144 Ciena -ersicrs fuberculosis. 292 229229025. 23h. oss cae eee ae neh ee lees 17 Gisrersuceunrence, of crown-eall.on's).. G20 2 oe 4. oe ns be eae See eee eee 191 Gitbreot. resemblance, to.crown-gall..v: 2 222 ses oe eee bP ede 2 Te 159 eee aE ION, VOEOW LIN See SS 8 Sh S52 stot dies vers SREY 26 LOE 113, 145 Calg acolition forms produced ‘by... .2< 1..ssdesa0k oe ew LE Oo 168 Sian eAR IUUEEIOIG OA ae oo a(n 2 ee oe oS 62, 63, 97, 108 NN yh a oes eee soe cee SRY Om SEE 101 Capperisulphate, effect of, on orgamism......029.% 923945. 02.2 2.2.2.2 kt 125 SCE IV OUR ORE Hy FOX Cra De aro. o a p—. 2205 2a, ce paver > rw ee SEES ee to 13 Uanetoccutrence. of crown-gallion. . 22! .cb eee eee FL eRe ea 191 Cotton organism: 2 LEU ee 8 RE ee Cc aS 2 ap a ee 130 Sepetmrne Hartacterd: \)/0es eee 2h 4 ee ees det) ty re Ae 140 NN ee rs Sh tet a ae ee le a RIN yah cok = Savanna = SPRUE 130 SS TS a) eR ge ee at oe eS eA 2 OE EL 130 Remar ORE 9 aay Riles 8 8 a A 2 Les ie Be eee 54 niger itm EOP MIG Sop Eee es 251 Re 130 PRC BHEGHICH GA: oe 2 5 8. Pate ee eee ee OMe, 2 ee 130 AOL DUET gS ee See Tee oa wea a Se =, re 130 Cross-inoculable gall-forming organisms.........- Re hess 3s Lio Sees) PISS 156 Oy USSSTIN TS TESTS eae ae enn ene” (ae ee) Ae rn Se PSOE 156 Crimpa eal wamatoniy: Of 2 232os 4-5 she oe aye - eso wide. 159 CIBER DUTLOM OM. ie.5, ose se Ey oe yh tb aii 13, 19, 20, 183 2138 206 CROWN-GALL OF PLANTS. Page Crown-gall, effect of, on host plant. . .... 20 dno e ncncwinnasncnss oc weheeen 176 SRO WANN Olen acim nn ein, 2 am > ainday sala nom 8 eae cee ac ea 159 WISHOLY Of WORK ON. 622-2242 - bon sind Heb EW ERs tke Dee eee 13 INIURY CAUBOE DY = 2a 62 Bee 140 Guiture modis, vitality On 2 oo... 2 x LUGS OS AS a Oe era R ESS yr! Se ene 130 Grape tumor ascribed to Fusicoccum viticolum....................2-22.22+--- 19 Marsarodes -vitvume: 4-2 a ee SEs Wee SR yeh ani 19 BNIB POLITIES x7 emt hee eee Se SCs OTs 2 de ea Wf ; CONT ET ATS 00040) 0 ee a ere en EN De eye EU ena By Als Comvolsewoule ome oe) ee a ee RI 13 Gubonijs. work sone: 225. Asueeeas eee ak ee 13, 14 HAMeS APP NOG LO? = 19 peach tumor, first proof of... {0c acs.2s.c2-2 ste 19 raspberry tumor ..; - 4322p. seule es. 4-sk oe 188 Tnjury due to.crown-gall... 2. ..... .... <1 23m -c eae as 3 176, 183 Inoculation, reaction to, time required. § s...- 222 -2eece >=se- el bas 159 imoculations wo: S82 tt 8s! . 2-2 - ck ei poe ie Bee coe ge Ie 23, 24, 25 Alfalia on altaya 222.22 ceo.- - - DAaios ocean «Sea 58 GaISY. 322.2 cos eet - - soe oe ee eae s Sac se os eee 58 peach...222 2! si... -- Le weSee Se eR 59 sugar beet. 2.2... - . . paebate te seca ee ania 9 60 Apple pall, hard; on apple - . -. . 2.2225 -4ase=4 -Se dee: 3. - eee 98 aisys. . . .22e8eie os lE ten lee oe 96 Monstera. . 22.25. Jeceesees at acc 22 Re ee 100 Pelargonium 252: S225 121i... 2222 ee 98 supar beet. 224 ssec2 + see stt2 t5 2 see 99 tomato... - . -.2-djstiess Hae seen |b Jee 97 Apple:hairy root, on apple. .. -.--. - 425-2. sseas2eeee 2 - ee 103 daisy. ... = 22.22; ok oes CE eee ee 101 QUINCE. . 22-2 eee h ieee. ao- Geb a e 103 pugar beet... ..-2-----.-ccust See See 103 LOMATO. = so) fan et. c eet eeSe eee 102 Arbutusiom daisy... 222---. 22/25. 22-cecse 22 ee eee 53 sugar beetere 25.2062 Sees sos 2 ee ee 54 Beet onvalmond 7 262202... sie. Sees bho to eee 80 beet! 23 Jieises.- .. cutee seas pee ee 81 daisy Pca 26. es ee a oo 80 Chestnut'on daisy... 22. .---222)- 2558 Beteeeee ee ee ee 90 GTAPO ae. oc) - + a een ce pees ee Bee ee ee ee 91 sugar beet........- oseehebe ste: ce, CRE ee 91 Cotton'on cotton. . 221.8 2222-21 225-52. 0.- 22 See er 54 daisy. 25 22h -se Vs ates ase eae See ee 54 sugar beet. .@% .. 5-0... Lssves.. Se-e eee 55 Daisy onialfalia. 2 2/28. ii). <1. abet ele tee aa ee So 37 AMONG: thec6 «cnc. s os 32 lcs oo See eee ee eee 40, 44 BPPlOtins cusele = ove sks v's pe ss SHER eRe seb eee 42 APMCOL Ss etishs av tgeitoxiewcth se ceases ear ae eee ee ee 44 213 INDEX. 209 Inoculations—Continued. Page 2 EIT OTC ree he IR ee Tne Ape Pires A SRR Ne ee mf TPA 34, 45 PERCE DOREY oreo en ees oie. ee ee Hee ee 42 “| ) 12 {AR Se tot Oe ee Ea ae ae CIEE Weg) a 44 OUTST LR ICT aie ee 2 Sal Se aR ye PE ee ERE CTLs, Ae 45 SENS eta me ee EE kin an BO Ee ae 34 OE ons ho Re oe ee ee S| 44 SIEM bye ao ess a8 ee eS a A ae tly iy egy 44, 50 Chrysanthemum: coronariiimi 2 2 2. 2 Seed ephoh 2 28 CLE Si ei SNS, ELSE BE os sek ane eee ee REN Fe RI Pe 37 CCIDLIVIESC TST) GTR, Se Ae eget eae one a Reena, OF Regs 28 SETI ET Se a eS Ee she aR en 8. SN 52 daisy (Chrysanthemum frutescens).....................-.--.-. 25 DELTAS ENE SR Se ee ee Eee ne opener SY aa 29 ELT RSS RR a scene ee eT ee rm, 28 iL SS Re ee aN a a cs

Ue a ot ee a 43 HE ES AER eee renee ens See AEE ee eee eae 34 SELES eS ge ice een nS eee ee es a ee 29 Shasta daisy. (Burbank hybrid): 22 5.28. :. 2... .. < skledeenonc se 28 CLR See Sac a ao . Ca: - o n 30 ELL RE Ae Oe i eee = i ee eres 30 ES ae eee aac Re eee |. eee” ean ee 34 <2 i522 Oe A See Sean eee eae oer 50 ELLIE E CoS C7 A a eee ear Res hs een cS 56 ETE Gales See epee SoC Cc tS ane 55 (Ue Oboe ate OER Re POE OS ea ae Ess Se ey eee ee 56 IS eS Se ee. aS: : Sa ee ee ee 56 RUSS aes Ae ee) ly Se ae 57 eee PoHCRAG OM AIRY S 5 ee ee a 2 a 53 Ie anit 2 ae an ay * © ie a ee 89 EUG Pea oe ieee ee ee SE Oe ee ee ee 88 ET CS i ae Ee a ee ere ae 85 78026°—Bull. 213—11——_14 210 CROWN-GALL OF PLANTS. Inoculations—Continued. Page. OD ONDER DG. ooo moeen- coat ner ewe ws eke e cheek oxen Wainer 88 DOO soe sk be ce rd chade tse chhvcduat awe de ku se sw ieee 90 OUT osetia td Wan RSE e Sku eke pen wel i tenia Onn 88 POODIB.. eden er csee coy chases tek cp hone Soe waes eee ne 89 RUREE Debbess oo... Cenk hee reek cote eeeeeeeee sce nee cee 89 i a ee a ee kere re re 87 Parent OH PALEMIp.....-faaverei esa enon eee shots kerk eee Dee 105 spar beet. soo... ee 2 roe POU eee 105 Peach on apple. 225s i2e eee et pane tA REAR OR LS hte 68 beet... cca coin cee ee ee ee eee en Lee en oe 73 MOIBY. socce lk cwa eds a eet ete eee tek tk er 60 BTA or. erste eecire et Sas See De ne ak eta eS Re ae Oe eee ea 65 (c(o) ee ee ees ree ee Ik 73 Tmpaienss-ih0 on eee eet LE eee 65 Mopnolia:.: 225-062. cee ee ee 72 Oa se Sea ea et es ee eC RRL a em el 73 GUVO 2st 4 222 acct.’ oa. Salas eae see eh oe ee ee ee on 64 peach eee Ses a ek RR ks Oe ee er 66 | IPelatpimIMOT: 22. sc ok ws Sioa a es 66 | POGUE at fois. ~ + 2 ee ee se ea ek one eee 73 | PhiOR ee see secre: .. eee tahoe eee eee ee 65 | TAAP DOREY A Ve oe Oe, 71 | TOGO SC Sos oe ele te > = = see ee eee eee ee tan er 72 | Tradeseadidas <2 55... = -o2oo5. dae far oe oes Pe 74 | Verbena 2:21.28... 0. tee es eo 65 Wittens eee 3 OL ERS ee 74 Poplar -on Apples--- sees... 2 a Se se ets ee 93 DPASsGAS = genes <2 ose eS ee eS Se 93 Callas so. cpetedie-.. - o bee eG ese ees ee es 2 94 | cotton..... 92 PTAPE fe) .e. See. a ss ES ers Pet ee ee er 92 oleander:-u. css. --. 2. ee ee eee 91 Opuntia. 222229... ee Waele SSC Sus ie hee 92 sugar beete: 320... ye ee ee ot ee 93 Quince on-daisy*esses2 S.-i PrP tee) Selby 78 QUINCe... 222 32. le ee ee 79 Sugar beets. fo tr ee 2 80 Raspberry on daisy: 22252... 02. 0... fas a 78 Roséon apple: + 228s. 0. 51 EE a 77 Peet. 222A teseii ee ol. weer i ee eee 77 Oaisy = 223322. 2 oo A eee 75 Peach . oi sae 2. oe os Se De ee 76 TOBG S22) WSS 2 ot AE te ee 75 Salsifyonssalstfy 0 .<2ts2.. 01 r0/ foo ode 105 suger Heet.c BE. ..-..sst escorts oe oo 105 Tumip On sugar beets... << soi {gree ede ee ee 105 CUPOND: 25 PE os oes SS ae eee San eee ee ee 105 Willow on daisy: = s22::te- 22022 foto tote oe 94 Willows: sesto- ess sse cored teed 27st eee oe 94 Tnoculations, immunity tests on ‘daisy. -522222.222. 15232 fe 177 tabulated results of, negative or doubtful...............-.-.---- 137 Positives ses... 252 aL Se ee ee nee ieee 133 213 INDEX. Dil. Page Peper anvol slitsery, AtOCK (<2 203 3 he me laa ool Sees, aS ee pee oe 196 Rimes SPBNETFOUUCHON. OF 5 aco. ook eae af na ina 302 = =. oe eaioier Lerek 125 Reere ETON MORINSS ys, A ohare ie alae oe eee ok St ess 107, 128, 129, 130, 131, 168 Feerinion iromiapple gall (hard and soft)... 5.2. 2222-2... 3. . 2 oR + + «+5 -ahtee | 90, 96 any -LOOG oo 2a ae seta ae inc oe Se ee 100, 105 Olatsy =o fees. Moe ae oe abe ieee ee Oc. = ae oe eer 22, 24 DRAGS s oon eee ele. MRE Seen tes ae Said 2 eee ate 61 BIE D ORB eee ae atta ic eee Se 28 Soa elie. or ens rena 81,194 PERRET ey an ras ee I oe hs of Sie ok AE 168 Joence workaon erown-rall of beet... - 22.8 os\ci< 25...) 5.0 2 ons sb tee) EE 166 deempeweatl Oxvare Ss Gescription Of: 2... 52-2. sas ea eeeaeses-ap +. ~~ <2! 17 Bibra tamor ci Ort LOSE CANKER 6 2 5 se oie cn la ain 2 al eh bn ae neyas este sis), Seer - 18 Peete i PEOONCHION. Ol. 320 F..2 <2) ahaa slat ws ears adenine owed Se tees 125 Mame pepione water, Growth iM... .- 224m sei hese bleh be SHieeereeigs}- + -- - = 115 BeeeioewOrk OW STApS tUMOE. 2.2. 2-<25- 225-2222 2 ois cee ok ose meieek 2 - 19 Me npa WOE OW TOSe CANKEM | 2-2 is atte be Na eis ooo AER oe 18 Lettuce, occurrence of a gall on.........-. SOP Be SSS 2 oh © i le 196 IME PRR EC LI OIE OL p92 oo) coc hls em ee aeatin Se cae ann ed os Sees 113, 154 eer Olood SETUTM, CrOWtM ON... .2--- 2 -<2-5- 0-02 2-3 os ees esses --Saee 111 Lawrence, blackberry, injury due to crown-gall..............-..-.-2----.---- 189 ame ITE VATIOUS MCUIR sooo oe ola ote oe Se = a(S a5 a eda ss A SES 115 UT EEES CIDE ee Se a ee DS RE es cee 183 Peamonury willow callsin South Africa.:...22..: 25.4.0... +-+42- 54-5 8ess 196 Malic acid, leaner Oi Solus otal oe Etsecti4 fener y WN NAS AA Malignant animal tumors, Peeeeblance toe crown meal Sea ia ec ayS gs Bel Ase. | yeh Ae aS 162 Maliosean peptone water, crowth 1M... ..- 2... 2.22. $e) Ayes gaen- 2-2 115, 142 Manmiban pepione water, erowth im-...2..-..22 22-252. 5ide. smesteek-s--555- 115 PERMITE TINOCEAUIEOS..-'5 00552 soho Fc 5b 35 cis A aes eee so 225 Se 121 Measurements of crown-gall organisms. . eee er lO MOT 2a N29) TOSI Sieg? Mechanical injury, attempt to produce g esis — eu itas _ apae psa hgyey so ee 23 METeRm CUIOTIO?, CHOC Ols, <.42=2 925525422 22 cele. tosh tS Siete - sos ee 126 NIGIRGUS CETL S235 Ge Seen Ocoee ae eee ee eee Ske S SE os Eee ee Spee 163, 171 NE Oract DAGLETIO IM HSUEH... 2.22... <= o-so2 eee = 25 gers Shoe oo eek eae 164 WitiewerOmaliviie cn: oo Sse 8 a ows eng See 5 =, So Ee ees 112, 154 IDPRIEMTEDMET OUND DEA HEC ose cs 3 as ais as ho A ae od mays ns EE 122 Morphological characters of crown-gall organism .............-2.-+-.---+----- 105, 127 Bement CAUSCA OL 2. hos. ais = 2 oc See Ee oe Ss ow g eh win ee 161, 175 Beet CUO hh OMe. tas tS as in ee no a oc IN 116, 148 SOE eee THUG UG LOM are, semi a SS oo ne Eh Oe oe wg 3 5 oie 114 meleietiore than, one immecih. 22 = ok. . oc 3 ate eee boss aee os SUL 160 Ripper mE EAC es SD CCL ON) Gi «onc oo ee 196 Nursery trees, injury caused by crown-gall..........-....-..-22.......2+--- 184, 185 O’Gara, apple trees, injury due to crown-gall....................-..------.-- 186 Oiditienies, lesser susceptibility of-. ... <2... -< 2 28 Bag Bs A 158 BenitmprImiOMPCRaLUTG.—— 22s. ooo. 2 as ee ee ae ees. 2482 2 = eS 120 SEITE 10 ee Se eee Es oe a ee CeO OL 118 Organisms, crown-gall, from various sources: BP Nga eC TISLT ACO TS sc Bg i ee eo ia a 140 LLL SiS TG 1 Se eee RR en R= fine te 3 Se Se a Aloe 127 Geremisms..fall-forming: Taces Ol! .> 6-6 oe ees sco wd ono eo oe Re 156 Gxidizine enzymes in gall tissue, excess of...-:.-----/----------.<08 0 dentegee 173 Peep Ctl ABOIION MOMs 3-2 ose <2 eee et isc esl 2 sis Scns xo SS 105 213 219 CROWN-GALL OF PLANTS. Parsnip organism: Page. PT ft ae ee lS oh RE RP erg ek 132 Culturalicharmeters-<0 2-8 seek UL OR See: Rtg Ses eee 140, 141 PUAMON sen sees ee SEP LCE AT clas pu Deh mut eee he et is ee 132 PDP OU a aes Che as la Se DEUS OR Ee Ente ce ot ee ee 132 PEM SRI eet ce bth St Lets bt See oe ee 132 PNOSMIRGOMS= ae estos Ue ky oe es ee eee hen kee ees Se 105 Measurements: = 22 be ket cet ti cab heed. ost 132 EMLPOPRINCIUY s foton os coco ce back ela wsiv 2 2 Oe ws eee oe oe ee 132 300) «2 Ee Aa Se a a ee a A yt 2 132 PALMOCEHICILY RUB OL ereeL Ee Lee 2 kts 22) tot eee eae 126, 140, 157, 165, 177 to many families. ......25:522222.05.0 0. 002-22 2 <2 52-2 oe Peach, injury due to: crown gall. -:>:--.-.. 22.20. Lk See 184 gall, Cavata’s deseription of .....- 25.0.2 222820 ee 16 first proof of infectious nature... 2-20 2022. I, oe 19 ASOlMULOR MOMs 2285.00.24 CoS LSA ee 61 Peach organism: ACid-taBt: eo oec ces Set UCAS bs SLA ee eet eee 128 Cultural eharmetem So To. 2... ELL eee 62, 63, 74, 140 Plagella Jf -< settee tte. 2 jt rs se ee 128 Gittins simak, Ce ee ee te) 2 RRS, BN Ge 128 Ineeulations:.< ss /2Ace eects + tee chtgss Lt 60 Moensuremente ss 22052265 .2.. 22s ete tee on eee 128 SPOS se5.c2 2s esseeec ek eee te Le ee 128 Pear blight, crown-gall followedby --.-....2...0/ 22h 22 t> ee “186 Feptone water, prowthan-: +... 2. 222021. 22 147 Cane Spar Wibhe.: .. $0220 228i toes. ss cee eee 115, 141 dextrose with... 2... tie 2<) 0 SOT Se 112, 115 Glycerinvwith: =)... 042.0005. 22520 12 Cee eee 115, 153 lactose With-..5 2... ¢2icut cP oe 115 maltose with--:: 2.222.002 Sess Sa 115, 142 mgmt With {32022224420 So ect 115 Plrysieal changesiam bumor-2222 .. 25-2245... 2 ei let secre see te ee 175 Poplar gall, Bruzve'works onte-2~ ¢ 2-22 oe <- oe els tee ee oe 18 Poplar organism: Acid fast: Sie. 2 So SER eA: 2 Lik eth set ee eee Se eer 131 @ultural characters: 2-5 s¢: -. 222 (Sea ES eee 140, 141 Plagella. ....222 222i te sees: » a CSR SRA ees See REe See oe rr 131 Gram’s staltive.- 22+ 2oseee. - 1. tele cee eee, ee oe eee 131 Imoculations!.2. sae:b ==. ss =>. 51424 ECE Eee eee eee. eee ae 91 Measurements £2.42 722 5522. - 2... 2dede Sheet ase fee ee ee 131 SPOKCS ace essa cnc ee eet: idee che ce eek eee tee 131 Potato cylinders, prowthion.-.---=-::2.2-.-22e2e oe ee ee 109 Quantitative test of bacteriaan galls... 222g 2922. 28) SSeS eee 81, 193 Qitince, occurrence of crown-gall on: :.<. 2-22: sso! 23222 oe 188 Quince organism: Acid fast.-oissesc cs. c hee 2sicteescec deeeteen tees tee eee 130 Cultural'characters®--...: .. 2-2. 2s A ee eee ‘ 140, 141 Flagella.......-- cate QR... ccectvt eeceewencete thee oe 130 Gram’s stains '. 2. sie siege... 2 ce ei cee Sender see telus 22 epee 130 Inoculations: <2 22 o.sece- skeet se cede seedees ns tee tee ee 78 Measuremenitsys . sccees . sk ccties o 258 OE oe eae 2 130 Spores: ..coectacossecaes tote ce see PULLS SOR RE Ee onion ac eee oe een 130 213 INDEX. 213 Page. PeIOeE oll FORTH iN OTPAMIAMNA 5 229 252 GETTER ES cease LUAU. UE 156, 157 Rapidly growing tissues, greater susceptibility of............. O83 iefie SUSE, 158 Hespberry,; iury due to crown-gall. .. occ 023222024 22k A eT 188 gull; infectious nature Of: 2<-.-7588 PU ee Ps A 188 Oreanism, MmoOculations. 2). 25 ss2 22s oF52 sece% SPE BUNT RNG 78 ISOINGIONS: 22222 222 7eseqeeds 2 -B cas eee le 78 PMEMERIMEMOIEUIGUEOD: 52-23 < ihc ic o's Eo one RUA MONIES ION 2 UPR Olas 142, 154 pe MARGIN Wh. oo 222825 as26 224 a2 ee ssc J USA EG, ee a 118 Redaick’s work on necrosis of the grapevine...................-...2222222--- 19 REeuen work on sall- of sugar beet! 22.022 2ST SUSE lll ee 192 MeBELIetan Ol WOE OF. ci 2s22G2 bc22 so iets se cests kts tect PW 84 Resistance of daisy to repeated inoculations. ......................2..22.... 177 oe eeey caused by crown-sall-. 2.22222 2c2 2.00 LL Lee: 189 Rose organism: REEURARES cen feos ©! SAT EY ESR a ee a RIA Soe Ate NS Morente re ee 129 WppnerANe ARRCbOTS' Yo Sos tei sass fk kt ON Dt be ELEN Yh 140 Eitan cae VEL ae CMM Sa srs yee sees 258 oie ERE SE 129 eeRIPUtnE Ra Ne Sees 54 See SS Sn 8 a Se ans + 5k MI 129 co] LST se Se el Ag len Relea Berg tee Sh eRe Be is oi | A 75 MPECINGD A725 2525 55.23 454: ees ee Sr 129 Serene esate tor 22S 2 S52 ee halt | ATES Re aap eae ee APES oe aN 129 Rose tumor, attributed to Coniothyrium...... SOREE a sere eee a neh nf 2, 18 nuclei, two in a cell....... Seed oo es Rae Care ie It PRN gC Oe en e 160 Seana AO eHeRID LION OFS sean. 555s oes Ae eRe IY LEE 17 2 SLT OP GIR CS Actes SIS I LA Sie ahh he eA, kee pila ge 158 SALE) DELL ST] RNA 10) 7 I ae aig ee iy tee icc Ak oo be Rea aca i 105 Salsify organism: SSL The Bin Sas Seed ele eR eee Meigs Wm bee ape Citak as 132 Mere RUTAC LCE Co e> 240 45092 oes te ta bd es RE, Seeley LW 140, 141 2 LEE, oe SE een et tel te se eee pedi Beer tek 132 PememmnsetH ty Sew Ae ES oRS 8 See ee eee eee eee Oe ie 132 PR PECNIDHaEss mtfen Ree SA ANS AG 2 tes See Na vee ly oe CTP RY PT 105 ool DTG FEAT a eee, 2 See RE RS ete le eat ee de 132 Rem CE Wine ere es Ae ee, 3. el ee ek | 132 S/O SS SR ie Rear coal ae ee ESE pani te Seine cho a ee ptm ge Binet let 15s Salt bouillons, growth in........ Bete eve sh, 2 Ae eR ARE tl ate 114,144 pamomata, likeness of crown-gall to... -2-.225. 22222220 .5.0.0 2. 2 161 SeeeeePMene TIP ton" OL, tose. GamOrs s/c! 262 827 2 Le 17 Scar tissue, susceptibility to crown-gall................... . £49 eee 165 Semayvexerron-of calls, ineficiency of .. 22.0... 25220222. 2..- SE 184 infection of peach following galled raspberry..................-.------ 188 eee tn reese THipNT yt eee een lee Ss UR eee ek 22 ot oes 9 184 COEDS Gy ee DE SA I Ie sen a elt 19 Shade trees, occurrence of crown-gall on............-. ES AAS SRR oa ip tee 195 Pemecarectiy nero ih One 2 a0ne ssc na ke hs oe ee eee, 2 TLS fr RD 1138, 156 Sammons, almond trees; letter on, injury to..: 22122220) 22.20 022.0202. 184 Slow-growing tissues, lesser susceptibility of....................2.-.--2------ 158 Sodium chloride, involution forms produced by................. a fiashess atic dee 168 TONCEADIOM OL. 2) See nthe oe SRE SS LN ™ Ss 4! 8 eR 114, 144 FECOTOLG, LOCTA GION. OF. 2 ae e4e OFS eR SS eh en Bap A hela: 117, 143, 144 Som eall-of apple, relation of, to hard gall. 22. 2222.2.:5.222002...0....-.128)) 95 213 214 CROWN-GALL OF PLANTS. Page. Spil, feed infectad through). «50. 00. 62 ss casecicanc nscale PRES Ree ee 186, 188 Species, varieties, and races of the crown-gall organism, discussion of question of. 157 Spissr, sugar-heet gall, work on-.-.....:.......-.-n,ihesebeebs ep 18 Strohmer and Stift: Chemical analysis of crown-gall..............--.....-.--- 173 Structure of tumors... 2205 ieee s. 222. aen,- 3s thee ses Se eens ae 159 Sugar-beet gall, isolation from... ... nein Sieretaipaitertcnt- feast iets g iat ieee 81 Sugared peptone water, growth in... ....-...----- thie. - -eppeeee 19 Treatment, mephods' ol: - ices... <<... 9200 see cs oes o sia de 2s oe 196 Trevisan’s description of Bacillus ampelopsore..............-...-.---------- 15 Tuberculosis of beets: |... 2. . 2 22226 eh eee oo oe 194 Tormip pall, isolation from’... + -<<2---.<2.-2-22525-> 42--<-e rr 105 Turnip organism: INCIG RSE Se oS2e Sa ee Vinee = ante am ger she eee 132 aCultural characters... .... 22.2 2.2325 ese is Ol eee 140, 141 Wlapella.. 55. Jee ~ - pew tee se oo ee 132 Gram’ s Blam: 252505 2232 5. 23k owe = Se a pe 132 Tnoculationa = 2 222225225 2+ = 2252 5-1b a5 aaee—t ae 105 Measurements: 2.2.25: 5. 2+ 2-52-90 2 =e ope ite oe 132 Pathogenicity »22.22-< 42s - =< «...2dse42 3 See ee ee 132 NPores'. 22... Soke eS. ee eee see Oe Bee = 132 Myloses..0-- 22 oe 2s cor sen ete es eae Beene oe Se Oe oe 163 Unfruitfulness of trees attacked by crown-gall.............---.--------!----- 17%. Urea and dextrose in river water, erowth In..:.....-..-.-.-)5--35=eeeeneeee 153 Uschinsky’s solution, growth im... .-..- <2. a.eciict sey -~ see ee ee 114 -++-peptone, growth in... . - .. 40-2226 sampem sad eee 147 Varieties of crown-pall Gipanism... . . 22.4 3.5. i --- <= eS ee 157 Veretative'cells: < — Somme. 2. Saw Hohnel, F. von, on the geographic distribution of Lenzites sepiaria..........- 9, 37 Hornemann, J. W., on the geographic distribution of Lenzites sepiaria........ 9, 31 Inoculations with Lenzites sepiaria, experiments upon living and freshly felled treGS 25 io Le eee = - - Boe ee See sees eee 14, 19-20, 24, 30, 40 Introduction to bulletin... .-- oie dace news a coe sesh Ops eee 7-8 Tron, compounds, use in preserving timber from decay..--.--.--------------- 29 Jaap, Otto, on the geographic distribution of Lenzites sepiaria............--- 9, 35, 37 214 — a ea FF EE i INDEX. 43 Page. Jacquin, A., and Bigeard, R., on the geographic distribution of Lenzites sepiaria. 9,34 Juniperus, wood attacked by Lenzites sepiaria.......-.......-------.-.--- 11-12, 30 Karsten, P. A., investigations of Lenzites sepiaria................- 8, 9, 12, 14, 31, 33 Kickx, Jean, on the geographic distribution of Lenzites sepiaria.............. 9, 32 Knight, O. W., and Harvey, L. H., on the geographic distribution of Lenzites EEE is ha Se As ee ee Gi a etc devs ae 10, 34 Kops, J., and Trappen, J. E. van der, on the Beas distribution of Lenzites co ds SE Be ES ie ae nt ce ie ae eae 9, 31 Kraemer, H., on the use of sulphuric acid 9 Be BeRINPICUEE 5.8 fe sel ib le 19, 36 Langlois, A. e. on the geographic distribution of Lenzites sepiaria.......... 10, 33 Lanzi, M., on the geographic distribution of Lenzites sepiaria................ 9, 35 Marta ao. hosts of Lenzites:sepiarias . -..25-322252-------.-....----.. 11-12, 13, 28°30 See also Tamarack. Lentinus lepideus, distribution, as related to Lenzites sepiaria Ue ese Lenzites betulina, vitality as compared with Lenzites sepiaria.....--........- 15 , saepiaria, synonym for Lenzites sepiaria -....--.-................-- 14 Beotaria, character ds .a,saplopiytes 2 csese4. 2.222 vle eli. e eee 13, 20, 30 enitural experments i. Sees see.) iets s ls. es 18-20, 24, 30, 40 CLOUONUE MMIpOni Meer ater Se ee oe ein eS 8, 30 BEOerAp Nic GISiRtOINAON: += eee 22's). See ss 7, 8-11, 30 IMGCMALIOOLEXpPenlMeHise= Men jae ==. ce ees 14, 20, 24, 30, 40 kandsioi wood subject tomtiack==—) 2... .. 2.2.22. 7, 8, 11-13, 30, 40 UnGGie Mb Tee eS te NAGE Bena 2 5 eh errs © 7-8, 31-37 methodol entrance! += sesame ees ccc esa as = 13, 14, 20, 30, 40 occurrence on wood of deciduous trees.............-.------ 11-12 trees apparently alive..........-- 12-13, 30 ParastisM: mea 2) 0 ese a een == i a oe 13, 20, 30 PALCTOMOTOW Uae ee ene. tees 14, 16-17, 20, 30 BepRtiveness toulkaline media. eee... - 2252. 6.oen8 See 19 SD OLCR GMAT Chek erm senna. en Fe 17-18 SPRUMEaMONEr ee Oe aera = 22s: 2 KSLA 18-19 sporophores, character and development........-.---..-. 14-17, 40 TNO AN Rs Sc Se ee eee eer ae OS See anc eee ee 14 value of timber annually destroyed...-.....--....------..- 8, 30 Wnlmlbiie es somes cacacas Sane qyoSn > oe 15-16, 26-28, 30 vialis, usualiy found only on wood of deciduous trees.......-.------ lil Lenzitina saepiaria, synonym for Lenzites sepiaria ...........-..-.--------- 14 Léveillé, J. H., and Paulet, J. J., on the geographic distribution of Lenzites BEIT. cheat one ste Gon on oa COS e CONS e Bap oee ace ao. 9, 32 Libocedrus, probable host of Lenzites sepiaria.........i--.....-------.------ i Liebenburg, von, on the use of sulphuric acid as a fungicide. . ......--..----- 19, 32 Lloyd, C. G., on the geographic distribution of Lenzites sepiaria.. 9, 10, 11, 35, 36, 37 Lodeman, E. G., on the use of sulphuric acid as a fungicide ...........---.--- 19, 34 Longyear, B. O., on the geographic distribution of Lenzites sepiaria.........- 10, 35 Lucand, L., and Gillot, F. X., investigations of Lenzites sepiaria......-.-. 9,12, 33 McAlpine, D., investigations of Lenzites sepiaria...........-.-..---------- 9, 12, 19, 34 Magnus, P. W. , investigations of Lenzites seplaria_....-.-.....-.----------- 9, 34,36 Dalla Torre, K. W. von, and Sarnthein, L. von, on the geo- graphic distribution of Lenzites sepiaria..............-.-.--- 9, 36 Matruchot, L., on the geographic distribution of Lenzites sepiaria.-.....-.-.--. 9, 35 Merulius sepiarius, synonym for Lenzites sepiaria................----------- 14 Meyer, B., Gartner, P. G., and Scherbius, J., on the geographic distribution of LLG THESE OMNES So cde cae abUrO Soe SS CROSS SoA OS 3 ere ese Yeon! 214 44 TIMBER ROT CAUSED BY LENZITES SEPIARIA. : Page. Millspaugh, C. F., and Nuttall, L. W., investigations of Lenzites sepiaria.. 11, 12, 34 investigations of Lenzites sepiaria..............-....... 11, 12, 34 Moffatt, W. S., on the geographic distribution of Lenzites sepiaria............ 10, 37 Moore, J. P., and Harkness, H. W., on the geographic distribution of Lenzites ROPIANA oad Sen ek kee sin fete 20 mt elstde w= Wanita ce 10, 32 Morgan, A. P., investigations of Lenzites sepiaria......................... 11, 12, 33 Murrill, W. A., investigations of Lenzites sepiaria..............-. 9, 10, 11, 14, 35, 36, 37 Mycelium, Lenzites sepiaria, character ..........-..-.220s0scce-e] a: 15, 17, 27 Nelson, J. M., on the methods of preserving timber from decay............... 28, 36 Neumann, J. J., investigations of Lenzites sepiaria...:.............-...-- 11, 12, 36 Neuweiler, E., on the geographic distribution of Lenzites sepiaria............ 9, 36 Nitardy, E., on the geographic distribution of Lenzites sepiaria............... 9, 35 Nuttall, L. W., and Millspaugh, C. F., investigations of Lenzites sepiaria.. 11, 12,34 Oil, Beaumont, use for preserving timber from decay..........-.-.......---- 29 Oliver, Paul, on the use of sulphuric acid as a fungicide.............-.-.---- 19, 33 Oudemans, C. A. J. A., investigations of Lenzites sepiaria................- 9, 32, 34 Pabst, G., on the geographic distribution of Lenzites sepiaria............-.-. 9, 32 Paulet, J. J., and Léveillé, J. H., on the geographic distribution of Lenzites RCIA <6 ten a ae oes cee eet east ewes Cee en eee ee 9,32 Peck, C. H., investigations of Lenzites sepiaria............... 11, 12, 32, 33,34, pone Perdrizet, T., on the geographic distribution of Lenzites sepiaria............. 9, 32 Persoon, C. H., investigations of Lenzites sepiaria...............------------ 9,14, 31 Phloroglucin, use with hydrochloric acid in testing rotted wood..............- 23 Picea spp., hosts of Lenzttesisepiaria ~..220:<2 se oan se = 2 pene eee ee 11-12, 13, 30 Pine, loblolly, treated and untreated, durability tests..................------- 28-29 longleaf, inoculations of Lenzites sepiaria........................--. 13, 20, 40 treated and untreated, durability tests...............-....... 28-29 shortleaf, treated and untreated, durability tests....................---- 28 Pinus echinata. See Pine, shortleaf. palustris. See Pine, longleaf. spp.,-hoste of senaites sepiaria._.-......-.09-+.2 eee ee 12, 28, 30, 40 taeda. See Pine, loblolly. Plates, description..2-..-cs=. - --=<.scsc-sa=-Secceph ea eee eee 40 Pollini, C., on the geographic distribution of Lenzites sepiaria..............-.--- 9, 31 Polystictus veriscolor, presence on hemlock ties under test for Lenzites sepiaria. 28 Populus spp., hosts of Lenzites sepiatia-..-.22.5.-..22 2.2. 12, 30 Potassium permanganate, use in testing rotted wood ............------------- 23 Pseudotsuga spp-, hosts'of Lenzites. sepiaria. ..:....:-.2.22-:+:----- 22) 12, 30 Quélet, L., on the geographic distribution of Lenzites sepiaria............-.----. 9,33 Rabenhorst, L., on the geographic distribution of Lenzites sepiaria-...-......... 9, 31 Ranojevie, N., on the geographic distribution of Lenzites sepiaria.........-.... 9, 35 Resorcin, use with sulphuric acid in testing rotted wood............---------- 23-24 Rick, J., investigations'of Lenzites sepiaria-./.2..2) -2. 21 2. .22 222-2 eee 9, 11, 35 Ricker, P. L., on the geographic distribution of Lenzites sepiaria...............- 10, 35 Rohling, J. C., on the geographic distribution of Lenzites sepiaria...........-- > Vee Rostrup, E., on the geographic distribution of Lenzites sepiaria............-..-- 9, 35 Roth, Filibert, on methods of preventing decay in timber..............-.---- 27, 34 Ruffieux, Louis, on the geographic distribution of Lenzites sepiaria............ 9, 35 Rumbold, C., investigations of Lenzites sepiaria......................-. -- 15,19, 37 Saccardo, P. A., investigations of Lenzites sepiaria............--.-. 9,11, 12, 32, 33, 35 Salix spp., hosts of Lenzites sepiaria. -:=.-2..2.-.402-e0e eee 12, 30 Sarnthein, L. von, on the geographic distribution of Lenzites sepiaria......... 9, 35 214 INDEX. 45 Page. Sarnthein, L. von, Dalla Torre, K. W. von, and Magnus, P. W., on the geo- Braphic distribution of Lenzites sepiaria._..22..-< 6.2222. 0ccse eee eens esee 9, 36 Schaeffer, J. C., on the geographic distribution of Lenzites sepiaria........-..- 9, 31 Scherbius, J., Girtner, P. G., and Meyer, B., on the geographic distribution of [Li SMNWAVGSNSS Oa ee nesias SOROe Ee o> pe oiee hee ic eS ae A eet ats eS ra 9,31 Schrank, F. von Paula, on the geographic distribution of Lenzites sepiaria...... 9,31 Schrenk, H. von, and Hill, Reynolds, on the methods for prevention of decay OLetinrine neers eS Ae cere Presta eee NS Sete eps Maas 27, 28, 35 investigations of Lenzites sepiaria..... 9,10, 11, 12, 27, 28, 29, 35, 36 Schroeter, J., on the geographic distribution of Lenzites sepiaria............-- 9, 33 Schweinitz, L. D. von, on the geographic distribution of Lenzites sepiaria.... 11, 31 Seanonmnoson timber, objects:attammed =. 225.22 -eessaes-bee-- sees sce se ese 27, 28, 30 Secretan, Louis, on the geographic distribution of Lenzites sepiaria..........-. 9,31 Bemderr probable host of Lenzites'sepiaria.: <..- 22.2 02.22.2222 Fe t-2.--e ee 12 Bectumirsita, synonym for Lenzites'sepiaria...2.2..-.+--.--22+-e..--+------- 14 Seymour, A. B., and Farlow, W. G., on the host woods of Lenzites sepiaria-. 11, 12, 33 Sherfesee, W. F., on the methods of preserving timber from decay. .....---- 27, 285A Smith, C. S., on the methods of preserving timber from decay....--------- 27, 28, 37 W.G., on the geographic distribution of Lenzites sepiaria.......:-..---- 8, 34 Somers, J., on the geographic distribution of Lenzites sepiaria...........------ 9, 32 Sommerfeldt, 8S. C., investigations of Lenzites sepiaria .......------.-.----- ye ail Sowerby, J., on the geographic distribution of Lenzites sepiaria-.-.......-.------ 8, 31 Spaulding, Perley, on the presence of Lenzites sepiaria on wood of living trees.. 12 36 use of sulphuric acid as a fungicide...........---..- 19; 37 Specimens, Lenzites sepiaria, location in cabinets, explanation of arbitrary signs. 8 Spegazzini, C., on the geographic distribution of Lenzites sepiaria........------ 9, 35 Spirittine treatment for preserving timber from decay.....-.....--..-------- 28 Sporophores, Lenzites sepiaria, character and development... . ....... 14-17, 20,30 modification, curious example......-.---.-.:. 17 Sprague, C. J., on the geographic distribution of Lenzites sepiaria .........-.-- 10, 32 Stevenson, John, on the geographic distribution of Lenzites sepiaria......--- 8, 33 . Strasser, P. P., on the geographic distribution of Lenzites sepiaria. ........... 9, 35 Samay OH omen ae oe eee eres cues aaa ee Seco 5 ree eres 29-30 Tamarack, treated and untreated, durability tests _..........--...---------- 28-29 faxodcun, probable host of Lenzites sepiaria: .— ...22.-..-.-....----+------ 12 Temperature, effect upon growth of wood-rotting fungi.........-.-..-------- 26,30 ene poime efiect upon situcture-of wood 22 22-2222: .---. +2 2-22 seen ees 21-22 chemical, effect in preserving wood from decay......-.--- 19-20, 23, 24, 28-30 Maule’s potassium permanganate, reaction upon rotted wood. ........-- 23 microscopic, of the host woods of Lenzites sepiaria..........---.----- 23-24, 30 Tinian sulphate, reactiom upon rotted wood ..<...-22252-.....------.------- 23 Thesleff, A., investigations of Lenzites sepiaria..........--...----------- 9,11, 12, 34 Siti probable host of Lenzites sepiaria---.22:5-522--24--.-..---.---2-55-5- 12 Thiimen, F. yon, on the geographic distribution of Lenzites sepiaria.........- 9) 32 Tiemann, H. D., on the methods of preserving timber from decay..........--- 27, 36 Ties, railroad, coniferous, relation of service to Lenzites sepiaria... 7, 8, 20, 28-29, 40 Timber, coniferous, subject to attack by Lenzites sepiaria.......... 7,8, 11, 28-30, 40 decay. cd maestnu chon adwiSed Ger {sae sees Sees: <2 <= cals reine 16, 29, 30 treatment with chemicals to prevent decay ..-:-...--..---------- 27, 28-30 MmimcaLedeslenc thon SehviCes sss a= ee eee @ = = 2c ace Se 7, 8, 20, 28-29 Valen ciiun tae United statessnel G08esesseeseeiesy- «= .- soc c0ce ele 7, 8, 30 214 46 TIMBER ROT CAUSED BY LENZITES SEPIARIA. Page. Trappen, J. E. van der, and Kops, J., on the geographic distribution of Lenzites BOPIAI Aisa ac ua aes RE eld oc Bete sae Cin ELE ee a ee ene ne 9, 31 Tstiga app., hosts'of Lenzites sepiaria.....2... /siises cease se aeeee eee ae 12, 13, 28, 30 Sce also Hemlock. Underwood, L. M., and Earle, F. 8., on the geographic distribution of Lenzites BEPIATIA «0. Give Ua CORR eS Hb she J aa ee ee ee ek a ee 10, 34 Vleugel, J., on the geographic distribution of Lenzites sepiaria os hee Ge 9, 37 W: shee: Georg, on the geographic distribution of Lenzites sepiamia........ 9, 31 Water, effect of supply upon growth of wood-rotting fungi............ 22, 26, 27-28, 30 Webber, H. J., on the geographic distribution of Lenzites sepiaria............ 10, 34 Weiss, H. F., on the methods of preserving timber from pmb 2g See 28, 36, 37 Wellhouse, process for preserving timber from decay.. Ly 2 dend ee White, E. A., on the geographic distribution of Letvitess: sepia Er 10, 36 V.S., on the geographic distribution of Lenzites sepiaria.............. 10, 35 Winslow, C. P., on the methods of preserving timber from decay............- 29, 37 Winter, G., on the geographic distribution of Lenzites sepiaria................ 9, 33 Wood, decayed, appearance, external.................-...--..-.---.---... 2020,40 internal... j.388. 282 2 ee ee 21-22, 30 microscopic examination, as related to Lenzites sepiaria............ 23-24, 30 Wulfen, F. X. von, first to name Lenzites sepiaria.............- v+ieS See 14, 31 Zinc chlorid, process for preserving timber... 52... ---+. 29.2225. neee eee 28-29 chloriodid, reaction upon wood rotted by Lenzites sepiaria.............- 23 creosote, use in preserving timber from decay.........---.-.....-------- 29 tannin, use in preserving timber from decay..............-------------- 29 Zoebl, A., on the use of sulphuric acid as a fungicide.......-......--....... 19, 32 Zon, R., on the methods of preserving timber from decay.......-..-.-- ae Diaae 214 0 wa DEPARTMENT, OF AGRICULTURE. BUREAU OF PLANT INDUSTRY—BULLETIN NO, 215. B. T. GALLOWAY, Chief of Bureau. \ AGRICULTURE IN THE CENTRAL PART OF THE SEMIARID PORTION OF THE GREAT PLAINS. BY = J. A. WARREN, Assistant Agriculturist, Office of Farm Management. Issump JuLty 19, 1911. WASHINGTON : GOVERNMENT PRINTING OFFICE. 1911. BUREAU OF PLANT INDUSTRY. Chief of Bureau, BEVERLY T. GALLOWAY. Assistant Chief of Bureau, WILLIAM A. TAYLOR. Editor, J. E. ROCKWELL. Chief Clerk, JAMES E. JONEs. OFFICE OF FARM MANAGEMENT. SCIENTIFIC STAFF. W. J. Spillman, Agriculturist in Charge. D. A. Brodie, David Griffiths, and C. B. Smith, Agriculturists. Levi Chubbuck, A. D. McNair, G. E. Monroe, and Harry Thompson, Experts. G. A. Billings, M. C. Burritt, J. S. Cates, J. 8. Cotton, H. R. Cox, M. A. Crosby, D. H. Doane, L. G. Dodge, J. A. Drake, J. W. Froley, C. L. Goodrich, Byron Hunter, H. B. McClure, J. C. McDowell, H. A. Miller, W. A. Peck, A. G. Smith, E. H. Thomson, and B. Youngblood, Assistant Agriculturists. M. C. Bugby, E. L. Hayes, A. B. Ross, E. A. Stanford, and G. J. Street, Special Agents. ye C. H. Arnold, C. M. Bennett, and H. H. Mowry, Assistants. 215 2 LETTER OF TRANSMITTAL. U. S. DEparTMENT OF AGRICULTURE, Bureau or Piant INpustry, OFFICE OF THE CHIEF, Washington, D. C., March 20, 1911. Sir: I have the honor to transmit herewith a manuscript entitled ‘Agriculture in the Central Part of the Semiarid Portion of the Great Plains,” and to recommend that it be published as Bulletin No. 215 of the series of this Bureau. This manuscript was prepared by Dr. J. A. Warren, Assistant Agriculturist, under the direction of the Agriculturist in Charge of the Office of Farm Management, of this Bureau, who for a number of years past has been studying the management of ‘‘dry farms” and the problems confronting the farmers of the region, besides having had some previous practical experience there. The author wishes to acknowledge his indebted- ness to Mr. J. E. Payne, superintendent of the experiment station at Akron, Colo.; Prof. W. P. Snyder, superintendent, and Mr. W. W. Burr, assistant, of the substation at North Platte, Nebr., each of whom has read the manuscript and offered valuable suggestions. For some time prospective settlers have made a strong demand upon the Department for reliable information concerning this region. There has also been a strong demand from persons already located there for suggestions for the better management of their lands. This manuscript is intended to fill the former want and in a measure also the latter. Respectfully, Wn. A. Taytor, Acting Chief of Bureau. Hon. JAMES WIzson, Secretary of Agriculture. 215 3 CONTENTS. MMTROCMEMON=. 5222 --- <2 5.caron- = By ERNE A Gute eee ate Natural factors of plant growth in the Grane Pins Fane. De eens Ie ee Economic conditions in the Great Plains CEES ares eee IN ne Remain O SOMIATIO TCOTON 2c Se eon 8 ee ew nels pe beexcke EXerory of the settlement of the region.....-...... 2.22... 2.22 s2e elects Conditions that have brought about resettlement........................ PP RPNC Hees AMINE TESION. 222.5. -6S2s2< 08a eee we. fie armeniural future of the repion. .-. . 2222-22422. --. 2 n2-2-- sess lees es MEME ATICES OlOTOO Ct Seas 4.222 hoot. Wee: 52 sve e eee clos mene MamemParmoniads Ol tllages oo. ee eee kde oe eee Introduction and development of drought-resistant crops................- Pomc systems of farm management..<_:.22-252...........--------s- ao on bo bo bo bo OS Oe ILLUSTRATIONS. Page. Fie. 1. Map of the central part of the semiarid portion of the Great Plains, showing average annual precipitation....................-.-....-- 12 2. A field of wheat on summer-tilled land, Phillips County, Colo., 1909... 27 3. A summer-tilled field where winter wheat will be grown, adjacent to the field. shown inifigure 2... ....... ..s2. 2524-1243... soe2 ose ee 29 4. A field summer-tilled by listing instead of plowing, Rawlins County, Kans, 19092. Petco - =... -S¢chendede eee see 30 215 ; 6 B. P. I.—662. AGRICULTURE IN THE CENTRAL Ae Ole eiballs SEMIARID PORTION OF THE GREAT PLAINS. INTRODUCTION. Since the earliest period of settlement in this country the surplus population has migrated westward. This movement will doubtless continue till all the varied resources of the West are as fully utilized as their respective values warrant—till the return for efforts expended and the advantages to be obtained are balanced with those of other parts of the country. The relative profitableness and agreeableness of agricultural enterprises in different sections are by no means stable quantities. For this reason there must always be more or less shifting of population, but this shifting will naturally grow less as the whole country becomes more fully occupied and its possibilities more fully developed. Agriculture, like every other human activity, is not dependent upon natural surroundings alone, but is changed and swayed by every change in economic conditions. Factors in agriculture may be divided into two classes, natural and artificial, Over most natural forces man has little or no control. Artificial factors are produced and controlled by man, though not necessarily by the individual. Natural conditions are the results of forces so superhuman that man ‘may not even hope to change or modify them. All he may hope to do is to fit himself to meet those conditions and prosper under them by learning to counteract the adverse effects, to supplement defi- ciencies, and to make the most of every favor nature grants. Climate and soil are the total natural agricultural resources of any country. Favorable conditions with respect to both are absolutely necessary to successful crop production. A fertile soil is essential, yet an infertile soil may be built up and improved; but a fertile soil is absolutely useless without a favorable climate. “ What a nation shall raise depends upon the climate of the region in which that nation happens to be located, and what is produced influences the laws, habits, and customs of the people. North America owes more to its variety of climate than to its variety of soil. A temperate climate, 92597°—Bul. 215—11——2 7 8 AGRICULTURE IN THE SEMIARID GREAT PLAINS. with its recurring periods of heat and cold, is responsible for our being the busy, hustling nation that we are.’’! Settlers in new countries, and especially in the dry regions, have often been misled by giving too little attention to climatic conditions. They have found a fertile, easily tilled soil, and without regard to climate have assumed that good crops must be the reward of cultivation. NATURAL FACTORS OF PLANT GROWTH IN THE GREAT PLAINS FIXED. Of the climatic factors, rainfall and evaporation are the most impor- tant in the semiarid region, because the most faulty. The saying that “rainfall follows the plow”’ has, in its effect, been one of the worst deceptions ever foisted upon a credulous public. This idea has been the undoing of more plains settlers than has drought itself. If the people had realized that the dry country would always be a dry country many who have settled in the semiarid regions would never have gone there, and those who did go, understanding the hard conditions, might have risen to the emergency and long ago have met the necessity, as did the settlers in Utah and Washington, instead of waiting in the vain hope that Nature would take pity on them and reward their puny efforts by an increase in precipitation. Space does not permit a discussion here of the fixedness of climate, but all students of meteorology now agree that the climate is unchangeable, at least within the limits of a single generation.” There are fluctuations from year to year and more or less cyclical changes which give periods of dry years followed by periods of wet years, but the average of a long period of years is practically stable. These fluctuations, although very irregular, lie between fairly well-defined limits as regards total variation. The main factors affecting evaporation from an open water surface are the relative humidity of the atmosphere, or the proportion of moisture in the air compared to what it can hold, the wind velocity, the tem- perature of the air and of the water at the surface, and the air pressure. Evaporation from the soil, however, is affected not only by these factors, but also by the character and condition of the soil and by the plant growth thereon. Soil conditions and plant covering are largely under the farmer’s control. The soil in its native state is, like the climate, unchangeable so far as the ordinary limits of time are concerned, but under cultivation very important temporary changes may be brought about.* 1 Ball, Frank Morris, of the department of geclogy, University of Minnesota, in Monthly Weather Review, May, 1906. 2 For a discussion of this subject the reader is referred to the Yearbook of the U.S. Dept. of Agriculture for 1908, p. 289; Bulletin D, U.S. Weather Bureau; and Monthly Weather Review, May, 1906. 3See Bulletin 55, Bureau of Soils, pp. 61, 71, and 76. 215 ECONOMIC CONDITIONS CHANGED. 9 Climate,' soil, and topography? are the factors determining the native vegetation. As these factors are all fixed and unchangeable to any appreciable extent, the native vegetation is also fixed and un- changeable so far as one lifetime is concerned, except for the limited effects of overgrazing and the effect of increased or diminished burn- ing by fire. Yet along with the idea of change of climate goes the belief that the plant growth of the native prairies of Nebraska and Kansas has changed decidedly as successful agriculture has pushed its way westward. This notion prevails especially with reference to the long grasses, many believing that even eastern Nebraska and eastern Kansas were covered with buffalo and grama grasses 40 years ago, and that settlement has caused the bluestem to drive the short grasses westward 200 miles. This opinion has, however, no founda- tion infact. When the Plains were first settled there were no elements in the flora that had not assumed their proper places. Neither the long grasses nor the short grasses were newcomers. Both had fought the battle for supremacy and each held its chosen ground—the ground which it still holds, except as overgrazing or burning has disturbed the equilibrium. If the stock is removed, the floral covering even on the overgrazed land again assumes its original character, showing conclusively that the character of the plant growth is a fixed resultant of natural causes and is not determined or changed by any obscure and intangible force following in the wake of civilization. The appearance of the prairies changes noticeably in wet seasons. The wheat-grass and other tall grasses and weeds are much more in evidence, the buffalo and grama grasses grow much taller, and annual plants are more conspicuous; but the real and permanent characters of the flora are unchanged by even half a dozen wet years. The relative sizes of plants, but not the kinds of perennials, change with the season. The same native flora which existed on the Plains when they were first settled occupies them to-day; the same climatic conditions which caused the ruin of the early settlers must be met by the settlers of to-day; the same soil conditions which the homesteader then found confront the ‘‘dry farmer” of the present; the same grass mixture which pastured the first homeseeker’s stock and in some cases fur- nished hay for the winter is still there. As man has not changed the climate, neither has he changed the plant growth on the prairies. ECONOMIC CONDITIONS IN THE GREAT PLAINS CHANGED. What has just been stated is not that the farmer on the semiarid Plains to-day has the same combination of conditions to meet that he had 25 years ago when the region was first invaded. It has 1See Bulletin 55, Bureau of Soils, pp. 31 and 35. 2Tdem, p. 30. 10 AGRICULTURE IN THE SEMIARID GREAT PLAINS. been pointed out that agricultural factors are of two classes, natural and artificial, and one of these sets of factors is as important as the other. It is just as essential to have a market as to have a crop. While the forces of the first group are fixed, those of the second are constantly changing. Whatever differences there may be between the conditions that surround the settler on the dry lands to-day and those that faced the settler of a generation ago on the same land, these differences are not in soil, climate, or native vegetation. They are economic and industrial differences—differences in the machinery available, the methods of cultivation practiced, the varieties of crops at hand, and the prices of products. The changes in these respects are great, so great that the total combination of all conditions make, as it were, almost another country. The improvement in machinery is so great that Prof. Snyder, of the substation at North Platte, Nebr., has said, ‘‘Take away the disk, the press drill, and the corn machinery and western Nebraska would still be a place for the cattleman.” A parallel statement with regard to the crops that have been intro- duced during the last 15 years may be made, but great as is the effect of these changes the advance in prices of products is of still greater importance. Where success has been attained it has in almost every instance been due to more than normally favorable seasons combined with high prices. There does not appear to have been any great and general revolution in methods of cultivation except what has been brought about by the introduction of new machinery. In spite of the fact that many periodicals have published glowing accounts of a wonder- ful revolution in methods that has turned the dry region into the most prosperous of farms, there is little foundation for such stories. Other- wise than to use new machinery, the average farmer of the dry country has improved his practices but little. His increased prosperity is.due more to unusually favorable seasons and to high prices of grain and stock than to better methods of cultivation or management. Nevertheless, a very few exceptional farme: ;, unusually progressive men, who study their work and the conditions to be met, have changed their methods radically and have met with better success. EXTENT OF THE SEMIARID REGION. Some writers and experimenters consider the semiarid region as including all the Plains as far east as the ninety-eighth meridian, and thus include a large area of land receiving an average of as much as 27 or 28 inches of rainfall annually, which has supported a prosperous agricultural population for a generation, and in many portions of which farms are readily salable at $70 to $100 an acre. Some of the greatest winter wheat, corn, and hog producing counties in Kansas 215 PRECIPITATION. idl and Nebraska lie west of this line. To include this territory seems manifestly unjust and misleading, if it does not make the term “semi- arid”’ actually meaningless. It is impossible to fix a positive and definite line on the one side of which we shall say the country is humid and on the other semiarid, or, as some prefer to say, ‘‘subhumid,”’ for there is no sudden dropping off in precipitation, but a fairly uniform decrease from east to west across the two States. As generally used, the term refers to a country receiving an average of between 10 and 20 inches of melted snow and rain annually, but in determining aridity or humidity evaporation is of equal importance with precipitation. In southern Texas much more than 20 inches of precipitation may be required to make a humid country, but 20 inches of rainfall in the Red River region of North Dakota makes a distinctly humid climate. With reference to Kansas and Nebraska the writer prefers to consider the western limit of 20 inches average annual precipitation as the eastern limit of the semiarid region, although in southern Kansas this limit may be too far west and in some other places too far east. Sc far as the records for Kansas and Nebraska now show, this line in most places lies 20 to 30 miles west of the one hundredth meridian. The accompanying map (fig. 1) shows the region to which this dis- cussion is intended to apply and the average annual precipitation as shown by records of the Weather Bureau. CLIMATE. The climate of the Great Plains region has been thoroughly dis- cussed by several able writers and for that reason it seems unnecessary to give more than a brief summary here. It is a region peculiarly subject to high winds, driving storms, and sudden changes in tempera- ture. The light is intense and the air usually very dry. At least in a large proportion of it hail is of frequent occurrence and does much damage to crops. The native flora and even the soil! attest the gen- eral dryness. To the careful student of nature these tell a story of perennial dryness over which the myth of changing climate could have no appeal. PRECIPITATION. All plants for proper development require a reasonable supply of plant food m available form, favorable temperature, an adequate supply of moisture, and an abundance of sunshine. Given a fertile soil, the yield of the crop depends upon the relative distribution of heat, moisture, and light throughout the season. But a chain is no stronger than its weakest link. Given favorable conditions with respect to all the foregoing except one, that one becomes the limiting factor of success—the all-important question. In most of the Great 1 Bulletin 55, Bureau of Soils. ho — | 12 AGRICULTURE IN THE SEMIARID GREAT PLAINS. 102° 101° 100 WS LEN TINE : Gy River LAK. A bis : poe SE BACA_}% LE I.KNWOYVY OTERO} BE ANJMAS j WY SPRINGFITELDO . ' BACH AELONS REN 6 ' YY SHOG. NMEA = tl, ON Q s== 9 Trees, cultivation in semiarid region.....-.-:22-.----=2----=-5--=5 == eee 38 Unit, farm, in the semiarid region: .:..:.....250-.45- cee 6---=— =e 34 Utah, moisture conditions relative to plant growth......----.--------------- 14 Vegetation, native, determining factors in the Great Plains region... -.......-- 9 215 INDEX. Water, factors affecting quantity used by plants................. irrigation, in the semiarid region. ......................- needs for plant growth in the semiarid region............. Kharkof, cultivation in the semiarid region macaroni. See Wheat, durum. spring, cultivation in the semiarid region................- Turkey Red, cultivation in the semiarid region winter, cultivation in the semiarid region. Wind, effect on agriculture in the semiarid region Windbreaks, uses in the semiarid region 215 O Wisconsin, moisture conditions relative to plant growth.........-. 43 Page. 14-15, 16, 17-19, 26 Soe ee 17-18 Rao eee 26 Wheat, durum, cultivation in the semiarid region. ............... te 4 tite 23, 32, 33 Seis /g.a5 aecia’s ol Stay rare 2 ag 3.3 23, 31, 32, 35, 36, 3 5-1 Bul. 216, Bureau of Plant Industry, U. S. Dept. of Agriculture PLATE |. Stem RUST OF WHEAT ON WHEAT CULMS, SHOWING VARIOUS DEGREES OF ATTACK. Des DEPARTMENT OF AGRICULTURE. BUREAU OF PLANT INDUSTRY—BULLETIN NO. 216. B. T. GALLOWAY, Chief of Bureau. THE RUSTS OF GRAINS IN THE UNITED STATES. BY EK. M. FREEMAN, Collaborator, AND EDWARD C. JOHNSON, Pathologist in Charge of Cereal Disease Work, Office of Grain Investigations. In Cooperation with the Minnesota Agricultural Experiment Station. Issuep Aveust 15, 1911. = S70 Comments CATION nT SS WASHINGTON: GOVERNMENT PRINTING OFFICE, 1911, BUREAU OF PLANT INDUSTRY. Chief of Bureau, BEVERLY T. GALLOWAY. Assistant Chief of Bureau, WILLIAM A. TAYLOR. Editor, J. E. ROCKWELL. Chief Clerk, JAMES E. JONES. GRAIN INVESTIGATIONS. SCIENTIFIC STAFF. Mark Alfred Carleton, Cerealist in Charge. C. R. Ball, Charles E. Chambliss, and H. B. Derr, Agronomists. Edward C. Johnson, Pathologist. H. J. C. Umberger and H. F. Blanchard, Assistant Agronomists. Cecil Salmon, Physiologist. John F. Ross, Farm Superintendent. A. A. Potter, Assistant Pathologist. E. L. Adams, Manley Champlin, V. L. Cory, and H. V. Harlan, Scientific Assistants. F. R. Babcock, Assistant. L. C. Burnett, P. V. Cardon, J. M. Jenkins, Clyde E. Leighty, and Clyde McKee, Agents. 216 2 LETTER OF TRANSMITTAL. U.S. DEPARTMENT OF AGRICULTURE, Bureau oF Piant Inpustry, OFFICE OF THE CHIEF, Washington, D. C., March 25, 1911. Sir: I have the honor to transmit herewith a technical paper enti- tled ‘‘The Rusts of Grains in the United States,’’ by E. M. Freeman, Collaborator, and Edward C. Johnson, Pathologist in Charge of Cereal Disease Work. This paper embodies the results of recent research by the Office of Grain Investigations in cooperation with the Minnesota Agricultural Experiment Station into the distribution, relationships, physiology, and life history of the important grain rusts, and gives much new information on the ‘‘biologic forms” of rusts, vitality of successive uredo generations, wintering of the uredo generation, and climatology in relation to rust epidemics. Former experiments on rust prevention are summarized and methods of selection and breeding of grains for rust resistance indicated. The grain rusts continue to be of large economic importance, and as this paper is another step advancing our knowledge concerning them I recommend that it be published as Bulletin No. 216 of the series of this Bureau. Respectfully, Ws. A. TayYLor, Acting Chief of Bureau. Hon. James Witson, Secretary of Agriculture. 216 3 a ot CONTFENFES. Page REMUS oa rare oes Set 5, Soca UD PS NI ale Dw 9s ERS ORI 7 meeeion rusia im the- United Sitites: . 4.22 sen c.iws si. 2 25 oe ces eee ee 8 mereiition oa: rusts in the United States... 22... -------2-5 +52 oe see onde 8 Se eee IR ReTNE Me 0 soc cece as sera us ea tas os aoa oe S Mees 8 SIBRIORL NLA bO GUS. Scr ea Soler eee Sp taew= sl ne a = A Sp 9 Diswibution: of the different rust species. ........---.- 2... 22220-22522 9 SIGIMsrinpaie Wheat s as sses been as ee 53 Methods of dissemination... .-........55..¢s. 0.00 «3 0ew sete ee ee 53 Viability ‘of ‘the uredospore......-..¢ 2.3. 2c 2 eee «66S First appearance of rusts in the spring. ; ..........s.-..<-es20--6-==<053——eee 55 Eipid @MiiGn: i. Sastes <0 ks sage =- 002 S oss Soe esis ee eee eceeee ere ee ee 58 General CIsCOAORGS. ae es Ee EE SRT 83 ILLUSTRATIONS. PLATE. Page. Puate I. Stem rust of wheat on wheat culms, showing various degrees of attack < 2222 scasse%-25i daceeneeeee ee ee eee Frontispiece. TEXT FIGURES. Fic. 1. Precipitation chart, showing the average monthly departure from normal in several States in 1903, 1904, and 1905..............-..--- 62 2. Temperature chart, showing the average monthly departure from normal in several States in 1903, 1904, and 1905..........-..---..-- 65. 216 B. P I.—665. THE RUSTS OF GRAINS IN THE UNITED STATES. INTRODUCTION. That rusts are among the most serious diseases of grains in the United States is generally granted. As they are always present in humid grain-growing districts to a greater or less extent, it is almost impossible to make accurate estimates of the damage caused by them. Estimates are, perhaps, more often too low than too high, so that the losses of fifteen to twenty million dollars annually, estimated by Bolley (28,! p. 615) for the United States, certainly seem within reason. Numerous references to losses from rust epi- demics in different countries may be found. The most severe epidemic in the last decade occurred in the United States in 1904. It was particularly prevalent in the spring- wheat belt of the northern Mississippi Valley, where the three States, Minnesota, South Dakota, and North Dakota, in which the bulk of the hard spring wheat of the United States is raised, suffered per- haps more than any other section of the country. Table I shows a comparison of the wheat crop in these three States for the years 1903, 1904, and 1905, affording a basis for an estimate of the losses sus- tained in this epidemic. Taste I.—Wheat crop in Minnesota, South Dakota, and North Dakota in 1903, 1904, and 1905.* { | “ Yield | » ; Year. Acreage. | nor eae Total yield. = = = — | | Bushels. | Bushels. "IC BL o calle chee 2 Soe aa Oe ea ee 13, 167, 110 13.15 | 173,146,171 LVL] LAS Se, . ee ne a eateries ee 13, 193, 695 11.65 | 153,793, 233 LEE coe oS a IRR Ea Tae Oe eh et eccieeee 14, 069, 251 13.66 | 192,190,759 * Compiled from U.S. Crop Report. Average yield per acre for 1903 and 1905=13.4 bushels; for 1904=11.65 bushels. Reduction in yield per acre in 1904 below the average for 1903 and 1905=1.75 bushels. Total reduction in yield in 1904=13,193,695 (acres) X1.75=23,088,966 (bushels). Average price for the three States for 1903 and 1905=66.8 cents. Reduction in value in 1904 below the average for 1903 and 1905=23,088,966X66.8 cents=$15,423,429.28. 1 The serial numbers in parentheses throughout this bulletin refer to the titles in the “ Bibliography” on pages 79-82. 216 U 8 THE RUSTS OF GRAINS IN THE UNITED STATES. An average reduction in yield of 1.75 bushels per acre in 1904 as compared with the preceding and following years gives a total reduction of over 23,000,000 bushels, valued at more than $15,000,000." The greater part of this reduction in yield and consequent loss was undoubtedly due to rust. It is exceedingly conservative to put the loss in these three States in 1904 as high as $10,000,000; and when we consider the additional losses in the other wheat-growing districts of the United States the aggregate is enormous. ; KINDS OF RUSTS IN THE UNITED STATES. This paper deals only with the rusts of the small-grain crops, wheat, barley, rye, and oats, and includes the following forms:? Puccinia graminis Pers. on wheat, rye, oats, and barley, commonly known by the misleading term “black rust,’’ but more appropriately known as ‘“‘stem rust,”’ as it generally is confined more or less closely to the stem and sheath (PI. 1). P. rubigo-vera tritici? on wheat, known as “orange leaf rust,’’ or “leaf rust of wheat.”’ P. rubigo-vera secalis* on rye, known as “orange leaf rust,’’ or “leaf rust of rye.”’ P. coronata Corda. on oats, known as “leaf or crown rust of oats.”’ P. simplex (Koérn.) Erikss. and Henn. on barley, known as “leaf rust of barley.” “ . These rusts, in common parlance, are classed as stem or leaf rusts, a convenient grouping which directs attention to the chief though not exclusive location of the rust on the host plant. DISTRIBUTION OF RUSTS IN THE UNITED STATES. GENERAL STATEMENT. All of the grain rusts, with the possible exception of stem rust of rye and the leaf rust of barley, are found throughout the United States wherever their host cereals are grown. As to the distributon of the barley leaf rust, less is known, because it may have been but recently introduced into this country and appears, as a rule, late in the season. It has been reported from California, Virginia, Minnesota, and Jowa and is probably of wide distribution. Although the rusts are for the most part practically coextensive with the hosts, they are not serious in all localities. Epidemics may occur in almost any grain-growing region, but they occur less fre- quently in some sections than in others. In general, the area most affected is the valley of the Mississippi and its tributaries, compris- ing the region west of the Alleghanies and east of the ninety-eighth 1 Even comparing the yield, 11.65 bushels per acre, with the 10-year average (12.2 bushels per acre) for the three States from 1896 to 1905 (obtained by computing the averages in the three States), there was a reduction in yield in 1904 of more than 0.5 bushel to the acre. 2 A few other rusts have been reported, some perhaps by mistake and some of such rare occurrence as to be of no economic importance. Puccinia glumarum (Schm.) Erikss. and Henn., the yellow rust of wheat, which is a very common and serious rust in Europe and India, has not yet appeared in this country. ’ The trinomial terminology for these two rusts was first used by Carleton (30, p. 10). 216 DISTRIBUTION OF RUSTS IN THE UNITED STATES. 9 meridian, which marks the eastern border of the semiarid lands of the central United States. It thus includes a large portion of the great erain-growing districts of this country. The rusts are also very severe and of annual occurrence in the small, isolated districts on the west side of the Coast Range in California, in eastern and southern Texas, and in parts of the Atlantic Coast States. They are an important factor in the grain-growing regions of eastern Washington and Ore- gon. In general, where the annual rainfall is 20 inches or more, rust may be a serious menace to crops. In areas where the annual rainfall is less than 20 inches rusts are generally of little importance. Such dry areas occur in the United States just east of the Rocky Mountains, extending eastward to the ninety-eighth meridian and in the inter- mountain areas, including Wyoming, much of Montana, Idaho, Utah, Colorado, New Mexico, southeastern Oregon, and the interior valleys of California. Here in most years rusts are comparatively rare, though in the great rust epidemic of 1904 some of these areas, includ- ing California, were affected. AREAS MOST LIABLE TO RUST. The area where rust is particularly a menace is the hard spring- wheat belt of Minnesota, North Dakota, and South Dakota. The States bordering the Ohio River Valley, including Kentucky, Illinois, Indiana, and Ohio likewise are frequently attacked by rust. In the Southern States of the eastern half of the United States—that is, south of and including Tennessee and North Carolina—rust of certain cereals has been so serious as almost to prohibit the growing of them in those regions. It is very difficult, for instance, to grow spring oats profit- ably in portions of the southernmost tier of States east of the Missis- sippi River, one of the chief difficulties being rust. Almost nowhere in this southeastern part of the United States are the small grains, with the exception of winter oats, grown at all extensively. DISTRIBUTION OF THE DIFFERENT RUST SPECIES. Stem rust of wheat—The stem rust of wheat (Puccinia graminis tritici Erikss. and Henn.) is of great importance in the hard winter and hard spring wheat belts of the Great Plains area and in the States bordering the Ohio River. In Maryland, Virginia, and other Eastern States it has been almost entirely absent for many years, but is by no means unknown. In Washington and Oregon it is frequent and virulent. In the interior mountain valleys, between the Rocky Mountains and the Sierra Nevada Mountains, and in the nonirrigated western area of the Great Plains, it is only occasionally found and is seldom serious. In the interior valleys of California it is occasionally epidemic, though usually of shght importance. On the coast of California 216 10 THE RUSTS OF GRAINS IN THE UNITED STATES. it is always present and almost always virulent. Little grain is grown in this region. In the Southern States only a small quantity of wheat is grown, and here this rust is often severe. In the south- ern half of Texas it makes wheat growing a hazardous undertaking. Even in northern’ Texas it is a factor of great importance. The greatest rust epidemic of the last decade, which was due to the stem rust of wheat, occurred in 1904 and extended over the entire Missis- sippi Valley and up into the wheat fields of the Canadian Northwest, being particularly severe in the spring-wheat belt. It invaded the dry lands west of the Rocky Mountains and was severe in the interior valleys of California. A serious attack of stem rust of wheat was also experienced in the spring-wheat belt in 1902 and in 1905. Leaf rust of wheat.—The occurrence of leaf rust (Puccinia rubigo- vera tritici Carleton) is also coextensive with wheat culture. It is more common in many districts than stem rust. In the whole eastern half of the United States it is present every year, usually to a consider- able extent. Visitations amounting to epidemics are not infrequent, but the losses caused are not comparable to those of the stem-rust epidemic and are disregarded by the ordinary farmer, who accepts them as inevitable. In the Atlantic States the leaf rust is the chief rust of wheat and is very severe in some seasons. Like the stem rust, it follows more or less closely the rainfall lines, being of little impor- tance in the arid sections of the country. In the Palouse district of Washington, Idaho, and Oregon, however, it is usually abundant. Stem and leaf (or crown) rusts of oats —The presence of stem and leaf rusts of oats(Puccinia graminis avenae Erikss. and Henn., and Puccinia coronata Corda) is coextensive with the culture of that grain. The stem rust of oats, if not more harmful, is fully as destructive as the stem rust of wheat, and its distribution is somewhat similar. It is almost invariably accompanied by the leaf rust (Puccinia coronata), which is probably the most destructive of the leaf-rust group. Attention should be called to the fact that the stem rust of oats is not nearly so closely confined to the stem as is that of wheat, but is very frequently found on the leaf blades. The leaf and stem rusts of oats are usually commingled, and it is difficult to determine how much of the resulting damage is due to each. The leaf rust, however, is seldom found on the spikelets or the spikelet stems. It is here that much of the real damage is done by the stem rust. These rusts are found extensively only east of the dry belt of the Great Plains region, with the possible exception of eastern Oregon and Washington. In the Gulf Coast States, except northern Texas, and in Georgia and South Carolina they are paramount in importance and almost prohibitive of spring-oat growing, though winter oats are quite extensively grown. Proceeding northward, the rusts continue to be of great importance. 216 DISTRIBUTION OF RUSTS IN THE UNITED STATES. 1g: Even as far north as Wisconsin regions are known where oat growing has been discontinued on account of rust, and epidemics have been known to extend to the Canadian line and even beyond. Two features of an oat-rust epidemic explain instances of successful crops which often occur in the midst of an epidemic. They are (1) the great variation in time of ripening of different varieties of oats, amounting to as much as three weeks or a month in some latitudes, and (2) the apparent suddenness of the appearance of the epidemic. Frequently a variety one week later than another will be ruined by rust, while the earlier variety will escape entirely. This results in the presence every year of considerable rust, amounting to a severe attack in some localities and on some varieties, while other localities and varieties escape. Stem rust of barley.—The occurrence of stem rust of barley (Puccinia graminis hordei)* is practically coextensive with the culture of that erain, but its presence is not often a serious menace. In general, the early date of maturing of barley seems to assist this crop in avoiding injury. Barleys planted very late—for instance, those planted for fodder—are sometimes seriously attacked, while the erain barleys usually escape damage. It may be noticed, however, that this rust, like the stem rust of oats, is not so nearly confined to the stem as the wheat stem rust, but is often abundantly present on the leaves. The rust assumes more serious proportions in the Southern States. In the Great Plains area and in the dry inter- mountain districts it is comparatively rare. Leaf rust of barley —Leaf rust of barley (Puccinia simplex (K6rn.) Erikss. and Henn.) seems to be of recent introduction. It was reported from Iowa in 1896, from California in 1905, from Minnesota in 1905, 1906, 1907, and 1908, and occurred in Virginia in 1906 in a considerable degree. In 1910 it was abundant at Laurel, Md., and also occurred in Virginia. The most abundant outbreak was in Virginia, in 1906, where the plants were well covered with rust. In Minnesota it seems to appear late in the season and has had no injurious effect on the crop. It may be classed as one of the least conspicuous of the erain rusts in point of economic importance. Stem rust of rye—The stem rust of rye (Puccinia graminis secalis Erikss. and Henn.) is fairly common, but causes little injury. The explanation of this probably lies in the fact that winter rye is grown almost exclusively in the United States, and the stem rust appears at so late a date as to cause no appreciable damage. It was fairly common in Minnesota in 1906-1908 in experimental plats on spring rye, and in 1909 was abundant. As these were light rust years as 1 As shown later, the physiological specialization of this rust in the United States is sufficiently different from that of the stem rust on wheat to make a distinction in the name desirable, and the trinomial termi- nology, as here applied, is used throughout this paper. 216 12 THE RUSTS OF GRAINS IN THE UNITED STATES. regards stem rust, no conclusions are possible from them as to the possibility of epidemic visitation on spring rye. Bolley, at Fargo, N. Dak., durmg the summer of 1907, had experimental plats of winter rye in the vicinity of barberry bushes which were infected with stem rust, and these winter-rye plats were badly rusted. The rust also appeared spontaneously on greenhouse mateérial at Wash- ington, D. C., in 1906. The exact limits of the stem rust are not determinable on account of the meager reports, but it is safe to say that the rust at present is of very little economic importance. On the other hand, it seems probable that it is widely distributed in small quantities. Leaf rust of rye.—The occurrence of the leaf rust of rye (Puceinia rubigo-vera secalis Carleton) is coextensive with the culture of that grain, and is often very abundant. It is found everywhere, appearing usually in abundance on the young plants in the fall; in the spring it is ordinarily the first rust to appear on cereal crops. No damage is usually attributed to it, and probably little or none is actually suffered, for the rye matures so early and the rust is so closely con- fined to the leaves that appreciable injury is almost always avoided. As with stem rust of rye, nothing can be predicted concerning the possibilities of leaf rust on spring rye, because comparatively little spring rye has been grown in this country up to the present time. BOTANICAL CHARACTERISTICS, LIFE HISTORIES, AND PHYSIO- LOGICAL SPECIALIZATIONS OF RUSTS. GENERAL STATEMENT. Investigations of recent years have shown conclusively that botan- ical characteristics, life histories, and physiological specialization of parasitic fungi vary to such an extent with the geographical distri- bution that a sequence of forms for one locality is not necessarily the sequence for any other. This brings us face to face with the problem of rust life histories in the United States. Although the European and American forms may be apparently identical ‘morpholoeeeaiee they are not necessarily identical in their life histories or physio- logical specialization. Investigations on the rusts in this country have shown that while the work of European botanists may be suggestive it can not be accepted as conclusive or final for the rusts of the United States without confirmatory experimental evidence. Some information has been gained in recent years on the specialization of the rusts growing on the different cereals, but much still remains to be done. This bulletin represents an attempt to show briefly our present knowledge of these rusts im the United States in comparison with our knowledge of rusts in Europe. For detailed descriptions of the 216 _ LIFE HISTORIES OF RUSTS. 13 European forms the reader is referred to the works of Eriksson and Henning, Klebahn, Ward, and others, cited later in this paper. RELATIONSHIPS BETWEEN AMERICAN AND EUROPEAN FORMS. Stem rust of wheat, rye, oats, and barley.—It has been known for more than 40 years that the stem rust (Puccinia graminis Pers.) of wheat, rye, oats, and barley in Europe may pass on to the barberry, produc- ing «cidia, the cluster-cup stage, onthis plant. The same has been likewise conclusively proved for the forms in this country. That the stem rust always does pass through the barberry stage in each season’s sequence of forms, or that it can not live for more than one season without passing on to the barberry, is not only not implied but, as will be shown later, is absolutely disproved by field experience and experiment. We know that rust can live for more than one season without the intervention of the barberry, but we also know, on the other hand, that the barberry stage is not uncommon in many rust-infected districts, so that it may still be an important factor. This feature will be further discussed. Leaf rust of wheat.—The ecidial stage of leaf rust (Puccinia rubigo- vera tritici Carleton) of wheat is not known either in Europe or in this country. Arthur (5) has shown that a similar rust on Elymus vir- gimcus Li. has a very common ecidium on the jewel weed (Impatiens fulva Nutt.). It can not be stated at present, therefore, whether this rust has an ecidium in this country, or whether it has entirely lost this stage, as seems to be the case with Puccinia graminis in Australia, It is a fact easily observed in almost any wheat area of the United States, at least as far north as St. Paul, Minn., and Fargo, N. Dak., that the uredo stage exists through the winter months in the severest winters and the rust may thus live independent of an ecidial stage. Leaf (or crown) rust of oats.—In Europe the crown rust (Puccinia coronata Corda.) of oats has its ecidial stage on species of Rhamnus. The exact identity of the European and American forms may perhaps be open to doubt, though without question they are very closely re- lated. It has been shown that in Europe two species of crown rust exist (62), one (Puccinia coronata Corda.) with ecidia on Rhamnus frangula Li. and the other (Puccinia coronifera Kleb.)' with its ecidia on Rhamnus cathartica lL. Neither of these xcidial host species are indigenous to this country, although they have been introduced and grown quite extensively as ornamental shrubs in different localities. The eridia of our own rust on oats is found on R. lanceolata Pursh., 1 Eriksson on the basis of careful inoculation experiments has since separated the crown rusts into a large number of physiological species, dividing Puccinia coronifera Kleb. with its ecidium on Rhamnus cathartica into 8 physiological species and the Puccinia coronata (Corda.) Kleb. with its ecidium on Rhamnus frangula into 3 physiological species (49). 216 14 THE RUSTS OF GRAINS IN THE UNITED STATES. R. caroliniana Walt., and R. cathartica Li. The exact relationship of the American and European crown rusts can be determined only by parallel inoculation experiments with European and American forms. These have not yet been performed. Leaf rust of rye-—In Europe the leaf rust of rye (Puccinia dispersa Erikss.) forms its ecidium on Anchusa officinalis L. and Lycopsis arvensis L. Arthur (11, pp. 236, 237) succeeded once in growing the spermogonia of the American form (Puccinia rubigo-vera secalis Carleton) on L. arvensis L. in this country. It is believed, therefore, that the American and European forms are identical, but further experimental evidence should be obtained. Leaf rust of barley.— Leaf rust (Puceinia simplex (Kérn.) Erikss. and Henn.) of barley was not reported in the last bulletin on rust issued by this Bureau and seems, in fact, not to have been previously re- ported. The American form agrees in all morphological character- istics with the European form. It is chiefly characterized by the pre- dominance of the one-celled teleutospores. The teleuto stage is often somewhat scarce. The earliest collection of this rust available for examination was obtained in Iowa in 1896. It was collected in Cali- fornia in 1905. It has been noticed in abundance, especially toward fall, chiefly on volunteer or very late barley, in Minnesota during the seasons of 1905 to 1908, in Maryland in 1910, and was reported in the spring of 1906 from Virginia, where it occurred in great abundance, but, like the leaf rust of wheat, it caused little appreciable damage. BIOLOGIC FORMS. . GENERAL DISCUSSION. Rust fungi exhibit great variety in regard to complexity of life his- tories. Some are confined to single-host species, others range over two or more species of one host genus, while still others range over two or more genera and often on different tribes of the same family. This comprehensive range may obtain in addition to the alternation of host plants, asin the stem rust of cereals. For instance, the stem rust of oats passes its ecidial stage on barberry, while the uredo and teleuto stages may be found on practically all species and varieties of oats and on several grasses, some of which are not at all nearly related to oats, but are, in fact, genera of tribes somewhat removed from that of the oat (30, pp. 61-63). ‘tAttention must be called to the fact that the ranging to other species occurs most abundantly in the uredo and teleuto stages, though it is not unknown in the ecidial stage.) Fur- ther complexity arises in the following way: What may appear to the the eye, and often under the highest power of the microscope, as one and the same species of rust on a number of species, or even varieties, 216 \ LIFE HISTORIES OF RUSTS. 1d may really not be identical, since they are not interchangeable from one host to the other. For instance, the leaf rusts of wheat and rye can not be distinguished from each other under the best microscope lenses of the present day; yet the leaf rust of rye can not ordinarily be transferred by inoculation from rye to wheat and probably is not so transferred in nature. In other words, one finds here two fungi exactly similar in morphological characteristics, but physiologically different. These have been variously designated,' probably the most convenient and expressive term being ‘‘biologic forms.” It is seen at a glance that the biologic forms may complicate very greatly the rust life history. They offer great difficulties to the investigator of rusts and, at the same time, are the basis for a most promising field of work of much importance, viz, the study of rust-resistant varieties. A further complication arises from the facts obtained through experiments in various countries, which have shown that what is apparently the same species (the host being morphologically the same) may consist of a large number of strains or varieties which may behave differently in different geographic areas. The stem rusts of wheat and barley, for instance, are very similar, interchanging hosts easily and being capable of transfer to various grasses in this country. (See pp. 17-21; also Carleton, 30, pp. 54-56.) The researches of Eriksson (41, p. 70; 40, p. 294; 42, p. 500; 46, p. 198) show that in Sweden the stem rust of wheat goes with difficulty to barley and rye, while the stem rusts of barley and rye interchange hosts very easily. The chief factors in the complexity of the life history of cereal rusts may be summarized thus: (1) Alternation of hosts for different spore forms; that is, between the barberries and grasses. (2) The restrictions of different biologic forms of a single species of rust to various definite groups of host plants; as, for instance, Puccinia graminis avenae on oats; also found on Dactylis, etc., but not on wheat. (3) The variation of the biologic forms in different geographic areas. The biologic forms of cereal rusts have been somewhat fully worked out by Eriksson and Henning, Klebahn, and others for various localities in Europe. The reader is referred to these authors for more complete details (89 and 63). The forms in this country have received some attention, though scarcely as much as those in Europe. Practically the only work done in this line has been that of Hitchcock and Carleton (58) and of Carleton (30 and 31). The results of the latter agree in the main with the results recorded in this paper, but differ considerably 1 Some of the terms used are Species sorores, Schroter (94, p. 69); biologische Spezies, Klebahn (62, pp. 232, 258); biologiske arter, Rostrup (88, p. 40); physiological species, Hitchcock and Carleton (58, p. 4); formae speciales, Eriksson (40, p. 292); Gewohnheitsrassen, Magnus (69, p. 82); and biologiske rassen, Ros- trup (89, p. 116). ° 216 16 THE RUSTS OF GRAINS IN THE UNITED STATES. in some details. The tendency in recent years has been to consider the biologic forms of our rusts as somewhat closely limited to their host species. Hitchcock and Carleton (58) and Carleton (30) find the stem rust to contain the pid forms: a (L.) Pers., Fustmies ss caeilaa ( 7h ) Vill., are on nidhardetnd Schrad., Elymus canadensis glaucifolius Muhl., Elymus canadensis L., Hordeum jubatum 1.., Hordeum murinum L., Dactylis glomerata ., Agrostis alba L., and Agro- pyron tenerum Vasey. (b) P. graminis avenae Erikss. and Henn. on oats, several species, Arrhenatherum elatius (Lu.) Beauv., Hordeum murinum L., Ammophila arenaria (L.) Link., Trisetum subspicatum Beauv., Dactylis glomerata L., Koeleria cristata (1..) Pers., Alopecurus alpestris, Holcus mollis, Agrostis scabra Willd., Polypogon monspeliensis (L.) Desf., Festuca sp. indet., Phleum asperum Vill., Bromus ciliatus L., and Eatonia obtusata (Mizhx.) Gray. Puccinia graminis secalis Erikss. and Henn. was not mentioned. Eriksson (41, p. 70; 40, p. 294; 42, p. 500; 46, p. 198; 44 and 47) finds them as follows: (a) P. graminis tritici Erikss. and Henn. on wheat, sparingly on barley and rye. (b) P. graminis avenae Erikss. and Henn. on oats, Avena sterilis L., Avena brevis Roth., Arrhenatherum elatius Mert. and Koch., Dactylis glomerata L., Alope- curus pratensis L., Milium effusum L., Lamarckia aurea Mch., Bromus arvensis L., Trisetum distichophyllum Beauy., Bromus brachystachys Horn., Bromus madritensis L.., Koeleria setacea DC., Festuca myurus Ehrh., Festuca tenuiflora Sibth., Festuca scinroides Roth., Phalaris canariensis L., Phleum asperum Vill., and Briza maxima L. (c) P. graminis secalis Erikss. and Henn. on rye, barley, Hordewm jubatum L., Hordeum comosum J. and Presl., Bromus secalinus L., Elymus sibiricus L., Elymus arenarius L., Agropyron repens Beauy., Agropyron caninum R. and Sch., and Agropyron desertorum Fisch. The differences in results obtained by these European and American investigators have led the writers to examine further into the possi- bility of breaking down the barriers between the so-called biologic forms. This object, as will be seen below, has been accomplished without much difficulty, and at the same me considerable light has been shed on the true nature of the parasitism of cereal rusts. EXPERIMENTS ON Brouoaic Forms. DESCRIPTION OF METHODS. Rusts were collected in Minnesota and were transferred to their own host plants by artificial inoculations in the greenhouses at Washington, D. C. These constituted the stock rusts. In all the experiments the uredo stage was the spore form used. The cereal host plants were raised in small pots, about 10 plants to_a pot, and inoculated in the seedling stage, either on the first or on the second leaf. The spores were placed on the leaf dry, or they were slightly moistened to enable them to adhere to the leaf surface. The plants were then sprayed with water by means of an atomizer until the leaf 216 LIFE HISTORIES OF RUSTS. i ly surfaces were covered with very fine drops and then placed under large bell jars for two days. They were then removed from the bell jars to the greenhouse bench. In the accompanying diagrams, W, B, O, and R represent wheat, barley, oats, and rye, respectively.1. The succession of inoculations reads from left to right, the original host plant being on the extreme left. The figures in the form of a common fraction following each host plant are used as follows: (1) The numerator shows the number of leaves successfully infected; that is, leaves showing rust pustules. (2) The denominator shows the number of inoculated leaves. The fraction ;';, therefore, indicates 7 pustuled leaves out of a total of 33 inoculated. Again, the fraction 4 followed by the word ‘‘ flecked”’ indicates that 1 leaf out of 3 was flecked. The term flecked indicates a more or less close approach to the successful parasitism. The abbreviation ‘‘st. fl.”’ means strongly flecked. These diagrams show the results of various sets of inoculation experiments with the different grain rusts, on their own and other hosts, which have been carried on at different times. EXPERIMENTS WITH BIOLOGIC FORMS OF STEM RUST. Diagrams 1, 2, 3, and 4 present summaries of inoculation experi- ments with Puccinia graminis tritici (stem rust) from wheat. Diacram |.—Summary of inoculation experiments with stem rust from wheat. 59 SS, aa 0 = So 66 1 =——F 30° W 52 58 zt B 68 B 60 B 20 28 16] 8 5 1 eg, 1 36 B sae Or IG R W Io St- fl. RS Sane 7 === 0 50’ 50 flecked. Ae 2 10 26]. 30 O ay Bf —-B — 31 Be 6) R 52’ 5D Bigait O85 O 60’ 60 St: fl. The results indicated in diagram 1 are further summarized in diagram 2, which shows only the successful infections: Diacram 2.—Summary of the successful inoculations shown in diagram 1. WwW. B B, ete WyR 8 ee oO. 1 Except in a few instances the grains used in these experiments were Preston wheat, Manchuria barley, Early Gothland oats, and spring rye, grown in Minnesota. 88550°—Bull. 216—11——2 18 THE RUSTS OF GRAINS IN THE UNITED STATES. The wheat stem rust was carried directly to wheat, rye, and barley, but not to oats.'. The figures show plainly that it goes with great ease to barley and wheat and very rarely (1 out of 32 inoculations) to rye. This rust can infect barley with about the same ease with which it goes to its own host. Although this may be interpreted as indicating the identity of barley and wheat stem rusts, it is not con- clusive, since the barley rust behaves differently from the wheat rust toward the same cereals. When the wheat rust is taken to barley and then transferred to the other cereal hosts, it is seen that the barley has a decided influence on the rust. Diagram 3 sum- marized from diagram 1 shows its effect. DiaGramM 3.—Summary of successful transfers of wheat rust through barley. 28 16 2 B i6 Om B Ww RS The wheat rust from barley infects the wheat and barley again with great ease, and the rye with greater ease than the direct infec- tion from wheat. Finally, from the second barley host the wheat rust may even infect oats, a result rarely obtained directly from wheat. In brief, the wheat rust, after passing on to barley, is capable of infecting all of the four cereals, but when transferred from the wheat without passing to barley, only barley and wheat are usually infected, rye being rarely infected and oats very rarely, indeed. Among the cereals, therefore, the stem rust of wheat in this country is not confined to wheat as closely as Eriksson has found it to be in Sweden, nor is it confined to barley and wheat, as found by Carleton. Diagram 4, summarized from diagram 1, shows the actual course of infection of wheat rust taken, in succession, on all of the small grains, Diacram 4.—Summary of successful inoculations of diagram 1, showing succession. 26 28 16 8 2 1 ORE bi W Bay Bap Big RG R= W7 Om The effect on the wheat-rust parasite when barley is taken as a host is clearly shown to be that of enabling a wider range of infection. An interesting feature of this diagram is seen in the fact that the final successful inoculation of oats was directly from the wheat, but the rust had previously passed on to three barley plants and two rye plants. Diagrams 5 to 10, inclusive, present summaries of inoculation experiments with Puccinia graminis hordei (stem rust) from barley. 1 Mr. H. B. Derr, of the United States Department of Agriculture, reports having obtained in the labora- tory the following successfulinoculations: W—>O ——>B ——>O ——>0O. The numberof successful infections in each case was not recorded. 216 ~ P De ee OeEeOOOOOeEeEeEOOEOEEEEeEeEeEeeEeEeEeEeEeEeEeeEeeeeeE eee Ts Te . ; LIFE HISTORIES OF RUSTS. 19 Diagram 5.—Summary of inoculation experiments with stem rust from barley. 32 B 38° : ‘ Bo’ 1 flecked. 4 7 O 35) 7 flecked. — ; O-: 9 5 0 Way' OF: 19 3 ee apels 0 B s Ri 3 9 27 B—|R 35 3 flecked. — 3 0 5 3 15 R coy 1 flecked.! O 25 B 9 Taare 8 1 01 R 4’ 3 flecked.— R Jo RB -g flecked a 3653 39 20 O a7’ 8 flecked. WwW Wa Se Vay Semed Lic 712 10 4 a Wig ae Was R 59 7 flecked. Wi SSS 1 5 R 55’ 6 flecked. O 377 5 flecked. 17 B 39° Diagram 6 summarizes the successful infections shown in dia- gram 5. DracGram 6.—Summary of successful inoculations shown in diagram §. B. O O V. B B R B O B Ww. SS R R. O WwW W W W R WwW R O. B. The barley rust is seen at a glance to be more versatile than wheat rust. All four cereals are directly infected by this rust, as shown by diagram 7. Dracram 7.—Summary of successful direct inoculations of stem rust of barley. B => 1 Eaten by slug. 216 20 THE RUSTS OF GRAINS IN THE UNITED STATES. The stem rust of barley, like that of wheat, goes with equal ease on barley and wheat. Rye is more easily infected by barley rust than by the wheat rust. Oats are capable of direct infection by barley rust. The oat pustules were very small and weak, and thus precluded the possibility of very numerous experiments with the barley rust from oats; but diagram 5 shows that successful infections were obtained as follows: Diacram 8.—Summary of successful inoculations of oats with stem rust of barley. if 1 a oF B -O The barley rust, after being transferred to rye, was carried to barley and then to all of the four cereals; it was likewise transferred to wheat and then to the other cereals. The rye and wheat rusts, as shown by other diagrams, are usually incapable of direct transfer in this manner. That the barley rust is carried through wheat and then transferred to the other cereals is shown in diagram 9 summarized from diagram 5: Diacram 9.—Summary of transfer of stem rust of barley through wheat to other cereals. 8/5 fo) = Nie NIS mw B+ The barley rust, then, after passing through rye and wheat, is still able to infect all four cereals. Diagram 10, summarized from diagram 5, shows that barley rust was successfully transferred to all of the four cereals. Diacram 10.—Summary of transfers of stem rust of barley directly to other cereals. 3 8 5 3 _ 15 B R35 Bo O 55 Bo Wiz The comparatively large percentages of infection obtained are probably accounted for by the fact that in each case barley inter- vened as a host between rye and oats and between oats and wheat. The barley stem rust enjoys the widest range of any of the biologic forms of the cereal rusts. On the other hand, a transfer of any of the other stem rusts to barley widens the range of that rust. We have here, then, a decided reaction of host upon parasite, enabling the latter to adapt itself to hosts not ordinarily congenial; for instance, w—>B SO; As shown under wheat rust, the barley rust and wheat rust are seen to be not necessarily identical, though the fact that they are 216 LIFE HISTORIES OF RUSTS. on but slightly changed forms of the same species can not be doubted. Although they infect barley and wheat plants with almost equal ease, they behave differently in the other inoculations. That this differ- ence may be attributed to the influence of host on the parasite is clear from the fact that wheat rust after passing to barley behaves in a similar manner to the barley rust, although the latter retains a more versatile character even after passing to the other host plants. Table II (p. 26) throws further light on the relationships of wheat and barley rusts. Diagrams 11 and 12 summarize the inoculation experiments with Puccinia graminis secalis (stem rust) from rye. DraGram 11.—Summary of inoculation experiments with stem rust from rye. 0 Oo 29° Ont W 31, 30 flecked. 17 R 55° R B Re Be 8 5 Si 1 oO py 23 31 T 7 Ws Ga 3 0 oS BT: B — 4 Re 7 4 = 18 3 mH ih al 20 R jo? jp flecked. 3 0 R 6 By 1 Ee 1 1 R: Ee EB 23 O >» B 3 ‘ 4 4 ® y9 R 5 3 ———_ R = The rye rust infects rye and barley with about equal ease; in fact, the proportion of successful inoculations indicates even greater preference for barley than for rye, though a much larger number of inoculations would be necessary to decide this point conclusively. Wheat is rarely directly infected. Derr reports having obtained the successful infection of rye rust to wheat in a few instances. These infections were not obtained directly, but 1 out of 22 inoculations was successful after the rye rust had passed to barley. In our own 216 22 THE RUSTS OF GRAINS IN THE UNITED STATES. experiments no infections to wheat after barley and only one to oats after barley were obtained with the rye rust, but only a small number of attempts on wheat and oats were made from the rust on barley. There is little doubt that rye rust can be made to go to wheat after passing to barley, as has been shown by Derr’s experiments previously cited. Diagram 13, summarized from diagram 11, shows the direct infections obtained with stem rust from rye. DracramM 13.—Summary of the direct inoculations of barley and rye with stem rust from rye. 17 R 25° R 23 B a Diagram 14 shows the possibility of infection of all four cereals by passing to barley. Diagram 14.—Summary of inoculations by stem rust of rye directly to two cereals and through barley to wheat and oats. B——-W (Derr). 17 R\B 25 23 1 Ba > ee ae Diagram 15 presents a summary of inoculation experiments with Puccinia graminis avenae (stem rust) from oats: | Diacram 15.—Summary of inoculation experiments with stem rust from oats. ee ae R 32° Diagram 16 presents a summary of the successful infectionst shown in diagram 15. Driacram 16.—Summary of successful inoculations shown in diagram 15. 87 oO 88° 7 1 84 Big B 1 Derr reports having obtained a direct infection of oats to wheat and one of oats torye. In the case of the wheat the rust was further transferred as follows: O——>W——>B——>W. He also further carried the oats to barley and transferred infection as follows: oO. a an oO 216 LIFE HISTORIES OF RUSTS. 2S The number of successful inoculations of stem rust of oats to wheat and rye has been insufficient to make absolute statements concerning them, but there is little doubt that under highly favorable conditions they can be made. On the other hand, there is no doubt that the oat rust can be carried to barley and from barley to either oats or barley, as a large number of successful trials by Derr have shown. In all cases the pustules obtained in the course of the inoculations were small and weak and the rust was very evidently not on a congenial host. The oat rust is thus seen to be the most closely specialized of the biologic forms of Puccinia graminis on the small grains, but in its ability to infect the other species under rarely occurring conditions still shows its close affinity to the other rusts. Of all the stem rusts on the small grains that of oats is the most distinctive and individualistic in appearance, having larger pustules of uredo spores which are formed very commonly both on stems and leaves (as in barley), in sharp contrast with the more restricted location of the pustules in the rusts of wheat and rye. As a biologic form, the stem rust of oats may be said to be generally confined to oats. It can at times be carried to barley, but never produces large or vigorous pustules. It is only rarely that the transfers to wheat and rye can be made. EXPERIMENTS WITH BIOLOGIC FORMS OF LEAF RUST. Fewer experiments have been made with the biologic forms of leaf rusts than with the stem rusts, but these experiments indicate that, as a rule, the leaf rusts are not as versatile as the stem rusts, being confined more closely to the original hosts. Diagram 17 presents a summary of inoculation experiments with Puccinia rubigo-vera tritici (leaf rust) from wheat. Dracram 17.—Summary of inoculation experiments with leaf rust from wheat. The leaf rust of wheat was carried directly to wheat, rye, and barley, but in 47 inoculations it would not transfer to oats. It is sinilar to Puccinia graminis tritici, which can easily be transferred to the first two cereals, to rye rarely, and to oats only in very excep- tional instances. But the leaf rust of wheat will not infect barley nea'ly as readily as the stem rust of wheat, but seems to transfer to rye more easily than the stem rust. No experiments were made 216 94 THE RUSTS OF GRAINS IN THE UNITED STATES. to determine whether or not this rust goes more easily to the other cereals after having been grown on barley, as is the case with the stem rust of wheat. Carleton (30, p. 20) reports negative results with Puccinia rubigo-vera tritici in inoculations on oats, barley, and rye. This indicates either that the strain of rust which he used for his inoculations may have been slightly different from the strains used in our inoculations, or that the conditions were not as favorable for infection. Such a difference in strains, perhaps, may exist in the same species of rust gathered from different localities even in the same country. Diagram 18 presents a summary of inoculation experiments with Puccinia simplex (leaf rust) from barley. DriaGRAM 18. Summary of inoculation experiments with leaf rust from barley. These experiments indicate that the leaf rust of barley is closely confined to the one host, barley, as no infection took place on either wheat, rye, or oats in a large number of inoculations on each. In this particular it is very different from the stem rust of barley, which may be transferred to the other three cereals. Diagram 19 presents a summary of inoculation experiments with Puccinia rubigo-vera secalis (leaf rust) from rye. DraGraM 19.—Summary of inoculation experiments with leaf rust from rye. 0 Wa (most leaves flecked). 33 Raz 0 B 50 (many leaves flecked 0 O—- eB The leaf rust of rye is also highly specialized and in numerous inoculations did not transfer to the other cereals. Carleton’s results (30, p. 43) in numerous trials are identical. The flecking of the wheat and barley showed that they were infected with the rust, buf that extensive development of the rust mycelium did not take place The rye stem rust, on the other hand, easily transfers from rye t) barley. Diagram 20 presents a summary of inoculation experiments wth Puccinia coronata (leaf rust) from oats. 216 —— sO LIFE HISTORIES OF RUSTS. A5 Diacram 20.—Summary of inoculation experiments with leaf rust from oats. 0 Wi (several leaves flecked). 0 R B (several leaves strongly flecked). Sar 47 44 Pre 7 B sa Although highly specialized, the leaf rust of oats can be transferred to barley, but it did not transfer to either wheat or rye. The effect of barley on it was not determined, except to show that from barley to oats the rust in a few trials transferred as easily as from oats to oats. In Carleton’s experiments (30, p. 46) inoculation with this rust on barley gave negative results, In many of the experiments on biologic forms previously cited, it was noticeable that the same rust species would not give the same percentage of infection on various hosts if the inoculations were made from rusts gathered in different localities. This may account for the diverse results of different investigators and leads to the belief that there may be a large number of strains of a rust species, none of which will act exactly like another toward the same hosts. Undoubtedly by variation and adaptation to varying conditions a certain rust species, widely distributed, may form a large number of strains or types which, when this process has been continued for a considerable time, differ widely in their physiological reactions. These may become the physiological or ‘‘biologic”’ species. EFFECT OF CHANGE OF HOST ON THE MORPHOLOGY OF THE UREDOSPORE. In experimental cultivation of Puccinia graminis tritici from wheat on barley and Puccinia graminis hordei from barley on wheat it was found that there existed a slight morphological difference between the uredospores of the stem rust of barley and the stem rust of wheat. Upon closer examination this difference seemed to be meas- urable—that is, the uredospores of barley measured (on a basis of measurement of 50 spores, widely selected) considerably shorter and very slightly narrower than those on wheat. An experiment was therefore inaugurated to determine what the effect would be on the size of the spores of the barley rust when grown on wheat and of the wheat rust when grown on barley. Transfers were accordingly made of the barley rust to two pots of wheat and of the wheat rust to two pots of barley. The barley rust on wheat was then transferred to wheat plants continuously for about a year, and the wheat rust in a similar manner was grown on barley. The rust in each pair of pots _was transferred to two other pots, so that two separate strains were 216 26 THE RUSTS OF GRAINS IN THE UNITED STATES. kept continuously for check purposes. All precautions possible to ordinary greenhouse work were taken to avoid accidental infection and the mixing of cultures. The results given in the table below show the measurements of (1) the original material—that is, of barley rust on barley and wheat rust on wheat; (2) the same rusts after 6 inoculations had been made on newhosts; and (3) after 17 inoculations, covering a period of almost one year. The spore measurements were carefully made from typical spores. Where 50 spores were measured, they were taken from at least 5 different pustules and from 2 or 3 leaves. Where 10 were used they were selected from normal, mature pustules. The difference in size between spores from mature and immature pustules is quite marked, the immature being smaller than the mature. As the variation in width of the spores from different hosts is very slight, measurements of 10 may show a small difference from the measurement of 10 original spores toward either plus or minus. Tasie Il-—Change in morphology of the uredospores by cultivation of stem rust from wheat on barley and from barley on wheat. z 8 3 Spore measurements (). ~ Los | = = _ Ss | 4 |Spore meas-| & Zee z tremens “4 z Difference = | original ma-| 3 ., Cultiv (compared n | P > 2 n ‘ultivated : A Decarinti Date of | $ terial (x). | So | Dateof| & material. | With orig- escription of culture. | collection! ¢ = loollaction | 2 inal ma- ‘of spores.| > | 4 ca “| Be terial) S oF r=) 5 . Seas S : 2) geloe le 4 |-3 ae a/2)¢ 8 | 2) 8 Sate Z\|EF | A |e Z| EE | 1906. | | 1907. Wheat rust transferred | Nov. 13 | i nd to and grown continu- and | 50) 18.15 31.33{ if een oe y eae 0.1 0 ee ously on barley. ------ rk NOR: 14, Ini erg a (ee =. See Barley rust transferred |) Nov. 14 } } | | to and grown continu- and 50) 17. 46, 28.51{ ie xed = a 7 rere e get ously on wheat......... Nov. 22 | | | Save | - c | ; : This table shows that in the original material the wheat-rust uredospores are 0.69 » wider and 2.82 » longer than the corresponding barley-rust spores. As stated above, the difference in width is too small (a little more than 0.5 ) to allow of safe conclusions as to its variations. After 6 successive infections of each rust on the other host, the wheat rust had lost an average of 1.2 » in length, the width remaining practically the same (+0.02 »). The barley rust, on the other hand, had gained in length 1.71 y», the width running practi- cally the same (+0.07 »). The two rusts at this time gave almost identical measurements, viz, wheat rust on barley 18.17 » by 30.13 4 and barley rust on wheat 17.53 « by 30.22 ». After 17 successive intervening inoculations (almost a year from the time of the collection 216 EEE — LIFE HISTORIES OF RUSTS. aT of the original material) the wheat rust on barley had lost from the original material 0.63 ~ in width (practically negligible) and 2.32 p in length, while the barley rust on wheat had gained 0.21 » in width (again practically negligible) and 2.61 » in length. If these measure- ments are compared with those of the original material it will be seen that the wheat rust on barley has decreased in spore size to almost exactly that of the original barley rust and the barley rust on wheat has increased in spore size to nearly that of the original rust on wheat, as follows: Original wheat rust.............. a eewasr a a 18: Lo pe by Si. 3a tt. Barley rust after 10 months on wheat. hide pea eee 17°67 ye by SL 12 Preeitte WAnOY CUS 222. s- fs oe gases 235s 17. 46 » by 28. 51 p. Wheat rust after 10 months on barley............... 17. 52 p by 29. 01 p. Although these differences are not great, they seem sufficient to indicate that the host plant exercises not only a decided physio- logical and biological reaction upon the parasite but that it may, even in such a short period as one year, exert a measureable effect on the morphology.’ It has already been shown (p. 17) that wheat rust if first transferred to barley may be transferred to oats with considerable ease, thus showing the physiologic change going band in hand with the morphologic change. GENERAL SUMMARY OF CONCLUSIONS DERIVED FROM EXPERIMENTS ON BIOLOGIC FORMS. In summarizing, the following points in regard to biologic forms of rusts of cereals may be emphasized: (1) Puccinia graminis tritici Erikss. and Henn. (stem rust of wheat), P. graminis hordei F. and J. (stem rust of barley), P. graminis secalis Erikss. and Henn. (stem rust of rye), and P. graminis avenae Erikss. and Henn. (stem rust of oats) are undoubtedly biologic forms of the same species Puccinia graminis Pers. (2) These forms are not entirely confined to their respective hosts, but vary in range in part according to the host plants they have been recently inhabiting. (3) P.rubigo-vera tritict Carleton (leaf rust of wheat) and P.rubigo-vera secalis Carle- ton (leaf rust of rye) are more highly specialized than the corresponding stem rusts. (4) P. graminis hordei (stem rust of barley) has ordinarily the widest range, while Puccinia simplex Erikss. and Henn. (leaf rust of barley) and P. rubigo-vera secalis (leaf rust of rye) have more restricted ranges. (5) Under very favorable conditions, particularly after first transferring to barley, all the stem rusts can be carried successfully to the other cereals. _ (6) When the rusts are transferred to uncongenial hosts and produce pustules on these, the pustules are almost invariably minute and weak, producing com- paratively few spores. Some pustules apparently never open. The con- genial hosts of each rust may be summarized as follows: P. graminis tritici (stem rust of wheat) on wheat and barley. 1 Evans (50, p. 461) has shown previously that many of the biologic forms of the genus Puccinia can be distinguished by slight differences in morphology of the early uredo mycelium, particularly in the forma- tion of the substomatal vesicle, 216 28 THE RUSTS OF GRAINS IN THE UNITED STATES. . graminis hordei (stem rust of barley) on barley, wheat, and rye. . graminis secalis (stem rust of rye) on rye and barley. . graminis avenae (stem rust of oats) on oats. . rubigo-vera tritici (leaf rust of wheat) on wheat. . simplex (leaf rust of barley) on barley. . rubigo-vera secalis (leaf rust of rye) on rye. . coronata (leaf rust of oats) on oats. (7) Two biologic forms may inhabit the same cereal or cereals (for instance, wheat and barley rusts on wheat and barley) without being identical. (8) By gradual variation and adaptation to varying conditions a certain rust spe- cies, widely distributed, may form a number of strains or types, differing in physiological reactions. (9) The host plants exercise a strong influence, not only on the physiological and biological relationships, but in some cases even on the morphology of the uredospores. In regard to the relationships of the cereal rust forms to the numer- ous grass rusts of the United States there is much to be done. A beginning has been made, and experiments have been performed confirming Carleton’s results (30, pp. 55, 61-63) in regard to the infec- tion of Hordeum jubatum with the stem rusts of wheat and barley and orchard grass with the stem rust of oats. That Agropyron repens also acts as host for the stem rust of wheat has been proved. The relationship of Puccinia phlei-pratensis to other rusts has been inves- tigated and a summary of results published (59, p. 791). The importance of this phase of the biologic forms of cereal rusts is very great and demands early attention. The most extensive results obtained up to the present time are those of Carleton with the American and Eriksson with the European rusts.! hey hg Se. te THE ACIDIAL STAGE OF RUSTS. HISTORY OF BARBERRIES IN RELATION TO RUST. Up to 1864-65, when De Bary demonstrated the hetercecism of Puccinia graminis Pers., rust life histories were very incompletely 1 During the course of preparation of this bulletin several important papers have appeared throwing further light on biologic forms of rust. J. C. Arthur (‘Cultures of Uredinez in 1909,’’ Mycologia, vol. 2, no. 5, 1910, pp. 227, 228) cites experiments of his own showing that Puccinia poculiformis (Jacq.) Wettst. (P. graminis Pers.) has been grown on Triticum vulgare from zcidiospores derived from inoculations on Berberis vulgaris with teleutospores from Agropyron repens, A. tenerum, A. pseudorepens, Agrostis alba, Cinna arundinacea; Elymus canandensis, and Sitanion longifolium, respectively. He concludes that ‘although in the uredinial stage this rust shows racial strains that inhibit the ready transfer from one species of host toanother * * * yet in the «cial stage racial strains play no part, and the barberry acts as a bridging host between each and every other gramineous host.” Jaczewski, on the other hand, in a recent article (Zeitschrift fiir Pflanzenkrankheiten, vol. 20, no. 6, 1910, pp. 356, 357) cites comprehensive inoculation experiments to show that the stem rusts of grains and grasses in Russia as a rule are not interchangeable even with the barberry as a bridging host, but retain distinct physiological specialization in the ecidial as well as in the uredo stage. He also shows that the* eecidia produced from inoculations with the teleutospores from the stem rusts of wheat and barley, respec tively, behave differently when used for inoculation on the same series of grains and grasses, and he believes it easily possible that the stem rust on barley is a distinct physiological species, a conclusion independently derived in another way by the writers of this bulletin (pp. 17-20 and 25-27). Although it is evident from the experiments cited by Arthur that the barberry may act as a bridging host for rusts between some gramineous hosts, in the light of the work of Jaczewski and others it seems that further experimentation on a large number of rusts is necessary before the sweeping statement that “‘in the ecial stage racial strains play no part” can be generally accepted. 216 — THE XCIDIAL STAGE OF RUSTS. 29 understood. That the proximity of barberries to grainfields was injurious to the crops had long been believed, although no one could say just what caused the damage. In many cases stringent laws making the destruction of barberries compulsory had been enacted. Klebahn (63, p. 205) finds the first mention of such legislation by De Magneville (68, p. 18), who says that laws against the growing of barberries were extant in Rouen, France, in 1660. The citations of Loverdo (67, p. 199) and Prillieux (86, p. 221) undoubtedly are taken from this reference. Klebahn, however, was unable to locate the original law, even though M. Ch. de Beaurepaire, Archiviste Paleographe de la Prefecture de la Seine Inferieure in Rouen, looked through the record of laws for 1660 and also for 1760. There is, thus, some doubt about this report. In the eighteenth century rust literature became much more extensive. According to Klebahn (63, pp. 205, 206), Erhart (38, p. 59) says that in 1720 an English farmer destroyed his neighbor’s barberries with hot water because they hurt his wheat. This mstance is also cited by Hornemann (56, p. 8). De Bary (12, p. 35) found the noxiousness (Schidlichkeit) of barberry to wheat mentioned by Kriinitz (65, p. 198), who says: Man hat sie ohne Grund beschuldigt, dass sie in den nahe dabei stehenden Korn den Brand verursachten, weswegen dieselben sogar aus den Zaiinen um die Landgiiter verbannt werden. Withering (105, p. 199) in 1776 wrote: This shrub should never be permitted to grow in corn lands, for the ears of wheat that grow near it never fill, and its influence in this respect has been known to extend as far as 300 or 400 yards across a field. According to Davis (37, p. 82) the oldest legislation in the United States concerning barberries was enacted in Connecticut in 1726, when towns were empowered to pass regulations at their town meet- ings for the destruction of barberries within their respective town- ships, “‘it being by plentiful experience found that where they are in large quantities they do occasion, or at least increase, the blast on all sorts of English grain.” In Massachusetts an act was passed in 1755 making the destruction of barberries in that Colony before June 13, 1760, compulsory (73, pp. 797, 798) because ‘it has been found by experience that the blasting of wheat and other English grain is often occasioned by barberry bushes to the great loss and damage of the inhabitants of this province.”’ Similar laws, but much less stringent than those of Massachusetts, were passed in Rhode Island in 1766 and 1772, and again in Connecticut in 1779. In 1781-1784 Marshall (71, pp. 19, 359; 72, p.11), by reason of the strong existing prejudice against barberries in England, undertook actual experiments to determine whether or not barberries were the 216 30 1HE RUSTS OF GRAINS IN THE UNITED STATES. cause of rust in grain. In February, 1782, he planted a barberry bush in the middle of a wheat field. He states that a little before harvest: The wheat was changing and the rest of the piece (about 20 acres) had acquired a considerable degree of whiteness (white wheat), while about the barberry bush there appeared a long but somewhat oval-shaped stripe of a dark, livid color, obvious to a person riding on the roadside at a considerable distance. Marshall continues as follows: The part affected resembled the tail of a comet, the bush itself representing the nucleus, on one side of which the sensible effect reached about 20 yards, the tail pointing toward the southwest, so that probably the effect took place during a northeast wind. At harvest, the ears near the bush stood erect, handling soft and chaffy; the grains slender, shriveled, and light. As the distance from the bush increased the effect was less discernible, until it vanished imperceptibly. The rest of the piece was a tolerable crop and the straw clean, except on a part which was lodged, where the straw nearly resembled that about the barberry; but the grain on that part, though lodged, was much heavier than it was on this, where the crop stood erect. The grain of the crop, in general, was thin bodied; nevertheless, 10 grains, chosen impartially out of the ordinary corn of the piece, took 24 of the barberried grains, chosen equally impartially, to balance them. This experiment was repeated by Marshall in Staffordshire with similar results, and he became more firmly than ever of the opinion that barberry was injurious to wheat. In 1787 Withering (106, p. 366) in speaking of Berberis vulgaris repeated the statement which he made in 1776, already quoted (p. 29). According to Windt (104), Schépf (93, p. 56) in 1788 said that in America the barberries in proximity to fields were blamed for injuring grains and other field crops. Just how the injury was caused no one could say. A severe epidemic of “mildew” took place in England in 1804 (84, p. 51). Arthur Young, secretary of the board of agriculture at that time, issued a circular asking for information as to the cause of ‘‘mildew”’ in wheat. In answer to the question “Have you made any observations on the barberry as locally affecting wheat?” numerous correspondents reported that injury resulted wherever barberries occurred near a wheat field. According to the same authority, Sir Joseph Banks (14, p. 521) in 1805 said: “Is it not more than possible that the parasitic fungus of the barberry and that of wheat are one and the same species, and that the seed is transferred from the barberry to the corn ?” In 1806 Windt (104, p. 8), from his own observations and experi- ments, came to the conclusion that the barberry was the cause of rust in wheat and that it acted as a center of infection. 216 ee THE ZCIDIAL STAGE OF RUSTS. ow Thomas A. Knight, president of the Royal Horticultural Society of London, in 1813 recognized the importance both of the uredo stage and of the barberry. He says (64, p. 85): A single acre of mildewed wheat would probably afford seeds sufficient to com- municate disease to every acre of wheat in the British Empire, under circumstances favorable to the growth of the fungus. Knight adds: There is also reason to believe that the barberry tree communicates this disease to wheat, and I have also often noticed a similar apparent parasitical fungus upon the straws of the couch-grass in the hedges of cornfields. In 1818 a paper was published by the Royal Agricultural Society of Denmark, which was the result of investigations by Schoeler (92, p. 289) in Denmark from 1807 to 1816. He had planted grains around barberries and found that rye and oats were liable to be destroyed every year by rust; that when large and small barberry bushes were planted in his field— The larger bushes did not give rise to rust when they lost their foliage in the process of transplanting, but, on the contrary, the smaller bushes, which did not lose their leaves so readily, did give rise to the rust in rye to a very marked degree. In 1816 Schoeler actually cut freshly rusted barberry leaves, carried them in a box into a rye field, and rubbed them on rye plants moist with dew. The plants were carefully marked and in five days were found to be severely affected with rust, ‘while at the same time not one rusty plant could be found anywhere else in the field.” A German farmer performed similar experiments in 1818 (77, p- 280; 52, p. 408). He gathered the dust (Staube) which fellfrom the cup (Kapsel) on barberry leaves as he shook them and placed it on rye plants far from the rye fields and where there were no barberries in the neighborhood. After five or six days the plants thus treated were attacked by rust, while there was nothing similar on any other plants. He concluded that the dust from barberries blown by the wind to grains causes the rust. While many botanists still believed that the rusts on barberry and wheat belonged to different genera, some were sufficiently good observers to believe that the Puccinia and Uredo were in some way connected. In 1852 Tulasne (97, pp. 79-113) proved the genetic relation between the summer rust (Uredo) and the autumn rust (Puccinia) and also showed (97, p. 141) that the autumn spores of many of the rust species, among which are Puccinia graminis and P. coronata, go through a resting period from autumn until spring before they will germinate. It remained for De Bary, in 1864-65, to publish the results of his experiments, which actually proved heterecism of Puccinia graminis (12, pp. 15-49). He demonstrated in 1864 that the sporidia from 216 32 THE RUSTS OF GRAINS IN THE UNITED STATES. teleutospores from Agropyron repens Beauv. and Poa pratensis L. would give rise to the ecidia on Berberis and, in 1865, that scidio- spores from Berberis sown on rye would produce uredospores and later teleutospores. He did not stop here, but kept at work on other rusts, and in 1865 showed that Puccinia coronata has its ecidium on Rhamnus frangula and P. rubigo-vera its ecidium on Lycopsis arvensis. From this time on, life-history work on the Uredinez has made rapid strides and the connection of one ecidial form after the other has been discovered by such men as Oersted, Fuckel, Magnus, Schréter, Wolff, Rostrup, Winter, Nielsen, Reichardt, Hartig, Rathway, Cornu, Plowright, Farlow, Barclay, Thaxter, Eriksson, Klebahn, Arthur, Holway, Kellerman, and others.’ In 1884 Plowright produced successful infection on Berberis with rust from teleutospore material from Series sat from Minneapolis, Minn., to Washington, D. C., October 8, 1907. 10 Several. 1 Series sent from Washington, D. C., to Minneapolis, Minn., March 19, 1908. 12 Failure due to extreme heat in greenhouse. 13 Five leaves pustuled with Puccinia coronata, accidental infection. Failure of Puccinia graminis due to extreme heat in greenhouse. 14 Inoculated from EE. 15 Not recorded. 16 Inoculated from gg. 17 Experiment discontinued. 216 THE ACIDIAL STAGE OF RUSTS. Srl Tasie IIl.—Summary of experiments to determine the vitality of successive uredo genera- tions of various grain rusts—Continued. PUCCINIA GRAMINIS HORDEI ON BARLEY. Capital letter series. Lower-case letter series. Number Number r Series Date ee of leaves | Date Nous Series ek of leaves| Date Ruaiber letter. ey te “| inocu- | matured. tuled. | letter. fon inocu- | matured. | ° t ee ion. intede pustuled. E iveds pustuled. 1907 1907 1907 10 | Feb. 19 Ui hel eee Feb. 6 10 | Feb. 19 8 10 | Mar. 5 107} Deze Feb. 19 10 | Mar. 5 8 10 | Mar. 25 TONING aa aes Mar. 5 10 | Mar. 25 10 7 | Apr. 4 (oy) |G Eee Mar. 25 10} Apr. 4 10 310 | May 7 lid] Bases aS Apr. 17 7| May 7 8 10 | May 25 OQ) izececc sce May 7 10 | May 25 10 8 | June 13 MeO Wi Plo e eas May 26 8 | June 13 44-5 10 | June 25 4+5 | h. June 14 10 | June 25 4+5 10 | July 9 SO iteoes 2 = June 26 9| July 9 68 5 | July 21 Ss diseeee cae July 10 9} July 21 7 10} Aug. 6 10| k .| July 22 10 | Aug. 6 10 10 | Aug. 21 LOM eee SS: Aug. 7 10 | Aug. 21 10 10 | Sept. 8 POM prs ee Aug. 22 10 | Sept. 8 10 10 | Sept. 25 10}n Sept. 9 10 | Sept. 25 10 10 | Oct. 8 (8) o7 Sept. 26 10 | Oct. 8 (8) 11 | Nov. 8 Alpes: Oct. 16 9} Oct. 29 9 10 | Nov. 20 10} q -| Oct. 31 7 | Nov. 18 7 9 | Dec. 10 Sule t ase Nov. 20 9 | Dec. 10 8 1908. 1908 10 | Jan. 10%} Stee sora Dec. 12 10 | Jan. 7 10 1908. 10 | Jan. 25 SO Mies ee Jan. 7 10 | Jan. 25 1010 10 | Feb. 15 108 | u... -| Jan. 25 10 | Feb. 15 9 10 | Mar. 3 LOR | evees -| Feb. 15 10 | Mar. 3 10 10 | Mar. 19 TON will Sere Mar. 3 10 | Mar. 19 10 10 | Apr. 13 di] eke oee MAT. a 27, 10 | Apr. 13 6 10 | Apr. 28 Bn Wsses coe a PApE. 13, 10 | Apr. 28 3 10 | May 13 HOBIEZ ea ence Apr. 28 10 | May 13 5 10 | May 26 8 | aa.......| May 13 6 | May 26 5 10 | June 12 tale) 2) sere May 26 10 | June 12 5 10 | July 10 i Oa | keche a June 18 10 | July 10 1 dd =e: July 10 7 | July 28 3 Cot eeee July 28 7 | Aug. 12 1 ff Aug. 12 10 | Sept. 1 8 gg... Sept. 1 10 | Sept. 17 (8) 320 3 eee Sept. 17 10 |} Oct. 2 18:10! } bhi. - =.= Sept. 17 10) | FOcte we 8 (0) eee Oct 2 10 | Oct. 22 1G) | es. Oct. 2 10 | Oct. 22 10 ee Oct. 22 10 | Nov. 6 LOE eijsees Oct. 22 10 | Nov. 6 10 ee Nov. 6 10 | Nov. 20 TOM ako sere Nov. 6 10 | Nov. 20 10 1.) ees Noy. 20 10 | Dec. 12 Sap aie Nov. 20 10 | Dec. 12 8 1909. 1909 10. [eee Dec. 12 10! Jan. 10 i) |) tbe oe Dec. 12 8 | Jan. 10 5 1909. 1909 ININese dan: 10 5.| Heb: 7 1 Jan. 10 10 | Feb. 7 3 OO... = Feb. 22 5 | Mar. 14 3 Feb. 22 6 | Mar. 14 2 1 oe Mar. 14 10 | Mar. 30 10 Mar. 14 10 | Mar. 30 10 QQ). seas Mar. 30 10 | Apr. 12 9 Mar. 30 10 | Apr. 14 6 igile ae Apr. 12 10 | Apr. 27 10 Apr. 12 10 | Apr. 27 10 SS... Apr. 27 10 | May 20 i Apr. 27 4| May 20 4 Becca ciate May 20 8 | June 14 7 May 20 10 | June 14 9 LOO June 14 10 | June 26 8 June 14 10 | June 26 8 A eee June 26 10} July 7 10 June 26 10 | July 7 10 WAN -2: July 7 10 | July 21 7 July 7 10 | July 21 10 BROS sare July 21 10 | Aug. 2 10 July 21 10 | Aug. 2 10 BYaY. Aug. 2 10 (14) (14) Aug. 2 10 (14) (14) 1 Pustules vigorous. 2 Series sent from Washington, D. C., to Minneapolis, Minn., April 8, 1907. 3 Three inoculations were made from material from dried leaves, 7 from fresh material shipped in pots 4 Plus sign signifies ‘“‘more than;”’ i. e., exact number of leaves pustuled not noted. 5 Slugs destroyed 8 plants. 6 Slugs destroyed 1 plant. ee ee from Minneapolis, Minn., to Washington, D. C., October 8, 1907. everal. 9 Pustules not as vigorous as usual. 10 Pustules not vigorous. ll Series transferred from Washington, D. C., to Minneapolis, Minn., March 19, 1908. 12 Failure due to extreme heat in greenhouse. 13 Inoculated from gg. 14 Experiment discontinued. 216 38 THE RUSTS OF GRAINS IN THE UNITED STATES. Tape III.—Summary of experiments to determine the vitality of successive uredo genera-— tions of various grain rusts—Continued. PUCCINIA GRAMINIS SECALIS ON RYE. Capital letter series. Lower-case letter series. | | Number Number ean Patent | of leaves arse 5 od eg ecg bight ad of leaves Date ec! etter. : | inocu- matured. etter | ma. i & tion. lated: pustuled tion. ee matured | 1907. | 1907. 1907. 1907. Red eat Feb. 6 10 | Feb. 19 OF id | Sere Feb. 6 10 | Feb. 19 4 Bre Feb. 19 10 | Mar. 5 A: Bt eee Feb. 19 10 | Mar. 5 4 ah ee Mar. 5 10 | Mar. 25 Bi Gees Mar. 5 10 | Mar. 25 5 1D eee Apr. 4 4| Apr. 8 a Soe Mar. 25 5 | Apr. 8 3 Mee enee Apr. 17 10 | May 7 4:0 622) 238 Apr. 17 3g ay 7 py x. -| May 8 6 | May 26 (4) | toceece os | May 8 10 | May 26 Lio -| May 27 5 | June 13 (4) pe ee See | May 27 6 | June 13 4 13 peeked June 14 4| June 26 A 110) Ip) cs eee a June 14 9 | June 26 60 | 1909. 1909. | 1909. 1909. AAS 2 July 7 10 | July 21 10 | aas...... July 7 10 | July 21 10 BiB ae eNe =e July 21 10} Aug. 2 S83) ‘ppzes>-2 | July 21 10°} Aug. 2 8 CC.. Aug. 2 103). eee seo (7) ee Z Aug. 2 10:| 32 seeee (7) Be) 110 Peet) 18 . 21 (4) Bats 7 7 i, 28 945 13 945 2 26 9+5 i 9 3 | j 23 10 Kear aes | July 24 10| Aug. 8| OF 7 | ese July 24 10; Aug. 8 10 Le | Aug. 9 8 |-Aug. 21 OME ee Aug. 9 10 | Aug. 21 0 Leste ee Aug. 22 116 Sept. 10 ig | eee Aug. 22 16 Sept. 10 5 Mins Be ee Sept. 11 5 | Sept. 27 iy ie sees Sept. 11 9 | Sept. 27 9 N ®.......| Sept. 28 9} Oct. 8 (4) ip Joe ee Sept. 28 10 | Oct. 8 (4) Oe Ses: Oct. 24 8| Nov. 8 3S | hOzsoseeee Oct. 16 8 | Oct. 29 8 1 ees ee Nov. 9 7 | Nov. 20 tps Oct. 31 10 | Nov. 18 10 (A) aa aae Nov. 20 9| Dec. 10 i re ee ee Nov. 20 10 | Dee. 10 10 1908. ™ 1908. life oe Dec. 12 10} Jan. 7 10 10} Jan. 7 10 } 1908. ee eee ee LEU Fi 10 | Jan. 25 10 10 | Jan. 25 10 1 eee Jan. 25 10 Feb. 15 10. 10 | Feb. 15 10 Waser Feb. 15 10| Mar. 3 10 | 10| Mar. 3 10 iVgls ee eee | Mar. 3 10 | Mar. 19 10 10 | Mar. 19 10 Wikeeeaees Mar. 30 10 | Apr. 13 10 10 | Apr. 13 10 XS ene Apr. 13 10} Apr. 28 7 10 | Apr. 28 10 Wee se Apr. 28 10 | May 13 10 10 ay 13 10 Ti Sea May 13 10 | May 26 10 | 10 | May 26 10 ASAE May 26 10 | June 12 10 10 June 12 10 IB Bao June 12 10 | June 25 10 10 | June 25 10 COS = June 25 10| July 10 10 7) July 10 7 1D Bae Sel July 10 10 | July 28 8 10 | July 28 10 1D Dees | July 28 6} Aug. 12 2 10 | Aug. 12 5 al ae | Aug. 12 5 | Sept. 1 1 10 | Sept. 1 7 CG Sept. 1 3 Sept. 17 (4) 9 | Sept. 17 (4) 1 Pustules vigorous. 2 Series sent from Washington, D. C., to Minneapolis, 3 Inoculations made from material from dried leaves. 4 Several. 5 Very hot when inoculations were made, hence no infection. 6 Not successive to preceding inoculations: material obtained directly from the field. 7 Failure due to extreme heat in greenhouse. 8 Material from D destroyed in transit. 9 Plus sign signifies ‘‘more than;” i. e., exact number of leaves pustuled not noted. 10 Inoculations made from i 11 Tnoculations made from K and k. 12 Series sent from Minneapolis, Minn., to Washington, D. C., October 8, 1907. 13 Series sent from Washington, D. C., to Minneapolis, Minn., March 19, 1908. 14 Letters HH and hh were omitted in the series. Minn., April 8, 1907. 216 THE ACIDIAL STAGE OF RUSTS. 39 Taste III.—Swmmary of experiments to determine the vitality of successive uredo genera- tions of various grain rusts—Continued. PUCCINIA RUBIGO-VERA TRITICI ON WHEAT—Continued. Capital letter series. | Lower-case letter series. Number = Number Series | Pate of | orieaves| Date | Number | series | Dateof | ofleaves| Date | Number letter Lae inocu- | matured. of eae letter. cule inocu- | matured.| Of leaves ‘ lated. | pustuled. lon. lated. pustuled. 1908. 1908. 1908. 1908. Mies «352 Sept. 17 Sr Octs (2 8 | ai--.=----| Sept. 17 10} Oct. 2 10 cee eee Oct. 2 10 | Oct. 22 AOn ye 2. Oct. 2 10] Oct. 22 10 inc aa Oct. 22 10 | Nov. 6 OU kes oss Oct. 22 10} Nov. 6 8 Lee Nov. 6 10 | Nov. 20 IO: Mees 2322 Nov. 6 10 | Nov. 20 10 WEM Ds i 52 Nov. 20 9| Dee. 12 9) | mm: ==. Nov. 20 10 | Dee. 12 10 1909. 1909. ININ= = 2-2: -|"Dee. 12 10 | Jan. 10 TOWN OMe Dec. 12 10 | Jan. 10 7 1909. 1909. Oe ee Jan. 10 10} Feb. 7 Sil OOzee ease - Jan. 10 10} Feb. 7 2 Ree 3 Feb. 7 7| Feb. 23 (iN id Mesecce Feb. 7 5| Feb. 23 5 OOr te Feb. 23 10 | Mar. 14 10) qqu-cee Feb. 23 10 | Mar. 14 10 FOR 522 Mar. 14 10 Mar. 30 10) bree acs. Mar. 14 10 | Mar. 30 10 Deeseas is Mar. 30 10 | Apr. 12 (O\) SSiesecsas Mar. 30 10 | Apr. 12 1 Ai ere Apr. 12 10 | Apr. 27 2 theses eee Apr. 12 10 | Apr. 27 2 UUiz<- Apr. 27 3 | May 20 Sh SU oes Apr. 27 5 | May 20 5 Wass -1.5 May 20 10 | June 14 LON evivioe sone May 20 10 | June 14 9 WAW = .3-.- June 14 8 | June 26 NU ee eee June 14 10 | June 26 9 1 eee June 26 10| July 7 {fal hoo ene June 26 10| July 7 10 Yoo July 7 10 | July 21 SieyiViece ces July 7 10 | July 21 10 LY Seta a8 July 31 10 | Aug. 2 10) az sce sae July 21 10} Aug. 2 10 AAR 52. Aug. 2 10 (1) (@) aaa......| Aug. 2 10 (4) (1) PUCCINIA SIMPLEX ON BARLEY. 1907. 1907. 1907. 10 | Feb. 19 10: aces sees Feb. 6 10 | Feb. 19 10 10; Mar. 5 10) pbe2= Feb. 19 10} Mar. 5 10 10 | Mar. 26 (?) Chee | Mar. 5 10 | Mar. 26 (7) 10| Apr. 4 UV) ato Ey | Mar. 26 10} Apr. 4 8 |e Maye ei TNC ee es Apr. 17 49] May 7 i 10 | May 28 10: ite eee May 8 10 | May 28 10 10 | June 13 1 | eae eee May 29 10 | June 13 10 10 | June 25 100 he June 14 10 | June 25 (2) 10} July 8 SOM e June 26 10 | July 8 10 10 | July 23 10) |ji 2-3-2 July 10 10 | July 23 10 10 | Aug. 7 LON kes July 24 10 | Aug. 7 10 S 10 | Aug. 23 10 le eee Aug. 9 10 | Aug. 23 10 s 10 | Sept. 8 OF ane ee Aug. 24 10 | Sept. 8 10 ONS 5 cd onc: | Sept. 9 10 Sept. 27 a (janie Sept. 9 10 | Sept. 27 10 OBL ee | Sept. 28 10 | Oct. 8 (2) Osen see Sept. 28 10 | Oct. 8 (°) pe. Oct. 24 10 | Nov. 8 TA Decar-ee Oct. 16 10 | Oct. 29 10 Oe Nov. 9 9 | Nov. 18 9) Ga Oct. 31 10 | Nov. 18 10 1 RAs a > Nov. 20 10 Dee. 10 10D ha eee ee Nov. 20 10 | Dee. 10 10 1908. 1908. Se ess sae Dee. 12 10 | Jan. 7 10) | (Seete sere Dec. 1 10} Jan. 7 10 1908. 1908. ee Jan. 7 10 | Jan. 25 TON ieee ee Jan. 7 10 | Jan. 25 10 ie aes dar. 25 10 | Feb. 15 LOM UISeES Jan. 25 10 | Feb. 15 10 Ve eee Reb. 15 10 | Mar. 3 LOS hayes Feb. 15 10 | Mar. 3 10 WSs Mar. 3 10 | Mar. 19 10: | (wis: .2:-< Mar. 3 10 | Mar. 19 10 Me) Se Mar. 30 10 | Apr. 13 10) exees Apr. 2 10 | Apr. 13 10 We. 2oeo.- Apr. 13 10 | Apr. 28 LOW Ayes Apr. 13 8 | Apr. 28 8 LA ee Apr. 28 10 | May 13 0) A/S eee Apr. 28 10 | May 13 10 PATA Seton | May 13 10; May 26 10) aa_222.c2|; May 13 10 | May 26 10 IBBee see. | May 26 10 | June 12 10) bb aan May 26 10 | June 12 10 COA | June 12 10 | June 25 LOS CCS eee June 12 10 | June 25 10 DD s- June 25 10 , July 10 LON dds June 25 10 | July 10 10 13D Seen July 10 10 | July 28 LOM ees oa July 10 10 | July 28 10 RE aS | July 28 9| Aug. 12 GO) hii eee July 28 10 | Aug. 12 63 GiGe rs -| Aug. 12 4| Sept. 1 Ae gee Aug. 12 1 | Sept. 1 1 15113 aaa | Sept. 1 10 | Sept. 17 | ® nhs ce Sept. 1 8: || Sept. 17) [Passes 1 Experiments discontinued. 2 Several. 3 Series sent from Washington, D. C., to Minneapolis, Minn. 4 Inoculations made from material from dried leaves. 5 Series sent from Minneapolis, Minn., to Washington, D. C., October 8, 1907. 6 Extreme heat in greenhouse. , 7 Not recorded. 40 THE RUSTS OF GRAINS IN THE UNITED STATES. Tasie III.—Summary of experiments to determine the vitality of successive uredo genera- tions of various grain rusts—Continued, PUCCINIA SIMPLEX ON BARLEY—Continued. Capital letter series. Lower-case letter series. | Number Number Series pee a ofleaves| Date ee Series Fepadtud of leaves| Date pr letter. oie inocu- | matured. pages letter. A inocu- atured.| ° ne 5 latest pustuled. tion. tated. pustuled 1908. 1908. 1908. 6 1Get, «2 a ee Sept. 17 7 | Oct.. 2 4 10 | Oct. 22 AA) Oct.. 2 10 | Oct. 22 10 10 | Nov. 6 10! | dees Se Oct. 22 10 | Nov. 6 10 10 | Nov. 20 9 Vili Nov. 6 10 | Nov. 20 10 9 | Dee. 12 § |ymm.<. 2 Nov. 20 10 | Dee. 12 9 1909. 1909. 7 | Jan. 10 Ties ase Dec. 12 10 Jan. 10 9 1909. 8| Feb. 7 4; 00... Jan. 10 10 | Feb. 7 10 | Feb. 23 10) DD soso. Feb. 7 10 Feb. 23 10 10 | Mar. 14 LON Ge tee. Feb. 23 10, Mar. 14 10 10 | Mar. 30 TO!) SP wee Mar. 14 10 | Mar. 30 10 10 | Apr. 12 Si ese Mar. 30 10 | Apr. 12 6 10 | Apr. 27 LO" thoes See: Apr. 12 10 | Apr. 27 10 4, May 20 78 et es Apr. 27 7 ay 20 7 10 | June 14 1G) Pe -WWiscee ee May 20 10 June 14 10 10 | June 26 LO wine eee June 14 10. June 26 10 10 | July 7 lh 2. eee June 26 10, July 7 4 10 | July 21 10 | yy------ July 7 10} July 21 10 | Aug. 2 10) 27 Se July 21 10| Aug. 2 10 10 (4) (1) | aga 2 fe Anes 8 (!) (@) PUCCINIA CORONATA ON OATS. 1907 1907. 1907. 10| Feb. 19 = Jal BC ne te Feb. 6 10 | Feb. 19 10 9} Mar. 5 9) | Dees ke Feb. 19 10! Mar. 5 10 9 | Mar. 21 CO I ere ee Mar. 5 10 | Mar. 21 10 10} Mar. 30 LG? cares 5 e352 | Mar. 21 10 Mar. 30 10 410| May 7 10! eee Apr. 17 410 | May 7 10 10 | May 26 dQ) | ieee oa May 8 10 | May 26 10 8| June 10 a ee: Eid oe May 27 9 June 10 9 10 | June 23 10 ||| sbeassoeee June 11 10 | June 23 10 10| July 8 LO" USt ae June 24 10| July 8 10 10| July 23 Lif i eee July 8 10 July 23 10 10| Aug. 8 10),| Mikes eee July 24 10; Aug. 8 10 10 | Aug. 23 10: Ghee eee Aug. 9 10 | Aug. 23 10 10 | Sept. 10 TO} errseeeee Aug. 24 10 | Sept. 10 10 10 | Sept. 27 HL Oy es eee Sept. 11 10 | Sept. 27 10 10} Oct. 8 (8) 02 eee Sept. 28 10 | (Oct (8) 9| Nov. 8 Si pees Oct. 17 10} Oct. 29 10 10 | Noy. 18 LOW ng eeneees Oct. 31 10 | Nov. 18 10 9} Dee. 10 Oar e eee So Nov. 20 8 | Dee. 10 8 1908. 1908. 10))\an> 7 10) ste Dec. 12 10} Jan. 7 10 1908. 10 | Jan. 25 10))|\ Gsss<2se4 Jan. 7 10 | Jan. 25 10 10 | Feb. 15 10} u -| Jan. 25 10 | Feb. 15 10 10} Mar. 3 10) || Syeeee ae Feb. 15 10| Mar. 3 10 10 | Mar. 19 10) | gee Mar. 3 10 | Mar. 19 10 10] Apr. 13 105) es ee Mar. 30 10 | Apr. 13 10 10] Apr. 28 10 || nye” Apr. 13 10] Apr. 28 10 10 | May 13 Oi izes te Apr. 28 10} May 13 10 10 | May 26 10) pan eee May 13 10| May 26 10 10 | June 12 10) pb = May 26 10 | June 12 10 10 | June 25 10) | Keer eee June 12 10 | June 25 10 10 | July 10 10" (dda ee June 25 10 | July 10 10 10 | July 28 10) eae aeens July 10 10 | July 28 10 9} Aug. 12 8) iio SSS: | aly 9} Aug. 12 8 10 | Sept. 1 LOWES Sosa Aug. 13 10! Sept. 1 10 1 Experiments discontinued. 2 Pustules vigorous. 3 Series sent from Washington, D. C., to Minneapolis, Minn. 4 Tnoculations made from material from dried leaves. 5 oe eae from Minneapolis, Minn., to Washington, D. C. 6 Several. F THE ACIDIAL STAGE OF RUSTS. 41 Tasie IIT.—Summary of experiments to determine the vitality of successive uredo genera- tions of various grain rusts—Continued. PUCCINIA CORONATA ON OATS—Continued. Capital letter series. Lower-case letter series. Number Number Series D Bet of leaves| Date wee Series Depot of leaves Date pil rasta letter. ee % | inocu- | matured. ret ae hel Bs Pte F inocu- | matured. soda ion. tated pustuled. tion. Teed pustuled. 1908. 1908. 1908. 1908. ERE S555. Sept. 10 | Sept. 17 Q) on aaee Sept. 1 10 | Sept. 17 (Q) 1 Lie Seer Sept. 17 LON Oct 2 Bi tices Sept. 17 TON Oct am, 8 (ese Oct, 2 10 | Oct. 22 OM sooseel| Ole re 10'|/ Oct. 22 10 1 ae Oct. 22 10} Nov. 6 10} kk.. -| Oct. 22 10 | Nov. 6 10 i Ua ee Noy. 63 10 | Nov. 20 | |e) i eee Nov. 6 10 | Nov. 20 10 WEM 2 52.0. Novy. 20 10 | Dec. 12 10) emma ee Nov. 20 10 | Dec. 12 10 1909. 1909. NING =5--| Dec: 12 10} Jan. 10 Si ennesess= Dec. 12 9) Jan. 10 9 1909. 1909. OO 25. Jan. 10 10| Feb. 7 10) |) woes Jan. 10 10| Feb. 7 5 1 £3 Eee Feb. 7 10} Feb. 23 10) PDesese= Feb. 7 10 | Feb. 23 10 OO: Feb. 23 10 | Mar. 14 1K) “Geeases Feb. 23 10 | Mar. 14 10 ORES Mar. 14 10 | Mar. 30 110) io eee oe Mar. 14 10 | Mar. 30 10 BO Se on Mar. 30 10 | Apr. 12 SilSSaec nee Mar. 30 10} Apr. 12 6 Mies: EA oe Apr. 12 10 | Apr. 27 10),| Tso Apr. 12 10 | Apr. 27 10 \U 0 Uj eee Apr. 27 7| May 20 (|| Aebie nee Apr. 27 9] May 20 9 ie May 20 10 | June 14 VOW AW cece May 20 10 | June 14 10 WIWise- =: | June 14 10 | June 26 10 | ww..... June 14 10 | June 26 10 EXER ewes June 26 10} July 7 GQ: soe: eee June 26 10; July 7 10 nyeY, July 7 10} July 21 LOU yee July 7 10} July 21 10 Til i eee eee July 21 10/ Aug. 2 TOW zz eae July 21 10} Aug. 2 10 VAVACAY <2 = = Aug. 2 10 @) (*) aaa......| Aug. 2 10 (©) () . 19 310 5 8 25 (*) 8 1 7 1 26 (4) 10 (4) 25 (@) 8 7 23 10 8 10 23 2 . 10 10 27 10 8 (*) = OL 5 y. 18 9 10 10 i 10 5 3 25 10 A ¥ 15 10 ; : 3 10 5 A 19 10 : z i 13 10 , - 2 : { 28 10 eR Apr. 28 10 | May 13 TH | PAS ee Apr. 28 10 | May 13 10 PACA May 13 10 | May 26 10) Faas ee May 13 10 | May 26 10 BIB oto. c<4 May 26 10 | June 12 105 P bbess-e May 26 10 | June 12 10 COe oss <2. June 12 9| June 25 alkeceeseeee June 12 10 | June 25 10 DD.. June 25 71 July 10 Bi dds June 25 101 July 10 10 216 1 Not recorded. 2 Experiments discontinued. 3 Pustules vigorous. 4 Several. 5 Series sent from Washington, D. C., to Minneapolis, Minn. 6 Lost in transit. 7 Inoculations made from material from dried leaves. 8 Inoculations made from m. 9 Series sent from Minneapolis, Minn., to Washington, D. C. 42 THE RUSTS OF GRAINS IN THE UNITED STATES. TasLe IIl.—Summary of experiments to determine the vitality of successive uredo genera- tions of various grain rusts—Continued. PUCCINIA RUBIGO-VERA SECALIS ON RYE—Continued. Capital letter series. Number Series Date of ofleaves Date Number letter ena inocu- | matured. weve he : lated ee 1908. 1908. 10 Rear July 10 6| July 28 6 I Se Soe July 28 9} Aug. 12 1] () Cee Aug. 13 8| Sept. 1 5 HH......| Sept. 1 10 | Sept. 17 () nee ert, S | Sept. 17 10} Oct. 2 10 | fae ea | Oct. <2 10 | Oct. 22 10 GK se Oct. 22 10| Nov. 6 10 1b ee ee Nov. 6 8 | Nov. 20 8 MME ose 5 Nov. 20 7| Dec. 12 4 1909. | NN... Sec. 12 10 | Jan. 10 8 1909. OOS ee Jan. 10 | Keb. 7 4 tS! See Feb. 7 10 | Feb. 23 10 Ors Feb. 23 10 | Mar. 14 10 Ree Mar. 14 10 | Mar. 30 10 SSE aaa Mar. 30 10 | Apr. 12 10 dA ee Apr. 12 10 | Apr. 27 10 LUO ee Apr. 27 10 ay 20 10 IVE este May 20 10 | June 14 10 WW..:.. June 14 8 | June 26 8 2. Gas eee June 26 10} July 7 10 avec July 7 10 | July 21 9 Diieoccesk July 21 10 %) (4) Lower-case letter series. Number Series betewa cS ofleaves| Date vou letter. rr hceny ret matured pustuled. 1908. 1908. 06S eeaent July 10 4| July 28 4 51 Cee July 28 6| Aug. 12 hh exisene Sept. 1 39] Sept. 17 (?) | EES (2! re hg 10} Oct. 2 10 i;--- -| Oct. 2 10 | Oct. 22 10 Kes Oct. 22 10 | Nov. 6 10 || eee Nov. 6 10 | Nov. 20 10 mms s.2 Nov. 20 9} Dec. 12 9 1909. Ns. ue Dec. 12 10 | Jan. 10 10 1909. |: 00.= 22-5. cSeeee alee 2 (Fi eee ne eee Loe GOs. joao teeee December 2s, 1G. se. k ee ae eee lees (50: ee See oes Pee oe Goes i oc2 scence aoe Tantary: 2a. 100i ce oe ee Cees loo a cee cesceccteev ec bosetuceedeussloue es Serr Mebraary 15,(19075 <= --<2.8.cscemoes I. STAMIIIS: oS ine 5 A: SENEVUN so oe ee Mar IGS 1007-33. 24 == oat ee eee enue = dorsi enor BUS aes Ok oA see Pe Ss APTUAGs LO sf ccc eden eee aaa GO... 6.oocece okaewe| pose 0 fo Pieegey Meee es Se 5 VSSEERNVSREERRPSN KRanTRavaoSRSISsss VANUATY, 25, LOT. o.~ 2 Soe ee ee a = 0. Se accesses aes rs foe eae HMepruary 15, 1907 25228 a2 ase oe See = =< do. 8 ee See dow. ce s38 ee March 16, 1907---<5-26 22.5222 Se. te cc once ns Sees 12h | Se emecce eeee = are rae ee November 20, 1906. ...------------- ie. rubigo-vera cme ccwe = Winter wheat.......-- December 14, 1906 do 3 December 27, 1906 Jannary 25519072. 22225. asec eos oe fro RiGee ty ee ee eae eee November 20, 1906 December 14, 1906 December 27, 1906 January 25, 1007-22 25222 oss see Pebmianry to 9Ol sae ae oe. oe ee March'(6; 1007.2 s23252-ees eee Taste V.—Summary of germination results from uredo aniston kept buried in snow until germination tests were made. Date of germination test. Species. Host plant. incuba- Hours. | Per cent. WMecember 10190622 - = eee =~ -- Puccinia graminis. ---- ee jubatum. -.. Ipinicinpiey ik) Weegee see eeno.3: oe eee Onesie 2 eee ee oe eee iRebritany 9) 1907) soon tae = March! 20, 1907-- = *- 2222 eras. 2 ae do do : December 10, 1906 January 8, 1607. So see 8S February 9, SOO a ane ees =o 5a are March 20, 190722. = eee ae December 10, 1906 December 10, 1996 January's, 1907=-22 -5---e = - ae | oe do ReDruaryvios (Ovo sea ae eee ae oleae Marcli20) 1907 2e oe ce cena --- soe seen December 10, 1906. Janusry:S, 1901 ~ -= so emee = - = aE | mee IN yboia ek Wiles See eee - Se ese March 20) 90S: a2 <2 nc aerate i> = Sam of lean! December 10, 1906...---- i i January 8, 1907.....-.- February 9, 1907. ...-...- March 20) 190 (terse. == esos somes lowes SESSSERSSERSSSELSSERS SSSUSawRSSSSSARSRG aad 216 WINTERING OF THE UREDO GENERATION. 51 The wide variation in percentage of germination in collections made at different times in these experiments is principally due to the fact that spores at the same stage of development and equally well protected can not be obtained twice in succession. It was noticeable that those spores which were just mature and remained well protected under the epidermis of the host were the most viable. In a large number of cases such spores seemed to be as healthy in the spring as they were in the fall. Those spores which broke through the epidermis, dropped off from the old mycelium, and rested loosely in the leaf sheath, seemed to lose their power of germination during the winter and would not germinate in the spring. The winter of 1906-7 in Minnesota was not abnormal, and much of the rust material collected was dug from under the snow and ice. A thaw during a part of January incased much of the material in frozen snow. About February 15 there was another thaw, and the Agropyron repens material in particular became incased in ice, which disappeared during the latter part of March. The tables show that a large per cent of the uredospores of Puccinia gramims on Hordeum jubatum, on Agropyron repens, and A. tenerum, collected from plants in the field, germinated throughout the winter, such germinations having been made November 20, December 14 and 27, January 25, February 15, March 16, and April15. After April 15 such spores were extremely hard to find in the locality under con- sideration, as most of them had germinated in the warm, humid days of early spring. Uredospores of the same rusts on Hordeum jubatum and Agropyron repens, collected November 20 and 23, kept outside until December 10 and then buried in snow, germinated on December 10, January 8, February 9, and March 20. After that date the snow disappeared and the material could be kept no longer. The uredo- spores on Agropyron tenerum were tested only on December 10, on account of the scarcity of the material. Similar experiments with Puccimia rubigo-vera gave successful germinations from material on Agropyron repens from the field November 29, December 14 and 27, and January 25, while the small amount collected on February 15 did not germinate; from material on Triticum vulgare (winter wheat) successful gverminations were made November 20, December 14 and 27, and January 25, while after that date no material could be obtained; Puccinia simplex on barley col- lected in the field germinated November 20, December 14, and Decem- ber 27. After that time no more could be found. Material of all three of these leaf rusts collected on their respective hosts November 20 and 23, kept outside until December 10 and then buried in snow, germinated December 10, January 8, February 9, and March 20. After that date no trials were made, 216 52 THE RUSTS OF GRAINS IN THE UNITED STATES. The uredospores of Puccinia graminis on Hordeum jubatum, Agro- pyron repens, and A. tenerum obtained from the natural field habitat have thus been demonstrated to retain their viability until April 15, and material from the two former kept buried in the snow until March 20 has also been shown to remain viable. Puccinia rubigo-vera on Agropyron repens and Triticum vulgare from the field have been demonstrated to germinate as late as February 15, and Puccima simplex on Hordeum vulgare as late as December 27. After these dates no material could be obtained. A large per cent of the uredo- spores collected in the fall and kept buried in snow since December 10 germinated as late as March 20, 1907. Bolley has shown that spores of Puccinia rubigo-vera collected in Minnesota April 9 and in North Dakota April 13, 1905, were viable (28, p. 649). Together with Bolley’s and Christman’s investigations cited above, these experi- ments demonstrate conclusively that it is possible for the uredo- spores of various stem and leaf rusts to retain their viability through- out the winter in Minnesota, North Dakota, and Wisconsin. How commonly the wintering of the uredospore in these northern States takes place is yet to be determined. Where snow remains throughout the winter, preventing alternate freezing and thawing of material thus covered, the wintering of the uredospore is, perhaps, facilitated. Indeed, it is very probable that the uredospore sur- vives the winter more easily in the north, where snow is continuous during the winter, than in localities where snow covers the ground only at intermittent periods. Then, there is probably as good a chance, if not better, for the uredospore to winter in northern Min- nesota or southern Canada, as in southern Minnesota or Iowa. This view is also held by Bolley and Pritchard (28, p. 643). From Kansas south, it has been proved by Hitchcock and Carleton (57, p. 11) that Puccinia rubigo-vera winters very easily in the uredo stage, and undoubtedly this also holds true for P. graminis. In the springs of 1908 and 1909, the authors personally observed wheat . fields in Texas and Oklahoma. During the latter part of April, 1908, both Puccinia graminis and P. rubigo-vera were extremely abun- dant on wheats at San Antonio, Tex. Farther north, at Amarillo, - Tex., P. rubigo-vera was well scattered April 30, though not plentiful. At Stillwater, Okla., May 7, this rust was abundant. - Wheats at San Antonio, in 1909, were heavily rusted April 4, with both P. graminis and P. rubigo-vera, and the superintendent of the San Antonio Experiment Farm said that a rust was abundant in the grain plats in February. There is, then, an abundance of rust spores in southern wheat fields in the early spring, and, according to investigations cited in this paper, there are also a large number of uredospores of Pucewnia 216 DISSEMINATION OF THE UREDOSPORE. Se gramimis and P. rubigo-vera which have survived the winter in the north and are ready to infect the growing grain. The great problem for rusts in many places of the South, however, -is not how to live over the winter, but how to pass through the extremely hot months of July, August, and September. This is especially true of the cereal rusts in portions of eastern and southern Texas, as volunteer grain is scarce at that time; but in northwest Texas the authors noticed vigorous rust pustules of both Puccinia gramims and P. rubigo-vera on volunteer wheat during September, 1907, so that in the higher altitudes in the Southwest the rust does exist in the uredo form on volunteer grain in late summer and early fall. The early-sown fall wheat can thus become infected with spores from this source, as described later in this paper. DISSEMINATION OF THE UREDOSPORE. METHODS OF DISSEMINATION. Rusts in the uredo stage have been shown to be present in parts of both the North and South at almost all times of the year, and in order to explain their constant menace to the crops of the country it remains only to determine their means of dissemination. Rust spores are extremely numerous, hundreds occurring in a single pustule. They are very light, much more so than dust. particles, which have been known to be carried in the air for hundreds of miles and dis- tributed over large territories in a few days. An example of the carrying power of the air is cited by Klebahn (63, pp. 66-68) who relates that dust clouds arising in northern Africa, March 9, 1901, were driven over a large part of the continent of Europe in the next two days. Corresponding dust showers were noticed March 9 and 10 in Tunis, West Tripoli, and Algiers; early March 10 in southern Sicily; night of March 10-11 in the East Alps; early March 11 in Maingebiet; at 4.30 in the afternoon in Hamburg; and a little after midnight in the Danish Islands (Stege auf Moen). The dust was composed of clay, fine quartz particles, and other minerals, sup- posedly derived from the African deserts. Undoubtedly, rust spores, which are much lighter than these dust particles, can be carried more easily by the wind and air currents over as great, if not greater, distances. Rising into the air, these spores may reach the upper atmosphere and be carried hundreds of miles a day in whichever direction the air currents are moving. In this way innumerable rust spores may be carried from regions where they are plentiful, either by reason of the presence of the ecidial hosts, or overwintering uredos, to regions where grain is in a receptive condition. This interchange of spores between localities may take 216 54 THE RUSTS OF GRAINS IN THE UNITED STATES. place mainly from south to north in early spring and summer and from north to south in late summer and fall. Together with the wintering uredos in the North, such wind-carried spores from the South undoubtedly can cause early infection of the grains, and together with the spores on volunteer grains in the South the spores from the Northern States wafted south may serve to infect the winter erains as they come up in October and November. * That large quantities of rust spores are present in the air at various times has been proved by many investigators. Klebahn (63, pp. 69, 70) constructed cotton plates, leaving them in the open in trees in different places in Germany in the spring and summer at different periods. These cotton plates were then taken down and washed out carefully, and the water examined. Several thousand uredospores of Puccinia graminis and other rusts were found in each cotton mass, as well as innumerable spores of other fungi. /Zcidiospores and teleutospores were found very sparingly. Klebahn concludes that numberless spores are contained in the air and large numbers fall on a proportionally small space. He believes that since grains are almost universally cultivated, and are scarcely ever rust free, tremendous numbers of rust spores are carried into the air in every grain-growing country, and, as a consequence, there is a universal distribution of them. Experiments on this point have also been performed by the authors. On May 22, 1907, plates containing water were exposed for four hours at a time on top of one of the university buildings at Minneapolis, Minn., and also in an adjoining garden. On centrifuging this water and examining the sediment several uredospores were found, of both graminis and rubigo-vera types. Several teleutospores of Puccima graminis were also found. E.C. Stakman performed similar experi- ments at St. Anthony Park, Minn., in April and May, 1910. Plates with water were exposed in the field, outside the laboratory window, and at the top of a water-tank tower at a height of 100 feet or more. The direction of the wind was southeast. April 11, in a plate exposed outside the laboratory window for four hours, several uredos of a graminis form were found. April 11 and 12, from a plate exposed for 48 hours in the field, several uredos were found; and on the same dates in a plate exposed for 48 hours on top of the water tower over 100 feet high, several uredospores of the graminis form were secured. On May 11, Stakman made a similar test and succeeded in germi- nating a uredospore of Puccinia graminis collected from the air at this time. These experiments of 1907 and 1910 were performed before uredospores began to appear in the field in new growth in that locality, and the spores must have come either from uredos wintering over in the North or from uredos borne from the wheat fields in the 216 eo, FIRST APPEARANCE OF RUSTS IN THE SPRING. 55 South where fresh uredos of both Puccinia graminis and P. rubigo- vera forms are plentiful at this time of the year. This furnishes substantial evidence that Klebahn’s suppositions are correct, and rust spores may be considered fairly universal in distribution. VIABILITY OF THE UREDOSPORE. That spores can resist desiccation in air and maintain their via- bility when transported long distances has been proved by Bolley (24, p. 892). In July, 1898, he demonstrated that uredospores of Puceima rubigo-vera, exposed for 12 days on a dry watch glass placed in the sunlight, would germinate 80 to 100 per cent, and on August 4, spores placed in a similar place for 21 days would germinate from 5 to 10 percent. July 25 and August 4, 1898, respectively, the same investigator proved that the uredo of P. graminis would give “‘oood”’ germination after being exposed for 12 days on a watch glass in direct sunlight, and gave 8 to 15 per cent germination after 21 days on a watch glass in a similar position. Ward (102, p. 13) found that uredospores of Puccinia dispersa ger- minated after being kept dry for 61 days; and Miss Gibson, working in his laboratory, kept «cidiospores of Phragmidium for 54 days and uredospores of chrysanthemum rust for 94 days, when they still germinated. Carleton (31, pp. 21, 22), February 3, 1898, germinated uredospores of P. cryptandri collected in Oklahoma, October 8, 1897, and kept as herbarium specimens, and got successful infection on Sporobolus airoides from inoculations made February 6 from the same material. This is an extreme case of the viability of the uredospore when kept in a dry condition. ~ The authors have numerous times shipped uredo material of the cereal rusts through the mails from Minnesota to Washington, D. C., and vice versa, and from Texas to Washington, D. C., and have experienced no difficulty in producing successful infection on grow- ing plants, even after these spores had been lying in the iaboratory for several days after their arrival. The uredospore is thus seen to be sufficiently resistant to be transported long distances in a dry con- diticn by either the wind or other agencies. FIRST APPEARANCE OF RUSTS IN THE SPRING. From ‘the facts cited concerning the viability of the uredospore and its almost universal distribution, the first spring infection of grains in northern latitudes and the infection of grains far removed from the ecidial hosts of the rusts may be explained. Careful observations on the first appearance of rusts in the spring were made at Minnesota in 1907, 1908, and 1909. In 1907, Puccinia rubigo- vera on winter wheat was common up to the middle of April, when - 216 56 THE RUSTS OF GRAINS IN THE UNITED STATES. the old leaves died and the rust disappeared, not being noticed again until June 21. In 1908 this rust was first found in the field June 18, and in 1909, June 9. P. graminis was first found on winter wheat July 26, 1907, July 3, 1908, and July 5, 1909, while ecidia on bar- berries were producing spores in 1907 about June 15, in 1908 about June 1, and in 1909 between June 14 and 26. Generally speaking, * P. rubigo-vera tritici and excidia on barberries appear at St. Paul, Minn., about the middle of June, and P. graminis tritici the first half of July—that is, from two to three weeks after the other two. Puccinia rubigo-vera is believed not to have any excidial stage in this country. If this is so and the impossibility of direct infection from the teleutospore is granted, the appearance of this rust in spring must. be accounted’ for by infection from wintering uredo, either as mycelium or spore, or by infection from wind-borne spores from fields farther south. Both methods are possible, and both un- doubtedly may be employed. That viable uredospores of this rust have not been found between April 15 and the first part of June in the locality under consideration might furnish some argument that infection from wintering uredos is not possible. Considerable light is thrown upon this question by a study of the difference in length of incubation period of rusts under varying conditions. Under the cool temperatures of early spring the incubation period—that is, the time from inoculation until pustules appear—is lengthened from 7 to 10 days in warm weather to between 3 and 4 weeks and possibly more in cool weather. This lengthened incubation period under cool temperatures has been noticed many times by various investigators. In 1910, experiments on this point were performed in warm and cool greenhouses at Washington, D.C. Average monthly..... — 1.64)/— 1.81)—1.22;— 62), —1.31/— 1.20;\— 1.42;— .31)— 1.32)/— 2.22)—1.31 Of 3 crop months— Accumulative ....]— 8.5 |+ 3.50)/+5.90/+ 7.8 |_—6.80/— 4.20/—10.2|— 9 |— 7.6 |— 6.2 |—3.53 Average monthly.|— 2.83)+ 1.16)+1.96,+ 2.60 —2.26),— 1.40 — 3.4)/— 3 |— 2.53)/— 2.06)—1.17 Of month containing } critical period... --- —2 + .20—1.1/4+ .10— .50\— .30|— 3.5 |— 2.7 |— 2.3 |— 2.1 |—1.42 _ The temperature records (Table VII) for this region for the 7-month period preceding harvest and the plotted monthly mean departure from normal (fig. 2) show that in 1903 the average monthly temperature for the 7-month period varied less than one-half a degree F. from normal in all States except Missouri and Wisconsin, where temperatures were high, and in Nebraska, where temperatures were low, the average for the whole region being 0.12 degree F. above normal (/). In 1904 temperatures were subnormal in all States except Texas, Oklahoma, and Nebraska, and strikingly so in Iowa, North Dakota, South Dakota, Minnesota, and Wisconsin, the average for the region being 1.23 degrees below normal (4). In 1905 tem- peratures were again generally subnormal, but not to such an extent over the five last-named States as in 1904, although the general average below normal was slightly greater in 1905 than in 1904 (J). In considering the 3-month period before and during the heading of the grain it is seen that in 1903 the average monthly temperatures were subnormal, with the exception of Kansas, Missouri, and North Dakota, averaging 0.73 degree F. below normal (J); that these temperatures were more subnormal in 1904 than in 1903, with the exception of Texas and Oklahoma, averaging 1.03 degrees below normal (QO); that they were again subnormal in 1905, but more irregularly so than in 1904, with a general average slightly greater than that of 1904 (P). In considering the month embracing the critical period it is seen that temperatures were subnormal with striking regularity over the entire region in 1904, averaging over 2} degrees below normal in Nebraska and Towa, almost 34 degrees in Wisconsin, and over 34 degrees in South Dakota, North Dakota, and Minnesota, with a general average of 2.67 degrees below normal (£). 216 EPIDEMICS. 65 The temperatures in 1903 (Q) and 1905 (S) were also subnormal during the critical period, but with much greater irregularity and not to such an extent as in 1904. To recapitulate, it is seen that although the general average of temperatures for AVERAGE AREA. ea: ie rex. | oneal wa month periods in 1903, 1904, and 1905 were not much dif- ferent, still in those States where the rust attack was most se- vere in 1904, namely, North Dakota, South Dakota, Minnesota, Jowa, and Wisconsin, temperatures for the 7-month period aver- aged generally much lower in 1904 than in 1905, and for the 3-month period aver- aged about the same as in 1905. During the 1-month period temperatures were consistently subnor- mal in 1904, averag- ing 2.67 degrees be- low normal for the whole region; tem- peratures were 34 de- grees below normal over South Dakota, North Dakota, Min- ee IN IN Fig. 2.—Temperature chart, showing average monthly departure nesota, and Wiscon- from normal in several States in 1903, 1904, and 1905. XX, Normal : : ae: line for a 7-month period preceding the maturity of the grain; X’, aut this ay er age be- normal line for a 3-month period preceding the maturity of the ing consi d era bly grain; X’’, normal line for 1 month including the heading period; , 5 K, N, and Q, lines for 1903; L, O, and R, for 1904; and M, P, and lower than, that of S, for 1905. The lines show departure of temperature from normal either 1903 or 1905. during the periods indicated, respectively, the distance between two : adjacent horizontal lines representing 1 degree F. It is seen, then, that : Bees cae ale the unusually low temperature over this region was a very important factor, if not the determining factor, for the prevalence of rust in 1904. Low temperatures made the crop as a whole late. 88550°—Bull. 216—11——5 66 THE RUSTS OF GRAINS IN THE UNITED STATES. Growth was slow and the heading period was delayed and length- ened. The low night temperatures with abundant dews remaining late in the morning were most favorable for spore germination and infection of the growing grain, and a severe rust attack was the result. That rusts were also severe in parts of South Dakota and North Dakota in 1905 was to be expected from the low temperatures that also prevailed during that year in those States throughout the growing and heading period. PREVENTION OF RUSTS. In view of the almost universal distribution of rusts, the great variety of rust forms, their complicated life histories and relation- ships, the ease with which they are distributed, the apparent absence of any weak point in their life history, and the great influence of climatological conditions upon their development, it would seem that there is but little chance to control these fungi or to prevent losses caused by them from year to year. The worker on rusts from an economic standpoint has kept persistently at it, however, and inves- tigations along many lines have been made, a few of which seem to give some promise of success in the future. Three main lines of experimentation have been pursued. These are (1) experiments in spraying, (2) experiments with soil treatments, and (3) experiments in the selection and breeding of varieties resistant to the disease. A comprehensive survey and treatment of these subjects must be reserved for the future, but a few of the more important points will be mentioned. SPRAYING EXPERIMENTS. Some of the first spraying experiments for rust prevention in this country were made by Kellerman and Swingle, in Kansas, in 1891 (61, p. 90). Two varieties of spring wheat, Fife and Bluestem, six varieties of barley, and one variety of oats were used in the experi- ment. The fungicides employed were flowers of sulphur, potassium sulphid, chlorid of iron, and Bordeaux mixture. Spraying was begun when the plants were 2 to 3 inches high and was repeated every eight days, on an average, for 11 successive times. Rains were unusually abundant during the season. Rust appeared plenti- fully on the sprayed plats and apparently no beneficial results fol- lowed the application of the fungicides. Pammel (82, p. 329) made similar experiments with ammoniacal carbonate of copper and Bor- deaux mixture. Three applications were made, but were “entirely useless.”’ Galloway (53, p. 198), in 1891-92, performed spraying experiments at Garrett Park, Md. He used a variety of spraying solutions, among which were Bordeaux mixture, ammoniacal copper carbonate, ferrous ferrocyanid, copper borate, ferric chlorid, ferrous 216 PREVENTION OF RUSTS. 67 sulphate, cupric ferrocyanid, cupric hydroxid, potassium sulphid, flowers of sulphur, and sulphosteatite powder. Treatments were given when the plants were 2 to 4 inches high in the fall and con- tinued until May 16—seventeen treatments in all. In June, in spite of all these treatments, “‘not a leaf coufd be found that did not show the fungus.” The treatments, furthermore, had no appreciable effect on the yield. Under Galloway’s direction, Swingle performed similar experiments in Kansas the same year with Bordeaux mixture, ammoniacal copper carbonate, and potas- sium sulphid. In his experiments ‘‘Bordeaux mixture did to a considerable extent prevent rust, but the other preparations had little or no effect on the disease. In no case did the prevention of rust affect the yield to any appreciable extent.’’ At Rockport, Kans., the same year, Bartholomew practically duplicated the Maryland experiments under Galloway’s direction. Bordeaux mixture seemed to have a fairly good effect, and Bartholomew concluded that ‘‘while no plat was entirely free from rust it is nevertheless a fact that the ravages were reduced to a minimum on the 10-day plats sprayed with Bordeaux mixture and ammoniacal solution of copper car- bonate.” In summing up all of these experiments, Galloway con- cluded ‘‘that the spraying treatments did, in some cases at least, diminish the amount of rust and similarly increased the yield of straw and grain.” Even with the most improved spraying methods known at that time Galloway believed spraying would be imprac- ticable on a large scale. That there was a possibility of making it practicable in the future was conceded. Hitchcock and Carleton further carried on spraying experiments in Kansas in 1893 and 1894 (58, pp. 4-9). They used a large number of spraying solutions. Some of these, particularly potassium bichromate and ferric chlorid, were somewhat effective in preventing rust, but the investigators found it impossible to cover the foliage sufficiently to make them thoroughly efficient. They concluded that ‘‘although the rust can be largely decreased, we can not attain prevention as is done in such diseases as the grape mildew. Furthermore, it is extremely doubtful if spraying of wheat or oats would pay, even if effective.”’ Since these extensive spraying experiments very little work along this line has been done in the United States, although more or less desultory trials have been made. The trouble at all times in spraying for rust has been the impossibility of getting a spraying solution that will cover all parts of the leaves evenly. The more or less waxy bloom which occurs on the leaves of cereals causes the moisture to drop off very easily, and it is almost impossible with any kind of spraying apparatus to wet both surfaces of the leaves equally well. The areas to be covered are so extensive that the expense of spraying 216 68 THE RUSTS OF GRAINS IN THE UNITED STATES. would be very high. It would seem, however, that with modern machinery and the many and varied formule for spraying solutions in existence, interesting results might be obtained with further spray- ing experiments; particularly would this be true in the case of pre- vention of stem rust of wheat (Puccinia graminis), as we now know the critical period for its attack, namely, the heading time of the grains. It would seem possible to limit spraying operations to this period, particularly in years when it falls in a prolonged cold season, thus concentrating the spraying operations. Even under these conditions there is considerable doubt that spraying would ever be of practical value in preventing rust, but the possibilities justify further experiments. The literature on spraying experiments for the prevention of rusts in foreign countries is extensive and can not be reviewed in this bulletin for want of space. Within the knowledge of the authors, no such experiments have been successful from an economic stand- point, though a few have shown some promise. SOIL AND SOIL TREATMENTS. That an excess of some elements in the plant food may predispose a plant more or less to an attacking disease, or that an excess of some other elements may have the opposite effect, rendering the plant more resistant, has not been firmly established. On the contrary, Ward (100, p. 138) has performed experiments to show that nutrition alone does not make for or against predisposition or immunity on the part of the host or virulence or impotence on the part of the parasite. That cereals will absorb sufficient quantities of any ele- ment originally in the soil, or which has been applied as fertilizer, to render them resistant to rust attack is thus problematical. If this were possible it would be a difficult matter to explain just how this resistance is obtained, whether from changed physiology, modi- fied morphology of the host, or from some toxic effect against the fungous parasite. We know, for instance, that excess of certain salts in the soil will change not only the morphology but the physiology of cereals. Harter (54, p. 134) has shown that wheat plants grown in soils made saline by the addition of 0.7 to 1.4 per cent of sodium chlorid ‘‘modified their structure by depositing bloom on the leaf surface, by thickening the cuticle, and by reducing the size of the epidermal cells.’ In other words, the plants assumed xerophytic characters. Physiologically, transpiration was decreased in plants on soil sufficiently saline to cause increase in thickness of the cuticle, and was increased in plants in soil containing soluble salts in pro- portions too small to affect the measurements of the cuticle. Although, as will be discussed later, Ward has shown that the 216 - tee PREVENTION OF RUSTS. 69 morphology of grains has little or no effect upon the resistance, physi- ological effects, such as described, undoubtedly will influence the general resistance or predisposition of plants to disease in some degree, the extent of which has not yet been determined, Experiments in soil treatments for disease prevention have, however, been made from time to time, a few of which will be cited. In 1891-92 Galloway (53, p. 208) at Garrett Park, Md., treated the soil with various chemicals, among which were flowers of sulphur, air-slaked lime, ferrous sulphate, Bordeaux mixture, potassium sulphid, ammoniacal copper carbonate, and potassium bichromate in various quantities and proportions. No practical results were apparent, and he concluded that ‘‘in no case did these chemicals have any appreciable effect on the prevalence of rust.”’ On the other hand, Petermann (83, p. 15) claims that wheat on land fer- tilized with superphosphate rusted badly, while wheat under similar conditions, but manured with Martin slag (a commercial fertilizer), remained almost rust free. He was inclined to believe that the silicic acid present in the fertilizer was an effective agent in preventing rust. Further experiments on the effect of fertilizers on crops, both in the United States and in Europe, have been exceedingly numerous in the last few years, but very little careful attention seems to have been given to their effect on cereal diseases. General observations have been made, however, and it is now well established that where there is an excess of nitrogen in the soil, other things being equal, grains are more severely attacked by rust than crops on soil containing less nitrogen (28, p. 659; 60, p. 245; 76, pp. 72, 73; 95, pp. 263-270). Where barnyard manure has been applied heavily the result is simi- lar, and where grains are grown after a crop of clover, beans, or vetch, rusts may be expected. In fact, it may be generally stated that where soils are rich in nitrogen, producing rank and succulent plant growth, rust attacks will, as a rule, be most severe on account of increased succulence of the plants, increased rankness of growth, delay in drying out after showers and dews, and slight delay in the ripening period. On the other hand, phosphate of lime tends to shorten the ripening period and thus acts as a rust preventive to some extent. Careful observations and experiments along this line in the future should give both interesting and valuable results. Care should be taken, however, to differentiate the results in experiments on fertilizers with relation to rust resistance of cereals. In general, a rust attack is most virulent on a healthy plant. This is particu- larly true of succulent plants in thick stands. As delay in ripening and other effects may also be produced by fertilizers, their relation- ship to the rust must be carefully kept in mind. The effect of such 216 70 THE RUSTS OF GRAINS IN THE UNITED STATES. results on the rust attack might easily be erroneously attributed to the action of certain chemical constituents of various fertilizers on the rust itself. It seems probable that this is the case in the above- cited results attributed to nitrogen-bearing fertilizers, viz, that the fertilizer produced a very luxuriant growth on which the rust attack would naturally be virulent. RESISTANT VARIETIES. CAUSES OF RESISTANCE. That some plants are far more resistant to the attacks of parasitic fungi than otners of the same genus or species has long been noticed, and that this holds true with respect to grains is well established. Some remarkably rust-resistant wheats, such as the durums and the primitive einkorn wherever grown, Extra Squarehead in Sweden, American Club in England, and Rerrarf and Ward’s Prolific in Aus- tralia, are well known. Some of these varieties, however, can not be said to be universally rust resistant. as one variety may be resist- ant to one or more species or biologic forms of rust in one country but will not necessarily hold the same balance toward other forms of rust, or in another country (51, p. 36; 39, pp. 340, 341; 44, p. 249; 43, pp. 141-144; 75, p. 27; 30, pp. 59, 60; 28, pp. 661, 662). Thus, for instance, Squarehead is more resistant toward Puccinia glumarum in Sweden than toward Puccinia triticina, and Rerrarf, while very resistant in Australia, breaks down completely in North Dakota. Numerous instances of this kind might be cited. It has not yet been established to what character of the plant this elusive and seemingly erratic resistance is due. From a large num- ber of inoculation experiments with the brown rust of bromes and from detailed histological investigations of the hosts, Ward (98, p. 303) found that there is absolutely no relation between differences in the morphology of the brome varieties expressed in length of hairs, number and size of stomata, thickness of epidermis, etc., and rust resistance. He concluded: Resistance to infection of the immune or partially immune species and varieties is not to be referred to observable anatomical or structural peculiarities, but to inter- nal, i. e., intraprotoplasmic properties beyond the reach of the microscope and simi- lar in their nature to those which bring about the essential differences between species and varieties themselves. In the study of resistant and nonresistant wheats the same author (102, pp. 38, 39) showed that rust spores germinate on both suscep- tible and resistant varieties and gain entrance to them through stomata, but in the resistant varieties further progress is checked by the rapid deterioration and collapse of host cells around the entering fungus, while in the nonresistant varieties the host cells remain turgid 216 —— Ue Te OE ae PREVENTION OF RUSTS. 4 and healthy for a long time, giving abundant nourishment to the parasite. Marryat (70, pp. 129-137) had similar results in working with two wheats, American Club, a resistant wheat, and Michigan Bronze, a highly susceptible variety. She concluded: We are forced to fall back upon the theory that immunity to disease is due in these cases to the production of certain toxins and antitoxins by host or parasite, or both, which are mutually destructive. Salmon (91, p. 88), working on the barley mildew, was similarly led to believe that disease resistance is due to physiological and not structural peculiarities. Bolley (26, pp. 180-182) is not certain whether disease resistance is due to structural or physiolovical char- acters, but believes it to be due to the latter, from having been able to develop resistance in every strain of potatoes, flax, or wheat with which he has worked. He further maintains: Under uniform conditions of rust infection, all wheats rise rapidly to a stage of marked resistance to general uredospore infection, whether caused by Puccinia grami- nis or P. rubigo-vera, which resistance seems to be characteristic for each variety concerned * * * . The facts point quite clearly to the probable influence of chemical agencies, perhaps toxins, arising from the direct existence of fungous attacks upon the hosts. In my mind there is not the slightest doubt but such attacks origi- nate heritable resistance. . Biffen (16, p. 128), after making numerous hybrids between varie- ties resistant and susceptible with respect to rusts and studying the first and second generations, concluded that “immunity is independ- ent of any morphological character.”’ Orton (81, p. 457), in analyz- ing the nature of resistance of varieties, similarly concluded that “yesistance is due to a specific protective reaction of the host cell against the parasite.’’ To whatever the resistance may be due in the last analysis, it seems to be a peculiar, delicately balanced con- dition of the host against specific parasites, a balance which is not maintained in the same way toward any two species or varieties and which may be easily upset by change in environment of the host. SELECTION AND BREEDING OF RESISTANT VARIETIES. It has long been known that disease resistance is inheritable to a greater or less degree, and on this basis selection of resistant varieties and strains has been going on for some time. Biffen (15, p. 40; 16, pp. 109-128) has recently brought forth experimental results to prove that resistance and susceptibility of cereals to rust are Mendelian characters, and are inherited in Mendelian proportions. He collected a large number of wheat and barley varieties of various degrees of resistance to the three rusts, Puccinia glumarum, P. graminis, and P. triticina, common in England, and then made crosses between resistant and susceptible varieties. The hybridizing was done in 1904, and results of growing these in 1905 and 1906 were reported. With 216 72 THE RUSTS OF GRAINS IN THE UNITED STATES. regard to yellow rust, he found that on crossing susceptible and resistant varieties the offspring was susceptible. Upon self-fertiliza.. tion of these susceptible individuals, resistant and susceptible descend-. ants were produced in the proportion of one of the former to three of the latter, that is, resistance was recessive to susceptibility, the degree of susceptibility being variable. When the degree of suscep- tibility differed in the two parents the hybrid resembled the more susceptible parent in that respect. More important still, the rela- tively resistant forms bred true to these characters in the succeeding generations. Bolley (27, pp. 182, 183), from several years’ work in the selection and breeding of flax and wheat resistant to wilt and rust, respectively, came to similar conclusions, and in addition believes that unit characters of resistance may be originated even from a very susceptible variety by gradually subjecting the crop to disease from year to year. He maintains that these characters may later be inheritable. The authors have been engaged in similar work since 1907, but sufficient results have not yet been obtained to pronounce definitely on the question of the application of Mendelian laws to resistance to rust in these experiments. Detailed results of this work are reserved for future publication. METHODS USED IN SELECTION AND BREEDING. From the foregoing it will be seen that there are three methods in use for the development of rust-resistant grains through selection and breeding. (1) A careful testing and selection of pure varieties to determine which are already resistant; (2) selection of the best individuals or bulk selection from some strain or variety from year to year under fairly constant disease conditions in the belief that disease resistance is accumulative; (3) hybridizing of desirable varieties with some variety of known resistance and selecting the resistant plants. The first method is absolutely necessary before the third can be applied, while the second is possible for any worker along this line at any time. In breeding for resistance to almost any disease, in order to insure rapid progress, the disease must be present every year in sufficient virulence to affect the crop under trial with more or less severity. Cer- tain diseases, particularly rust, occur in epidemical proportions only at irregular intervals. This not only delays results in nonepidemical years but disturbs them in other ways. To overcome these objections, diseases must be promoted yearly on the breeding grounds in every possible way. In order to do this, special breeding plats are employed If one is working for resistance to flax wilt, the breeding plat must be on flax-sick soil; if for drought resistance, on ground particularly 216 ee ———- -— SUMMARY. vo subject to drought; and for rust resistance, on ground where a rust epidemic can be insured. In the case of rust these conditions can be promoted in several ways: (1) By keeping the breeding plats on fairly low ground, where moisture is plentiful but not excessive and where dews remain as long as possible; (2) by planting barberries around or through the plats when breeding for resistance to Puccinia graminis, or by planting buckthorns when breeding for resistance to P. coro- nata; (3) by planting winter grains at intervals through the plat where spring grains are being bred (since the rusts, as a rule, occur earlier on the winter than on the spring grains); (4) and most impor- tant, by collecting ecidio or uredospores in water and spraying on the plants with hand or knapsack sprayers during the evenings at the period when the grains are most susceptible. All of these methods, or modifications of them, are now in use by Bolley (25, p. 48; 27, pp. 177-182), in North Dakota; by Biffen, in England (16, p. 112), at the Cawnpore Agricultural Experiment Station, in India (55, pp. 54-57); and have been employed since 1907 by the Office of Grain Investigations in cooperation with the Minnesota Agricultural Experiment Station. In Minnesota the authors have established a plat where a very virulent rust attack was obtained, even in the sea- son of 1909, in which no stem rust appeared in any of the fields in its vicinity and in which only local infections were reported throughout the spring-wheat States. Breeding of this kind is extremely important and should be carried on by agronomists and plant pathologists at every experiment sta- tion where conditions are such that rust epidemics may occur at any time. To be effective, it must be extensive and must be persistently employed. SUMMARY. (1) Rusts are among the most serious diseases of grains in the United States, causing an estimated annual loss of fifteen to twenty million dollars. In 1904, in the three States, Minnesota, North Dakota, and South Dakota, the loss due to rusts, conservatively esti- mated, was as high as $10,000,000. This paper deals only with the rusts of the small-grain crops, wheat, rye, oats, and barley, including Puccinia graminis, P. rubigo-vera tritici, P. rubigo-vera secalis, P. coronata, and P. simplex. (2) Practically all these rusts are coextensive with their hosts in the United States, but are not serious in all localities. In general, the areas most affected are the valley of the Mississippi and its tributaries and certain coastal areas. In some years even the drier areas may be affected. The stem rust of wheat is of great importance in the hard winter and the hard spring wheat belts, is frequent in Washington and Oregon, 216 74 THE RUSTS OF GRAINS IN THE UNITED STATES. is almost always virulent on the coast of California, and is severe and frequent in the southern half of Texas. The epidemic of 1904 was prevalent throughout the entire Mississippi Valley, extended into the wheat fields of the Canadian Northwest, and even invaded the dry lands. Leaf rust of wheat is also coextensive with the wheat crop and is — more common in many districts than stem rust. It occurs yearly over the eastern half of the United States. The losses caused by it are not comparable to those caused by stem rust. Stem and leaf rusts of oats are coextensive with the oat crop. They usually occur together and are abundant east of the dry belt of the Great Plains region, are paramount in importance in the South- ern States, and extend north to the Canadian border and even beyond. Stem rust of barley is practically coextensive with barley, but is not often present in sufficient quantity to do serious damage. Leaf rust of barley seems to be of recent introduction. It is eco- nomically one of the least important of the grain rusts. Stem rust of rye is probably widely distributed in small quantities and is fairly common, but causes little injury. Leaf rust of rye is widely distributed and very abundant, but causes little damage, as the rust is closely confined to the leaves and the rye matures too early to be appreciably damaged. (3) Botanical characteristics, life histories, and physiological spe- cializations of parasitic fungi may vary with the geographical distri- bution. Eurepean and American forms may be apparently identical morphologically, but are not necessarily identical in their life histo- ries or physiological specialization. That stem rusts on wheat, rye, oats, and barley, both in Europe and America, may produce their ecidia on barberry has been proved, but that they always do so and can not live for more than one season with- out passing on to barberry is disproved by experiment. The ecidial stage of leaf rust of wheat is not known either in Europe or in this country. The uredo stage exists through the winter months, and the rust may live independent of an excidial stage. The ecidial stage of the crown rust of oats occurs in Europe on Rhamnus frangula L. and R. cathartica L. and in the United States on R. lanceolata Pursh., R. caroliniana Walt., and R. cathartica. The ecidial stage of the leaf rust on rye occurs in Europe on Anchusa officinalis L. and Lycopsis arvensis L. It is believed that the European and American forms are identical. The ecidial stage of the leaf rust on barley is not known for Europe or America. This rust seems not to have been previously reported in this country. Rusts exhibit great variety in regard to complexity of life histories; some are confined to a single host species, some range over two or 216 OO SUMMARY. 75 more species of one host genus, while others range over two or more genera and often on different tribes of the same family. What appear to be the same forms macroscopically and microscopically are often physiologically different, and may consist of a large number of strains or varieties conveniently called biologic forms. This fact accounts, to a large extent, for the differences in results obtained by American and European investigators working on what are appar- ently the same species. In an attempt to break down the barriers between biologic forms the writers have been able to transfer rusts in the uredo stage as fol- lows: Stem rust of wheat (Puccinia graminis tritici) from wheat to wheat, rye, and barley, but not to oats; from wheat to barley and then to wheat and rye; and from wheat to barley successively three times and then to oats. Stem rust of barley (P. graminis hordei) from barley to barley, oats, rye, and wheat; from barley to wheat and then to barley, wheat, oats, and rye; and from barley to rye, to barley, and then to wheat, oats,andrye. Stem rust of rye (P. graminis secalis) from rye to rye and barley; from rye to barley and then to barley, oats, and rye; and from rye successively to barley, to barley, and to rye. Stem rust of oats (P. graminis avenae) from oats to oats and barley, but not to wheat or rye. Leaf rust of wheat (P. rubigo- -vera tritici) from wheat to wheat, rye, and barley. Leaf rust of barley (P. simplex) from barley to barley only. Leaf rust of rye (P. rubigo- vera secalis) from rye to rye only. Leaf rust of oats (P. coronata) from oats to oats and barley, but not to wheat or rye. There is a measurable difference in size between the uredospores of the stem rust on wheat and the stem rust on barley. In continuous culture experiments of wheat stem rust on barley and barley stem rust on wheat, the uredospore of the wheat stem rust approached the uredospore of the barley stem rust in size and the barley stem rust approached the wheat stem rust in size. The following points in regard to biologic forms of rusts of cereals may be emphasized: (1) The stem rusts on wheat, barley, rye, and oats are undoubtedly biologic forms of the same species, Puccinia graminis Pers.; (2) these forms are not entirely confined to their hosts, but vary in range in part according to the host plants they have been recently inhabiting; (3) the leaf rusts on wheat and rye are more highly specialized than the corresponding stem rusts; (4) the stem rust on barley has ordinarily the widest, while the leaf rusts on barley and rye have the most restricted range; (5) under favorable conditions all the stem rusts can be carried successfully to the four cereals; (6) when rusts are transferred to uncongenial hosts, if pustules are pro- duced they are small and weak; (7) two biologic forms may inhabit the same cereals without being identical; (8) by gradual variation 216 76 THE RUSTS OF GRAINS IN THE UNITED STATES. and adaptation to varying conditions a rust species widely distributed may form a number of strains or types, differing in physiological reactions; (9) the host plants exercise a strong influence not only on the physiological and biological relationships but in some cases even on the morphology of the uredospore. (4) Rust life histories were very incompletely understood up to 1864-65, when De Bary demonstrated the hetercecism of Puccinia graminis Pers., but numerous citations in literature show that bar- berries in proximity to grainfields had long been believed harmful. From 1865 life-history work on the Uredinez has made rapid strides and the relationships of many European and American forms of rusts, particularly those of P. graminis, have been demonstrated. Whether or not the scidium is an essential stage in the life history of rusts has long been questioned. Many authors believe it serves to reinvigorate the fungus, and this view has been strengthened since the recent discoveries of cell fusions and the origin of the binucleated condition in the zcidium of various rust species. To test this invigoration theory continuous culture experiments from the uredospore of six different grain rusts were undertaken by the writers and 52 successive uredo generations of each rust grown without the intervention.of any other spore form. At the end of these experiments cultures were as easily made and the rusts grew as luxuriantly as at the first inoculation. For this length of time, at least, there is no need for a sexual generation. (5) Whether or not rusts live over winter in the uredo stage has been a mooted question. Investigators in Germany, Denmark, Sweden, England, and the United States have investigated this problem for different rusts with various results. In the United States it has been demonstrated by several investigators that forms of Puccinia graminis and P. rubigo-vera live over winter in the uredo stage. These results have been reenforced by experiments cited in this bulletin, and the possibility of wintering of the uredo of several rusts in the northern latitudes of the United States has been shown. (6) Rusts in the uredo or ecidial stages are present in different parts of the country at all times. Like dust particles, which have been proved to be carried hundreds of miles by air currents, these rust spores may be carried from regions where they are plentiful to regions where grain is in a receptive condition. That large quantities of rust spores are present in the air at various times has been proved by various investigators and by the writers. (7) A severe rust epidemic was prevalent in the important wheat States of the Mississippi Valley in 1904. In an analysis of the climatological conditions of this region for the years 1903, 1904, and 1905, during the critical or heading period of the grain and during 216 ae ae ae SUMMARY. ave - the 3-month and 7-month periods preceding narvest, it is seen that 1905 had more precipitation than 1903 or 1904; the relative humidity was greater in 1905, but the average temperature, though about the same for the 7-month and 3-month periods during the 3 years, averaged 2.67 degrees subnormal over the whole area in 1904 during the month containing the critical period. It was 34 degrees below normal in South Dakota, North Dakota, Minnesota, and Wis- consin, the region most affected by rust in 1904. This average was considerably lower than that of the same period in 1903 and 1905 over the same area. It is believed that this unusually low tempera- ture in 1904 was a very important factor, if not the determining factor, for the rust epidemic of that year. (8) Spraying experiments for the prevention of rusts have been tried from time to time by various investigators, but for the most part without satisfactory results. There is doubt that spraying will ever be of practical value for rust prevention, but as the critical period for wheat, with regard to the attack of stem rust, is now known, further spraying experiments limited to this period may give valuable results. That excess of some elements in the plant food may predispose a plant to disease or render it more resistant has not been firmly estab- lished. That indirectly it will have some influence, by affecting either the physiology or the general growth of the host plant, is very probable. Where soils are rich in nitrogen, other conditions being equal, rust attacks are, as a rule, most prevalent. Experiments in soil treatments for disease prevention have been made by various investigators, but no very practical results have been reported. This field of work is promising and should be further investigated. Some plants are more resistant to attacks of parasitic fungi than others, and it has not yet been definitely established to what character in the plant this resistance is due; but most authorities agree that resistance is due, as a rule, not to morphological but to physiological characteristics. Disease resistance is inheritable to a greater or less degree, and Biffen has brought forth experimental results to show that resistance and susceptibility of cereals to rust are Mendelian characters. Other investigators have reached similar conclusions. There are three methods in use for developing rust-resistant grains through selection and breeding: (1) Testing and selection of pure varieties to determine which are resistant; (2) selection of the best individuals, or bulk selection from some strain or variety from year to year under fairly constant disease conditions; (3) hybridizing of 216 78 THE RUSTS OF GRAINS IN THE UNITED STATES. desirable varieties with some variety of known resistance, and select ing the resistant plants. . In breeding for resistance to disease, the disease must be presi every year. Rust occurs in epidemical proportions only at irregular intervals, and, therefore, in order to breed for resistance to rust special breeding plats must be employed, where the disease can be produced yearly by conditions particularly favoring its propagation. © Wherever efficient breeding of rust-resistant cereals is to be done, such a breeding plat is absolutely necessary. 216 BIBLIOGRAPHY. A list of the literature relating to the rusts of grains which is cited in this bulletin follows: ils 2. 13. 14. 26. 27. Arruur, J. C., and Hotway, E. W. D. Descriptions of American Uredinez. Bulletin 4, Laboratory of Natural History, lowa University, 1898. Cultures of Uredinez in 1899. Botanical Gazette,vol. 29, 1900, pp. 268-276. The eecidium as a device to restore vigor to the fungus. Proceedings of the Society for the Promotion of Agricultural Science, vol. 23, 1902. Cultures of Uredinez in 1900 and 1901. Journal of Mycology, vol. 8, 1902, pp. 51-56. Cultures of Uredinez in 1902. Botanical Gazette, vol. 35, 1903, pp. 10-23. Cultures of Uredinez in 1903. Journal of Mycology, vol. 10, 1904, pp. 8-21. Cultures of Uredinez in 1904. Journal of Mycology, vol. 11, 1905, pp. 50-67. Cultures of Uredinez in 1905. Journal of Mycology, vol. 12, 1906, pp. 11-27. Cultures of Uredinez in 1906. Journal of Mycology, vol. 13, 1907, pp. 189-205. Cultures of Uredinez in 1907. Journal of Mycology, vol. 14, 1908, pp. 7-26. Cultures of Uredinex in 1908. Mycologia, vol. 1, no. 6, 1909, pp. 225-256. . Bary, A. pe. Neue Untersuchungen iiber die Uredineen, insbesondere die Ent- wicklung der Puccinia graminis und den Zusammenhang derselben mit ci- dium berberidis. Monatsberichte der Kéniglichen Preussischen Akademie der Wissenschaften zu Berlin, 1865. Barciay, A. A descriptive list of the Uredinez occurring in the neighborhood of Simla. Journal of the Asiatic Society of Bengal, vol. 56, 1887. Banks, SirJoseru. A short account of the disease in corn called by the farmers the blight, the mildew, and the rust. Annals of Agriculture, vol. 43, 1805. (According to Plowright, 84.) . Brrren, R. H. Mendel’s laws of inheritance and Shs breeding. Journal of Rerealencal Science, vol. 1, 1905. Studies in the inheritance of disease resistance. Journal of Agricultural Science, vol. 2, 1907. Rust in wheat. Journal of the Board of Agriculture, vol. 15, no. 4, 1908. . Buackman, V. H. On the fertilization, alternation of generations and general cytology of the Uredinee. Annals of Botany, vol. 18, 1904. and Fraser, H.C. 1. Further studies on the sexuality of the Uredinez. Annals of Botany, vol. 20, 1906. . Buomeyer. Vom Versuchsfelde des landwirthschaftlichen Instituts zu Leipzig. Fiuhling’s Landwirthschaftliche Zeitung, vol. 25, 1876. . Boutey, H. L. Wheat rust. Bulletin 26, Indiana Agricultural Experiment Station, 1889. The wintering of rust in winter wheat. Agricultural Science, vol. 3, no. 5, 1889. Wheat rust: Is the infection local or general in origin? Agricultural Science, vol. 5, 1891. Einige Bemerkungen iiber die symbiotische Mykoplasmatheorie bei dem Getreiderost. Centralblatt fiir Bakteriologie, Parasitenkunde und Infektions- krankheiten, pt. 2, vol. 4, 1898, p. 855. Experiments and studies upon wheat. Fifteenth Annual Report, North Dakota Agricultural Experiment Station, 1905. Observations regarding the constancy of mutants, and questions regarding the origin of disease resistance in plants. The American Naturalist, vol. 42, no. 495, 1908. Some results and observations noted in breeding cereals in a specially prepared disease garden. Report of American Breeders’ Association, vol. 5, 1909. 216 79 80 THE RUSTS OF GRAINS IN THE UNITED STATES. 28. Boutiey, H. L., and Prirenarp, F.J. Rust problems; facts, observations and theories; possible means of control. Bulletin 68, North Dakota Agricultura] Experiment Station, 1906. 29. CARLETON, M.A. Studies in the biology of the Uredineze. I. Notes on germina- tion. Botanical Gazette, vol. 18, 1893. 30. Cereal rusts of the United States. Bulletin 16, Division of Vegetable Physiology and Pathology, U. 8S. Dept. of Agriculture, 1899. oi Investigations of rusts. Bulletin 63, Bureau of Plant Industry, U. 8. Dept. of Agriculture, 1904. - 32. CHristman, A. H. Observations on the wintering of grain rusts. Transactions of the Wisconsin Academy of Science, vol. 15, pt. 1, 1904. 33. Sexual reproduction in the rusts. Botanical Gazette, vol. 39, 1905. 34. The nature and development of the primary uredospore. Transactions of the Wisconsin Academy of Science, vol. 15, pt. 2, 1907. 35 The alternation of generations and the morphology of the spore forms in the rusts. Botanical Gazette, vol. 44, no. 2, 1907. 36. Cops, N. A. Contributions to an economic knowledge of Australian rusts. Agricultural Gazette of New South Wales, vol. 3, 1892. 37. Davis, A. M. Barberry bushes and wheat. Cambridge, 1907. Reprinted from the Publications of the Colonial Society of Massachusetts, vol. 11. 38. Eruart, B. Oekonomische Pflanzenhistorie nebst dem Kern der Landwirt- schaft, Garten und Arzneikunst. Ulm und Memmingen, 1758. (According to Klebahn, 63.) 39. Ertxsson, J., and HENNING, E. Die Getreideroste, Stockholm, 1896. 40. Ueber die Specialisirung des Parasitismus bei den Getreiderostpilzen. Berichte der Deutschen Botanischen Gesellschaft, vol. 12, 1894. 41 Die Hauptresultate einer neuen Untersuchung tiber die Getrei- deroste. Zeitschrift fiir Pflanzenkrankheiten, vol. 4, 1894. 42 Neue Untersuchungen iiber die Spezialisierung, Verbreitung und Herkunft des Schwarzrostes. Jahrbiicher fiir Wissenschaftliche Botanik, vol. 29, 1896. 43. Welche Rostarten zerstéren die australischen Weizenernten? Zeitschrift fir Pflanzenkrankheiten, vol. 6, 1896. 44, Neue Beobachtungen iiber die Natur und das Vorkommen des Kronen- rostes. Centralblatt fiir Bakteriologie, Parasitenkunde und Infektionskrank- heiten, pt. 2, vol. 3, 1897, p. 291. 45 Vie latente et plasmatique de certaines Urédinées. Comptes Rendus Hebdomadaires des Séances de l’Académie des Sciences, vol. 124, 1897, pp. 475-477. 46 Weitere Beobachtungen tiber die Spezialisierung des Getreideschwarz- rostes. Zeitschrift fiir Pflanzenkrankheiten, vol. 7, 1897. 47 Ueber die Spezialisierung des Getreideschwarzrostes in Schweden und in anderen Lindern. Centralblatt fiir Bakteriologie, Parasitenkunde und Infek- tionskrankheiten, pt. 2, vol. 9, 1902, p. 596. 48. Zur Frage der Entstehung und Verbreitung der Rostkrankheiten der Pflanzen. Arkiy fdr Botanik, Kungliga Svenska Vetenskaps-Akademiens, Stockholm, vol. 5, no. 3, 1905, pp. 1-54. 49. Neue Studien iiber die Spezialisierung der grasbewohnenden Kronen- rostarten. Arkiv fér Botanik, Kungliga Svenska WVetenskaps-Akademiens, Stockholm, vol. 8, no. 3, 1909, pp. 1-26. 50. Evans, 1. B. Pots. The cereal rusts, Annals of Botany, vol. 21, no. 84, 1907, pp. 441-462. 51. Farrer, W. Report on rust-in-wheat investigations. Report of Proceedings, Third Rust in Wheat Conference, South Australia, 1892. 52. Funke, W. Zur Frage iiber die Entstehung des Grasrostes auf Roggen durch den Berberitzenrost. Landwirtschaftliche Centralblatt fiir Deutschland, vol. 12; no. 2, 1864. 216 53. 69. 70. BIBLIOGRAPHY. 81 Gattoway, B. T. Experiments in the treatment of rusts affecting wheat and other cereals. Journal of Mycology, vol. 7, no. 3, 1893. . Harter, L. L. The influence of a mixture of soluble salts, principally sodium chlorid, upon the leaf structure and transpiration of wheat, oats, and barley. Bulletin 134, Bureau of Plant Industry, U.S. Dept. of Agriculture, 1908. . Hayman, J. M. Rust on wheat. Report, Cawnpore Agricultural Experiment Station, India, 1907. . HorneMann,J.W. Om Berberissen kan frembringe Kornrust. Nye Oeconomiske Annaler, vol. 2, Copenhagen, 1816. (According to Eriksson and Henning, 39.) . Hirencock, A. 8., and Carteton, M. A. Preliminary report on rusts of grain. Bulletin 38, Kansas Agricultural Experiment Station, 1893. Second report on rusts of grain. Bulletin 46, Kansas Agricultural Experiment Station, 1894. . JOHNSON, Epwarp ©. Timothy rust in the United States. Science, n.s., vol. 31, no. 803, 1910. . Jorpi, E. Arbeiten der Auskunftsstelle fiir Pflanzenschutz an der landwirt- schaftlichen Schule Riitti. Jahresbericht der Landwirtschaftlichen Schule Riitti, 1905-6, cited in Hollrung, Jahresbericht tiber Pflanzenkrankheiten, 1906. . Ketierman, W. A., and Swinete, W. T. Spraying to prevent wheat rust. Bulletin 22, Kansas Agricultural Experiment Station, 1891. 2. Kuesaun, H. Kulturversuche mit heterdécischen Uredineen. Zeitschrift fiir Pflanzenkrankheiten, vol. 2, 1892, pp. 258-332. Die wirtswechselnden Rostpilze, Berlin, 1904. . Knieut, THomas A. On the prevention of mildew in particular cases. Trans- actions of the Horticultural Society of London, vol. 2, 1817. (According to Klebahn, 63.) 5. Kriinirz, J. G. Oekonomisch - technologische Encyclopiadie, vol. 4, 1774. (According to Klebahn, 63.) . Kian, J. Ueber die Nothwendigkeit eines Verbots der Pflanzung und Anlage des Berberitzenstrauches. Landwirthschaftliche Jahrbticher, vol. 4, 1875. . Loverpo, J. Les maladies cryptogamiques des cérealés, Paris, 1892. . MAGNEVILLE, DE. Mémoire sur la rouille des blés, tendant 4 prouver qu'elle n’est pas produite parl’Epine-vinette. Mém. Soc. Roy. d’Agricult. et de Com- merce de Caen, vol. 3, 1830. (According to Klebahn, 63.) Maaenus, P. Einige Bemerkungen iiber die auf Phalaris arundinacea auftre- tenden Puccinien. Hedwigia, vol. 33, 1894. Marryat, DorotHea C. E. Notes on the infection and histology of two wheats immune to the attacks of Puccinia glumarum, yellow rust. Journal of Agri- cultural Science, vol. 2, 1907. . MarsHatt, W. The rural economy of Norfolk, ed. 2, vol. 2, London, 1795. (According to Plowright, 84.) The rural economy of midland counties, ed. 2, vol. 2, 1790. (According to Plowright, 84.) . Massachusetts Province Laws, 1754-55, vol. 3, ch. 20. . McAtprne, D. The life-history of the rust of wheat. Bulletin 14, Department of Agriculture, Victoria, 1891. — Report on rust in wheat. Experiments in Victoria, 1893-94. Report of Proceedings, Fourth Rust in Wheat Conference, Queensland, 1894. The rusts of Australia, 1906. . Méglinische Annalen der Landwirtschaft, vol. 4, 1818, p. 280. (According to Funke, 52.) . Monthly Weather Review and Annual Summary, U.S. Weather Bureau, 1903, 1904, 1905. . Ottve, E.W. Sexual cell fusions and vegetative nuclear divisions in the rusts. Annals of Botany, vol. 22, no. 87, 1908. 88550°—Bull. 216—11——6 82 THE RUSTS OF GRAINS IN THE UNITED STATES,” 80. Otrve, E. W. The relationships of the zcidium cup type of rusts. Science, n. ~ s., vol. 27, no. 684, 1908. 81. Orron, W. A. The development of farm crops resistant to disease. Yearbook, U. S. Dept. of Agriculture, for 1908. 82. Pamme.t, L. H. Experiments with fungicides. Bulletin 16, Iowa Agricultural Experiment Station, 1892. 83. PeTERMANN, A. Valeur agricole des scories Martin. Bulletin de Il’ Institut Chimique et Bactériologique de l’Etat 4 Gembloux, no. 72, 1902. 84. PLowricut, C.B. A monograph of the British Uredineze and Ustilagineew, Lon- don, 1889. The connection of wheat mildew with the barberry. Gardeners’ Chroni- cle, ser. 2, vol. 18, 1882. 86. Priuireux, Ep. Maladies des plantes agricoles et des arbres fruitiers et forestiers causées par des parasites végétaux, Paris, 1895. 87. Rostrup, E. Rust og Berberis. Om Landbrugets Kulturplanter og dertil hérende Fréavl, vol. 4, Copenhagen, 1884. Mykologiske Meddelelser (IV). Botanisk Tidsskrift, vol. 19, 1894. 89. —— Biologiske Arter og Racer. Botanisk Tidsskrift, vol. 20, 1896. Mykologiske Meddelelser (VII). Botanisk Tidsskrift, vol. 21, 1897, p. 40. 91. Sarmon, E.S Cultural experiments with the barley mildew, Erysiphe graminis, DC. Annales Mycologici, vol. 2, 1904. 92. ScuorteR, N. P. Berberissens skudelige Indflydelse paa Sceden. Landcekon- omiske Tidender, vol. 8, 1818, p. 289. (According to Plowright, 84.) 93. Scuérr, J. D. Reise durch die mittleren und siidlichen vereinigten nordameri- kanischen Staaten, pt. 1, 1788, p. 56. (According to Klebahn, 63.) 94. Scurérer, J. Entwickelungsgeschichte einiger Rostpilze. Cohn, Beitrige zur Biologie der Pflanzen, vol. 3, pt. 1, 1879, pp. 69, 70. ; 95. Soraver, P. Vorarbeiten fiir eine internationale Statistik der Getreideroste. Zeitschrift fiir Pflanzenkrankheiten, vol. 19, pts. 4 and 5, 1909. 96. Tont, J. B. pE. Sylloge Ustilaginearum et Uredinearum, 1588. See Saccardo, Sylloge Fungorum. 97. Tutasne, L. R. Second mémoire sur les Urédinées et les Ustilaginées. Annales des Sciences Naturelles, Botanique, ser. 4, vol. 2, 1854. 98. Warp, H. MarsHatt. On the relations between host and parasite in the bromes and their brown rust, Puccinia dispersa. Annals of Botany, vol. 16, no. 52, 1902. 99. Further observations on the brown rust of bromes, Puccinia dispersa Erikss. and its adaptive parasitism. Annales Mycologici, vol. 1, 1903. 100. Experiments on the effect of mineral starvation on the parasitism of the uredine fungus, Puccinia dispersa, on species of Bromus. Proceedings of the Royal Society, London, vol. 71, 1902. 101. On the histology of Uredo dispersa Frikss. and the ‘‘Mycoplasm hypoth- esis.”’ Philosophical Transactions of the Royal Society, London, ser. B, vol. 196, 1903, pp. 29-46. 102. — Recent researches on the parasitism of fungi. Annals of Botany, vol. 19, 1905. 103. Wrxpt, L. G. Hanndéverisches Magazin, 1805, no. 47. 104. ———— Der Berberitzenstrauch, ein Feind des Wintergetreides. Aus Erfahrungen, Versuchen und Zeugnissen. Biickeburg and Hannover, 1806. (According to Klebahn, 63.) 105. Wrrnerinc, W. A botanical arrangement of all the vegetables naturally growing in Great Britain. Birmingham, 1776. (According to Plowright, 84). A botanical arrangement of British plants. Ed.2, vol.1, 1787. (Accord- ing to Plowright, 84.) 216 INDEX. Zcidium of the grain rusts. Sce Rusts, grain, zecidial stage. ie 8 Agropyron spp., host plants for grainrust...-.-....... 16, 28,32, 45, 46, 49, 50, 51, 52, 57 meroehe spy. Lest plants for grain rust.....:.....:--....20.-2--2.---4.-- 16, 28, 46 maopecutug spp, host plants for graim rust: ....-.-..1--.-.----2222---4--2-- 16 memmophile arenaria, host plant for grain rust. -.-.-...-.--.-.-....-.....--- 16 Rmecnuswemciraalis, host plant for grain rust.:......----:-----------2-+2+--- 14, 74 ' Arrhenatherum elatius, host plant for grain rust ...................222----- 16 Arthur, J. C., and Holway, E. W. D., on inv paeatees of cram rusts® 22.2" 79 on cultures i gee. hag se Ra 13, 14, 28, 39, 33, 79 Australia, investigations relating to the wintering of grain rusts.............. 47 puree. Host planis for-stammemist....2--.2225.5..-.---- S22. f oie. eee 16 Banks, Joseph, on the relation of the barberry to grain rust...........-..----- 30, 79 Bomperry. levisiation to restrict growing... . 2-2-5222 82S See Stk etc -- 8a Te Carleton, M. A., and Hitchcock, A. 8., on investigations of grain rusts.....--- 15-16, 48, 52, 67, 81 Guitamestiraions On oralnemlstseeeeess coe... - = 2 2 Pewee ec 8, 14, 15, 16, 18, 24, 25, 25, 32, 47, 48-49, 55, 70, 80 Cawnpore Agricultural Experiment Station, grain-rust investivations -_....... 73, 81 Cereals. See Grain. Christman, A. H., on investigations of grain rusts............-: - + alos 30, one Be Chrysanthemum, viability of uredospores of rust.................------------ 55 fama arundinacea, host plant for grain rust........:...-..-...------------60¢ 28 Climate, study in robin to rusts, 1903 to 1905..........- ee Cobb, N. A., on the wintering of the uredo stage = grain parts s. LS ee 47, 80 Germecticut, legislation to restrict the growing of barberries.............---.- 29 216 83 84 THE RUSTS OF GRAINS IN THE UNITED STATES. Page. Crataegus. See Buckthorn. Dactylis'spp-, host: plants for gram rust. . 2. 5225.52. 22522 23s eas eee 15, 16, 46 Damage. See Losses. Dangeard and Sapin-Trouffy, on sexual reproduction in the rusts......-.-.-.-- 33 Davis, A. M., on legislation to restrict the growing of barberries.............- 29, 80 Denmark, investigations relating to the wintering of grain rusts.........-...- 46, 76 Derr, H. B., inoculation experiments with grain rusts.......-----..---- 18, 21, 22-23 Disease, methods used in breeding for rust resistance in grain........ 15, 70-73, 77-78 Dissemination of the spores. See Rusts, grain, dissemination. Distribution of rusts. See Rusts, grain, distribution. Eatonia obtusata, host plant for grain rust. .-..-.=-s---2-45-2=-5-=;--= === 16 Elymus spp., host plants'for grain Trust’: .:. =...) .-=2--=<2-- 22-2 - eee 13, 16, 28 England, investigations relating to the wintering of grain rusts ..........---. 46, 76 Epidemics, rust. See Rusts, grain, epidemics. 5 Erhart, B., on the relation of barberries to rust. .-...---2-.-2:25-52-4--- = eee 29, 80 Eriksson, J., and Henning, E., on investigations of grain rusts.... 15,32, 45, 46, 70, 80 on investigations of grain rusts....-..-..- 13, 15, 16, 18, 28, 32, 46, 58, 70, 80 Hyans; I. B. P., on biologic forms of Puccinia.: =... 2.2. -.2--= 22252 27, 80 Experiments, inoculation, with grain rusts 15, 16-28, 33-45, 49-53, 54-57, 59-CO, 75-76 Harrer, W., on investigations of grain rusts. ....--.--- == <-2s <.24s-.2e=ee eee een 53-55, 76 dishibition inthe United: States= 222 >-4- see. 2 eee eee 8-12, 73-74 epidenaits 25-4). 2:5. sosth ae 7-8, 10, 58-66, 74, 76-77 first appearance in the spring: =... =..- 2-4: - 23228 --—e oe 56-58 hetercecisminc<\:6 =<. = 2.22 dese Sees tome eee eee 28, 31, 45, 76 kinds in the United States! 5... 2... 22) 42922 2255-55-= eee 8, 73 life hinlomes=ss 8 - ane Leatagecte cost SL ee 12-28, 74-76 physiological specializations: =... ..2.+---..---2--.2==5 12-28, 74-76, 77 prevention... <2¢ 22.222 -2 > S22-2 + cee Se 66-73, 77-78 relation of American to European forms........-.----- 12-14, 32, 74, 76 resistanceuneplants <2... 20-3. 2c 3.5 ae eae 15, 70-71, 77-78 uredospores, morphological effect of change of host.....-..--- 25-27, 75 viabiligy ‘of Mee spores... ...2-2. }c5koecee eee 33-45, 52, 55, 57, 76 wintering of the uredo generation...........------- 45-53, 54, 57, 58, 76 Rye, leaf rust, occurrence... 8, 12, 14, 15, 24, 27, 28, 32, 34, 41-42, 46, 48, 49, 55, 59, 73-76 spring, use.in inoculation experiments...... 2.05.02. 2-25-52 2e eee iz BLeMITUSL, OCCURTENCe..... 2252. 4.5522 11-12, 13, 15, 16, 21-22, 27-28, 34, 38, 74, 75 216 INDEX. ; 87 Page, St. Paul, Minn., locality of experiments with rusts................----- 49, 50, 56, 73 Salmon, E.S., on investigations of barley mildew.............-.------------- 71, 82 Sapin-Trouffy and Dangeard, on sexual reproduction in rusts ......-.....----- 33 Schoeler, N. P., on the noxiousness of the barberry to grain crops. ......-.-.----- 31, 82 Schépf, J. D., on the noxiousness of the barberry to grain crops........-..----- 30, 82 Peed On, fie in vestirailonn.Ol TUBB... 2- 9... soc -ce snes onto ee 15, 32, 82 Selection, methods used in developing rust-resistant strains. ........- 15, 70-73, 77-78 Paeamanmionriolium, host plant for grain rust......:-.-2...2224..2--2-.---20 28 Soil, character and treatment for prevention of disease.............--..--- 68-70, 77 Sorauer, P., effect of excess of nitrogen on grain rusts..........--------------- 69, 82 Spores, rust, presence in atmosphere at various times..............------ 53-55, 76 Peeceonlanairoides, host plant for rusts. .:..... 5. +...-2---2- 2-2 -2- eles ee ese 55 Saeavanior prevention of grain rusts_:...-.2=+-------:+---+--12-6-.+.---0- 66-68, 77 Pewee. experiments with Tusts...-.222is¢-205- 25012252. ices cc eee 54 ey of bulletin 5 rip SEP Ee Us ese eA ee a SP 73-78 | Sweden, investigations on the wintering of grain rusts...............-...----- 46, 76 Swingle, W. T., and Kellerman, W. A., spraying experiments for prevention Dieta TA Bs ADDe Re een eal es a ee 66, 81 experiments in relation to grain rusts ..........-........---- 67 Teleutospores, stage predominant in leaf rust of barley...............---..--- =a JA Temperature, relation to development of rust....-.---.-..-.-.----- 44, 59, 63-66, 77 Timothy rust. See Rust, timothy. Meneame Host plant lor eran Tust..-..->--- =. 12-2. Sh ecee 222-2282: 16 Triticum vulgare. See Wheat, winter. Tulasne, L. R., on the relation of summer rust to autumn rust...........-..--- 31, 82 red oMimennis Occurrence ON Wheat... 2.3.2. S2<22-0-s22eercssscmeees estes 46 Uredospores of rusts. See Rusts, grain, uredospores. Viability of rust spores. See Pas grain, viability. Ward. Me- on investigations of rusts.......-.....2--.-....- 46, 55, 58, 59, 68, 70, 82 Wheat, leaf rust, occurrence......- 8, 10, 13, 23-24, 27-28, 34, 38-39, 49, 55-57, 73, 74, 75 Period of susceptibility to attacks of rust....:.2..:...........2222---- 60 Prewon, tise im inoculation. experiments. ..../.........-----2<..----- 17 Be RG iastrOUs CleCt Ol TUStl22---¢--52 42852 ean a ncew ec -see2 wees 10 stem rust, occurrence. ..... 9-10, 13, 15, 16, 17-18, 23, 25, 27, 34, 35, 42-43, 56, 75 winter, CT ee er PIG Se Wind, medium of dissemination of grain-rust spores..............--.--- 53-59, 76 WwW indé, L. G., on the noxiousness of the barberry to wheat..............------ 30, 82 Wintering of rust spores. See Rusts, grain, wintering. Withering, W., on the noxiousness of the barberry to wheat.............--- 29, 30, 82 Young, Arthur, on the noxiousness of the barberry to wheat...............--- 30 216 O Uo DEPARTMENT OF AGRICULTURE. BUREAU OF PLANT INDUSTRY—BULLETIN NO. 217. B. T. GALLOWAY, Chief of Bureau. ROOT-KNOT AND ITS CONTROL. BY ERNST A. BESSEY, Professor of Botany, Michigan Agricultural College, and Collaborator, Bureau of Plant Industry. IssueD NovEeMBER 21, 1911. ——— Asses WASHINGTON : GOVERNMENT PRINTING OFFICE. 1911, ee bia . De ee i ih “ u BUREAU OF PLANT INDUSTRY. Chief of Bureau, BEVERLY T. GALLOWAY. Assistant Chief of Bureau, WmLLIAM A. TAYLOR. Editor, J. E. ROCKWELL. Chief Clerk, JAMES E. JONES. CoTTON AND TRUCK DISEASE AND SUGAR-PLANT INVESTIGATIONS. SCIENTIFIC STAFF. W. A. Orton, Pathologist in Charge. H. A. Edson and J. B. Norton, Physiologists. W. W. Gilbert, L. L. Harter, H. B. Shaw, F. J. Pritchard, F. A. Wolf, and H. W. Wollenweber, Assisi ; ant Pathologists. C. F. Clark, G. F. Miles, Clara O. Jamieson, Ethel C. Field, W. B. Clark, and A. ©. Lewis, Sci Assistants. E. C. Rittue, Joseph F. Reed, J. Rosenbaum, and L. O. Watson, Assistants. 217 x LETTER OF TRANSMITTAL. U. S. DEPARTMENT OF AGRICULTURE, Bureau oF Puiant INpustry, OFFICE OF THE CHIEF, Washington, D. C., April 10, 1911. Srr: I have the honor to transmit herewith and to recommend for publication as Bulletin No. 217 of the series of this Bureau a manu- script entitled “‘Root-Knot and Its Control,” by Dr. Ernst A. Bessey, professor of botany, Michigan Agricultural College, formerly a plant pathologist in this Bureau and now a collaborator of the Bureau of Plant Industry. This bulletin presents the results and conclusions of studies made by the author while in the service of the Bureau. Root-knot, which is widespread through the warm temperate and tropical zones of the whole world, is especially prevalent in this country in the South, and, as the bulletin shows, it is present even in the cold parts of the Northern States. It is also a very serious dis- ease of greenhouse plants all over the country. Fortunately, it is almost exclusively confined to the lighter types of soils, causing little or no damage in stiff clays. Dr. Bessey has worked out under field conditions a practical method of holding the pest in check. The means of its control in greenhouses had already been worked out, so that the methods presented here for controlling the pest in green- houses offer little that is new. The list of plants susceptible to this - disease is more complete than any previous list published, contain- ing more than double the names of any other list. Respectfully, Won. A. TayLor, Acting Chief of Bureau. Hon. JAMEs WILSON, Secretary of Agriculture. Se) 217 a wyy i sat woe ioteiat ef wid eit ay ART MORAST, 10 TATA , 1 . . neonited, a cama rerum vealT so Gaaeuel ou“) are wo lore . 7 i to ini 45 To’ oA” elintivG en ni Jou) th Yous ' loti atin » PF soe : iP anvil afl rod toin.t omit aifal 7 1 srwwreres vce line anal st tee J fuk gudlate OAD al alee Ww all i qeohile a nid ae lit vie siphon 1 2a thy erence 4‘ aj)ebaehteo 1) st Pentre, a3 Fe ve i'-efytAiel OCR + Fi. wee ip of beunjioo 7 ee p - i Veh Se Ba i ‘ALY Virde-wag et fin A lom” Te viene An < » sone ay eet 4S) ial ribs. a, hy 1 210 ae i= my. 1a ‘ wmv be Jatid oleaat wild edsliediag’” or 4 tinfe! 4H 4 cel oUlloting F ba Viareagh. \sv Introduction CONTENTS: EMER TUOU ARTO G 5 an oo ce oe ampere ae. p oe ess 2524'S 55 ae SRE MnneaGtRNGt. 4°... . .. ee Ieee eS ERS 2 2 > s\n .0)5 Ree he SER MEME EI EO TOOt-KNOG-2 2 5 ee ee Sos once cette ede nko newows Praesmamziiected by root-mnot: 9226.39. eI as SS on. Pee ee SIN. Peete AD, OS PCEIMMICNIS ... 22... 2/2. = asec ee So Seep ete sae wma does Sree RIE RETR OL TOOL GG. Joe nee os ae i ot ULI, TSS Se ea poets ae pe een a ae eee Pee at zeeicctae oe- a ere TTE TEER 2 oS Sn A eS RO No ok IR ne eee Comparison with Heterodera schachtil...... Shit Fie a tn OE PE MMMAPEEE EIR CAMOED eee en ae 3 teert eae ee renee ee em sa ae aie eae SRE SeeMEIINIE PMI. seere” Soe te Pie eet Seen er eae oe nl aoe Ses Temperature Gotan gimcoot-INOts..2= ces coace eens = foxes eee 5 La oer Se EAR AE ONG Peecurodses jKecd beds setes. arin shel eee gee ah eo, el ee es ROR a 5 Aha, < isc nee. si tc ee ey NO AD id Uk de (DESL (re Se ee ee Soe eg ie eR Sete PW C8 | DoSTRDEED Ea 000 ON Ne IY WRC CHA ITCOUS eee ae eee ens eee eM ee le cn 20, nn eee Control of root-knot in the field on perennial crops...-...-.---..---------- 8; anil Call ees teem 2S 2 Te ary le Ae es ly ee Flooding Grd DCEMU NFS] ENG ee See, enn | ne ey ieee rere asec e IP GiASatiTh pst pNOCATDODALC <5 = sees ees oe on ts a ae GERDA pect 5. Se See eR ae Sina. 5) 21s 5 eidiac open ee CHER EPCAT ON nee oo oes eater eee Pe ee as oo a oes vee eee Control of root-knot in the field when no crop is present........-....------ TLL SPIT! It weave opines SR oie Balinese in 6.0 2. he So am Mee ae RA Caeeeu DAHA No fon ee ee eee 2 tl RO ee aunrald ekivd Che. see eee sss = BPR eee ee © 1S eel CS oe Palciim Cae id ee os eke sas oe. Bee hoes is gos be eee Potassinm nl phoeanbonates 6 26 SAh 3548 has cic oe 2s eer Se SHE Cte SHE ALE oc e ce wes oso. 2 os os ccs tease LENS s HHI OsPeT UE wee pepe inh all denial aod. o< cay! SAR a, eae ee Flooding i i 6 CONTENTS Control of root-knot—Continued. Control of root-knot in the field when no crop is present—Continued. Page. AGRO PW a0 22. ons oS ons Seep aecee wake aC eee ee aa een 61 PAI nis.Sa sca scin a's we yon sides ve sd nas been ee Sas ashe eee S yee een 63 Pal OW co cccece o's acceso Eh SE ee a Cee a 64 Nonsasceptible crops.... 20 - . - 2 e 2. ones eee 2 eee ee 65 Recommendations for freeing a field from root-knot..............-----.--.-.- 69 Breeding strains resistant to root-knot...........--...------------ - =. Serene it SUMMAaryon.sessasece ete tcc css hi ieiesstatise tee stsesesesecs See 72 Bibliopraphy s22..2s2s2ueee e222 225022.255< steers ietesset ee eee eee 76 Description: of plates: -s-<22s2s2-c22t 3252222 bctstc bal astelt sts eeee ee 82 Widex o2::csscecersecgsserssés2etsecussrse see ees hietrees ses ee ele eee 83 ILLUSTRATIONS. PLATES. Page. PuaTE I. Stages in the development of Heterodera radicicola (Greef) Miill., ete. 82 II. Fig. 1—Root-knot on sugar beet. Fig. 2—Root-knot on squash... ... 82 III. Fig. 1—Root-knot on carrot. Fig. 2—Root-knot on clover.......--.. 82 TEXT FIGURES. Fic. 1. Heterodera radicicola. Half-grown female (?) individual shortly before the final molt. ..........2:..4-5-+222-464-52>44.eeeeeeee 28 2. Anterior portion of same nematode shown in figure 1.............-.: 29 3. Larva of Heterodera radicicola.........---.-+--+.----- e522 eee 29 217 “* ROOT-KNOT AND ITS CONTROL. B. P. 1.—667. INTRODUCTION. The disease of plants known as root-knot, beaded root-knot, root- gall, eelworm disease, big-root, and probably under other names has been present in the United States for many years and has caused losses whose extent can not be calculated. Although more abundant in the South, it is present, at least sporadically, in all but the most Northern or Northwestern States as an out-of-doors pest and is every- where distributed in greenhouses. SYMPTOMS OF ROOT-KNOT. The presence of root-knot becomes noticeable when the affected plants become dwarfed or begin to die, but it is often present and causing a great reduction in the crop yield without the grower’s knowledge. Indeed, it is probable that greater actual loss occurs from the form of the disease where, to the untrained eye, no signs are visible than in the case where the plants are actually killed, for a farmer soon learns by experience not to plant in infected regions those crops liable to total destruction, while he fails to notice a reduction in yield, especially if the disease be well established and not a recent introduction, so long as the affected plants do not show too great dwarfing or discoloration. Aside from the killing or dwarfing of the plants in severe cases or the reduction of yield in less serious infections there are no very noticeable symptoms apparent on those parts of the plant above ground. if rainfall has been rather scanty during the summer, the affected plants first show the lack of sufficient water, while sometimes the wilting is apparent when the sun is hot, even with abundant soil moisture. Occasionally no discoloration is noticeable, but usually plants that are badly affected show a lighter shade of green than un- affected plants. Since, however, the disease usually occupies large areas when it has been long established, there would be no opportunity ordinarily to compare affected with unaffected plants in mass, so that this difference would be readily overlooked. On the roots, on the contrery, very marked structural changes are apparent. Instead of being smooth and of uniform or slowly 217 > ‘ 8 ROOT-KNOT AND ITS CONTROL. decreasing diameter toward the tip, they show irregular enlargements which involve the whole root if it be small or sometimes only one side of a large root. (Pls. II and III.) These are not superficial swell- ings only slightly attached to the root, as in the case of the bacterial tubercles of leguminous plants, but are integral parts of the root itself. On small roots these swellings may vary from only slightly greater than the thickness of the root to twice as thick, and spherical to spindle shaped; on larger roots they are usually lateral, or in bad cases may involve all sides, making a gall many times the normal diameter of the root and covered with furrows and seams until the root loses all semblance of its normal appearance. Such compound knots may reach a diameter of 3 or, rarely, even more centimeters and a length many times as great. HISTORY OF ROOT-KNOT.! Root-knot has been known for many years both in the United States and abroad. It was apparently first mentioned in print by the famous mycologist Rev. M. J. Berkeley,? who described and figured roots of plants affected by this disease and recognized the animal na- ture of the organism causing it. The galis were observed by Greef on grass roots in 1864, but it was not until 1872 that the parasite received a name,’ Anguillula radicicola Greef, after it had been observed sev- eral times on a number of different plants. In 1879 Cornu described this species, observed by him on sainfoin in 1874, as A. marion. In 1882 and 1885 the well-known plant pathologist, Prof. A. B. Frank, described it as a serious enemy of a number of cultivated plants in Germany. In 1883 and 1884 C. Miller made a careful study of the organism causing the disease and placed it in the genus Heterodera under the name of Heterodera radicicola (Greef) Miller. He showed it to be a close relative of the destructive sugar-beet nematode Hete- rodera schachtii Schmidt, which has caused so much injury to the beet- sugar industry in Europe and which the writer found in 1907 in scattered localities in the United States. Treub in 1885 described as a parasite of sugar cane in Java what he considered to be a new species, naming it Heterodera javanica. This is considered now by most authors to be a synonym of H. radicicola. In the United States the root-knot early attracted the attention of greenhouse men as a serious pest of roses, violets, and other plants. J. N. May states ‘ that he saw the disease, which he calls ‘‘club-root,” on violets in 1876. We find the florists’ papers full of references to 1 The full titles of all papers mentioned in this bulletin will be found in the ‘‘ Bibliography,” pp. 76-81. The a,b,c following a date, if given, refer to the first, second, and third papers published if more than one paper in that year fs referred to. 2 Berkeley, 1855. 8 Greef, 1864 and 1872. 4 May, 1888. 217 . Ee OEE HISTORY OF ROOT-KNOT. 9 this trouble in the late eighties and early nineties. The first extensive investigation in this country was undertaken by Dr. J. C. Neal,} of the Florida Agricultural Experiment Station, for the Division of Entomology of the United States Department of Agriculture. Owing to lack of access to literature he did not identify it with the pest previously described in Europe, but gave it the name Anguillula arenaria. Dr. N. A. Cobb,? then of New South Wales, in the absence of specimens from America, provisionally accepted Neal’s species as distinct from the European species, renaming the former Tylenchus arenarius and the latter T. radicicola. He described the injury caused by it in New South Wales, and gave recommenda- tions as to treatment. In 1889 Prof. G. F. Atkinson, then connected with the Alabama Polytechnic Institute, at Auburn, Ala., described the disease, paying special attention to the life history of the parasite, which he correctly identified with the European species. In 1898 Stone and Smith, of the Hatch Agricultural Experiment Station, published the most complete account yet written of the treatment of the trouble in greenhouses, at the same time giving some excellent illustrations of the parasite in various stages of development. In 1892 Géldi described a nematode parasitic on the roots of coffee in Brazil under the name Meloidogyne exigua. This proved subse- quently to be identical with Heterodera radicicola. Finally, in 1901, Lavergne, evidently misled by an erroneous statement as to the dimensions of Heterodera radicicola, described this species from Chile as Anguillula vialae. The foregoing is by no means a complete list of the publications on the subject but embraces the papers that bear on the question of its synonymy and its occurrence in this country. The synonymy of the causal parasite is, then, as follows: Heterodera radicicola (Greef) Miiller, 1883. Syn. Anguwillula radicicola Greef, 1872. mariont Cornu, 1879. arenaria Neal, 1889. vialae Lavergne, 1901. Heterodera javanica Treub, 1885. (?) Tylenchus arenarius Cobb, 1890. radicicola Cobb, 1890. Meloidogyne exiqgua Géldi, 1892. The writer’s investigations of the subject were begun in 1900, but were soon interrupted for a period of years. Not until 1905 was the work resumed in earnest and pursued with various inter- ruptions until its completion. The work was done partly at Washing- ton, D. C., but mainly at Miami, Fla., at the Subtropical Laboratory and Garden of the Bureau of Plant Industry, and at Monetta, S. C., 1 Neal, 1889. 2 Cobb, 1890. 217 10 ROOT-KNOT AND ITS CONTROL. the majority of the field experiments being made at the last-named place. In addition to this, trips were made to the various parts of the country where the disease occurs or was suspected to occur. The caring for the experimental plats at Monetta, as well as the making of many of the observations on these experiments, was performed by Mr. J. M. Johnson, without whose services much of the writer’s work would have been impossible. At Miami the cooperation of Mr. P. J. Wester, at that time gardener of the Sub- tropical Laboratory and Garden, was also of considerable assistance, although the experiments there were not on so large a scale as at Monetta. PLANTS AFFECTED BY ROOT-KNOT. The nematode causing root-knot seems to be one of the most omnivorous known. Neal, in 1889, reported about 65 species of plants as more or less subject to attacks by this pest. Reports by other investigators in different parts of the world and extensive experiments and observations by the writer have increased this number to 480 species and subspecies. Of this total number the writer has personally observed it on 291. The most complete list hitherto is that of Dr. Kati Marcinowski,t who lists 235 species (after subtracting hosts reported under two names). Almost all of the more important families of flowering plants are present in the list, as well as one gymnosperm and a fern. The plants include monocotyledons and dicotyledons, herbs and woody plants, annuals and perennials. Most of the garden plants are affected, as are many field crops. The list of plants shown in Table I is sure to be largely added to as investigations of this disease are carried on, and is not to be looked on as being in any way final. It is true that the writer has made many hundred examinations of plants in badly infested soil that did not take the disease, but such a list is of far less value than that of plants known to be susceptible. In the list are given (1) the scientific name of the plant;? (2) in parenthesis, the name under which it was reported, if different from the name now used; (3) the common English name, if any; (4) the name of the person first reporting it on that host; (5) the date of observation; and (6) the degree of injury. Where the disease is reported on the host for apparently the first time, the name of the first observer is omitted, the observation having been made by the writer. In all cases where the writer has seen the plant 1 Marcinowski, Kati, 1909. 2 The nomenclature followed is that used by the systematic botanists of the Bureau of Plant Industry. The list was submitted to the Office of Taxonomic Investigations of that Bureau, where it was revised by Mr. Homer C. Skeels. In a number of cases it would have been impossible, without seeing specimens, to determine to which of several segregates of a species the plant listed might belong, and in that case the original species name was retained, if still valid. 217 _ PLANTS AFFECTED BY ROOT-KNOT. 11 affected, whether previously reported or not, the name in the first column is preceded by an asterisk (*). In the last column the letters indicate the degree of injury only on those plants observed by the writer, the severest injury observed being reported, even though less severe cases have been observed—a=severe injury; b=nematodes abundant, but injury apparently not great; c=nematodes not abun- dant and no injury observed. It must be understood that under different circumstances many plants marked ‘‘a’”’ would show little injury, while plants observed as uninjured and noted as ‘‘c” might easily be severely harmed under different conditions. Too much dependence can not, therefore, be laid on this column. In a number of cases the writer has grown in very badly infested fields plants reported by others as susceptible to root-knot, without the slightest signs of infection. Such cases are indicated in the list by a dagger (f). Some of these cases may be of species that are susceptible only under special conditions, while others may be due to erroneous observation on the part of the first observer or perhaps to the confusion of the bacterial root tubercle with the nematode gall. The former surmise may explain why the writer during a three years’ residence in a part of Florida where the disease is very abundant failed to find it in any species of Citrus. Dr. H. J. Webber and Prof. P. H. Rolfs, who have studied plant diseases in Florida for many years, confirm this. Yet Dr. J. C. Neal* reports it as occurring on lemon, orange, and bitter- sweet orange, while a similar report is made by Lavergne from Chile? In the list those names added on the authority of Marcinowski 3 are indicated by a double dagger ({) before the name of the plant. TasLe I.—List of plants susceptible to root-knot. [An asterisk (*) is used to show those plants which the writer has found affected with root-knot, and a dagger (t) those which he has grown in infested fields without infection, while a double dagger ({) shows the names of susceptible plants added on the authority of Marcinowski. In the last column a=severe injury; b, nematodes abundant, butinjury apparently not great; c, nematodes not abundant and no injury observed.] Date of | Charac- Name of plant. Name of observer. observa- | ter of tion. injury. * Abelmoschus esculentus (L) Moench. Okra....| Neal..............-- 1889 a IR TEGU EU Teh acer s Satay Bes Boe ieee - - are(S eo» 2,5 aces) fests sats b Panres-preeatorius li Paternoster beantscs.--..|- sce ss-.----.-.-.<|s-.22eeg c *Abutilon avicennae Gaertn. Chinese hemp....|........-..--------.|-------- b PREAIIE e ras a=» (25s maa oe ew od Adiainson,. ....-,- - - J] BS89 Ye22.%- Srermmramemmbir Little). 29-1 Bes oie a nc imo SURE AS § « + ois,a(apd- See Ee b Sense, several species from Australia. Wat- | C. P. Lounsbury‘..| 1908 |...... tle. LUD ae en oe ee eee Le i eer A889 4)... Ma eRELNE COMNZOVEE Vs. ajc ion ee ccc eee ceee Breda de Haan..... £899- git 2. OPTS, 5 aS ee ee ee eee Zimmermann .....- 1900-—1 |. ....-. Agropyron repens (L) Beauv. (Triticum repens).| Greef...........-.-- ae Poe eae Quack-grass. 1 Neal, 1889. 2 Lavergne, 1901. 3 Marcinowski, 1909. 4Tn letter. 217 12 ROOT-KNOT AND ITS CONTROL. TABLE |.—List of plants susceptible to root-knot—Continued. ' Date of | Charac- Name of plant. | Name of observer. observa- | ter of tion. | injury. ATA PODHINR hn settontisdn < Lem aaray gaat | A bo) 5 os See eee Pe 1905-1 |...-.- Alliaria officinalis Andrz. (Erysimum alliaria).. Trotter. .........-- 1905-1 To veer “Allium ascalonicum LO Shallot 22. i... 222.02. ee a st cee b BoP cr. Sh Sem 0 clo ee i es cn one NNN eA | oni iiaeaae b *Allvem jistulosum L. “Welsh onion.-........2.)..------<=---+ +. 5--2)ee eee b *Alliion porrum ls? Beek eee OSS ee [aves TGR AL ae eRe c * Alithaeg zaxea (1), Osy: |, Hollyhoek. 5. - AEP ARS Trotter: s2s2e45-" 1905-1 |. - 222. o oes oe LD 1 we EGICMIMUS HUOTIOR AOU sent ae eo cele g's > ware onl aie dG. sarees 1200 Fo ae {Clematis lanuginosa Lindl. and Paxt..........|..--. re = pagina hg 1900 ¢. cae *Clematis paniculata Thunb. ..22. 5... =. 2 ce< sen] c0 samen oes os ae a {Clematis patens Morr. and Decais.......------- CHMMOL 22 aimee 1900 fon anee CPG AMO, Ji. oon oe ae ss ses eee DOE RM s. 3s aaa eee 1879-2 |-----5 tClematis wheetla Vi... oon. oo canst s-pnpen ean CRIB OG oe an ee 1900 joo nsns CIPMGUS AD. 2b cop pcs seo ee ce oe. coos = 2 | eee ee TRS dts eae *Cojfea aabicd 1," Coffee: {22 22... 25 22 =| ED berb. -. 2 ee ee 1878 a Coffea liberica Hiern. Liberian coffee.....-..- Bouquet de la Grye.| 1899 |...... Coffea robusta Hort. Robusta coffee..........| Cramer........-..-- 190G Lace Coleus blumei Benth. (C.verschaffelti). Coleus.| Frank........-..--- 1385 ease Coleus scutellarioides (L.) Benth. Coleus... .. Breda de Haan..... 1900 lees Coleus sp. (Coleus var.sp.). Coleus.........- Weg. zs: = a oe ee 1889 Jags *Corchorus olitorvus L. Jute..--<-.-.....--2.5-|-s2--02 55255 -- 5505 > a en b *Coriandrum sativum L. Coriander........: -22)s-3-26+ -2.¢6 4-35 =a one c *Coronopas, procumbens Gilib. . oie. - - «sien noe e4|-== aan S- =F FP - en c Corylis avellana L.. Wilbert.--22.-.-..:--.---) Casali....2-.. 22 er 1898 aes *Cosmos bipinnaius Cav. Cosmob:.....--o2sccles-> e--eci-*- eee oe leontodontoides Allioni. Hawk’s- | Trotter...........- 1905-1 doe ass eard. ERIS PILOT O As. oc oe te eee a+ ops opeetegs Darboux and Hou- | 1901 |...... ard. *Crotalaria guneca L: Sunn hemp......------.-|.22---2--geeens-=--F eal eee c *Croton glandulosus simpsontt Fetg....-.------|- 2. --52ee-- - 225-92 eeeeeee ec *Cucumis melo L. Muskmelon............-..-- Neal: eee 1889 a *Cucumis sativus L. Cucumber..............-- Berkeley-<..-- peas 1855 a *Cucurbiia gnanma Duch.- Squash... -.--.-- ice: ---c2522 epee -=- eee a *Cucurbita moschata Duch. Squash...-----....].--.---2--- ---2=-.=5)-eeeee a *Cucurluta pepo L. Pumpkin, :aquash....- > 2}. - - Sec 25 2 seer See a Cuminum cymimam L. ‘Cumm.....--.-.-=---| Erkos --o 7 eee TSS Le *Cyamopeis tetragonoloba (1..) Taub. - Guar... 3}... -...--. 2-2 2222 - oe b {Cyclamen europaeum L. Cyclamen.....-...---. Peslion. 2. o> -: ete ha Ee Cyclamen persicum Mill. Cyclamen........-- Osterwalder.......-. TL «Lc ae *Cydomia oblonga Mill. Quince... -- 2220-22 ¢2aes aoe = eb ee > - =F ~ eee b *Oyperus esculentus 1s. Chiifa........:.5.---2-|-2-00++ 222 05-56=> =e en *Dactylis glomerata L. Orchard prasg... +. ---|--..-- --=-;¢* -- 37 -- eee ¢ Dahlia pinnata Cav. (D.variabilis). Dahlia...) Neal.......--..----- 1889 |... 22. Datisca spqunogin Ni. oo ee ne ee eed Trotier. p30 one aoe 1k i *TDmiqus carota ls. \Oartot.ccea-- --- senses Lacopolizs ns as 1877 a Desmodiniguv sp. 2s ~ ct weed ow nea esheets po f8) 1s RO ee TIO!) Vesees *Deuizia crenata 8. and Z. Deutzia.. . 2.2220 lee een =p == 2 ee a * Dianthus barbatus li. “Sweet William. :222- ols 32s) cece eee ee eee =| “Dianthus caryophyllus L. Camation......... (he *Dianthus chinensis heddewigi Regel. Pink....|...-.-.-------------lereeeeee *Dianthus plumorius L. Mak. .....d0s00--2s-r|s52 = teeneen pee == ee eee are tie fenbaein 8p... <> Me ote eee eee Schlechtendal.....- L886» | sare tDioscorea illustrata Hort. Yam............-- WEVA «ci bs - +5 eee 1895 | ler pina *Diospyros kaki L.f. Japanese persimmon. .-.|....-.-.--------+--ele+ee-e02 a *Diospyros virriniana L. Persimmon......... 21.22.2220. ee cee ence ccleceeceee c 217 PLANTS AFFECTED BY ROOT-KNOT, 15 TaBLeE I.—List of plants susceptible to root-knot—Continued. Date of | Charac- Name of plant. Name of observer. observa- | ter of tion. injury. Dipsacus fullonum L. Teasel.........-.----- rank. 25. seer. --o) VASRa ke as 2 {Dipsacus sylvestris Huds.......---.-.-------- Hieronymus... Sra = A Ne xa MPN MMECTIUS Lio <= 3.5 'a:< gan yo a= 2S aiie.n 5 ARECP Te ce 2 3 gr ead Cer pemmcnours iniermedius (.. and G.) Vail--- 2). -|- J-..< 4-56 -- 6 at2nemlonsenens c SMCS SO nono cs 9 pat a = eae se os AE, og ha - SA - S at a a "Panchos, lapias T.” Wyacinth bean or’ Bona- ‘| 25... . 2c. 5 ~ |e = a vist bean. AI Sara co lB 0 a ba ee a c Dracaena rosea Hort. Dragon tree.........-.- Bnegiea se ik} eae ie PEE Pan ECAR 22 ae Sera Yo cic ciao in n= nt neg PE te deems b PPicocnars palustris (L.) KR. Br... .------22- Lagerheim.......... 1) ae eae BRUPISMieCOLacuna(li,) Gaettn. ~kagimillet: e2|2. 2-02 fos eee lee oe C PS Biecnmaeumatcd: (Ly), Gaertn. uWite-Prasd--o-l 2 e e e c ~eamuminnne. oracteatum (Vent.) Andr. Um- |: ...-.2..2222 2.222 l2 ee eee b morteile. Elymus arenarius L. Downy lyme-grass ..... Warmer = os TSh7. ok oes Praise sagas ( Vahl.) DC: (Scarlet tassel |... ....- 0 se .--l wccla--na--0 b flower. peice Wl.» Roquette: 222.2202... seis wk oe hee ao [ee eee G “Hrythrina americana Mill. Coral tree. -....-.-|..-.-...-- 2-222 - ++ -cb ees 5 b TAR TINMLCTISIAGQUY Vy... nna d= = iain d= aos Licopoli TSC ee © * Bgchscholizia eniyornica Chamie, Califormmint: ye. oa. oe a poppy: Eupatorium capillifolium. (Lam.) Small. | Neal................ LSS Oe cee (E. foeniculaceum). Euphorbia cyparissias L. Cypress spurge. --.- Licopoli US ses) tes ae MECN UCAIVS NAR So a8 i555 ciorercinin yo oc Soin 2s ees ws Slaven ohh wl bbe no c Euphorbia peplis L. “Leafy RPUEPC 222250 Mrottens oc 2-43 ce ab! | 55 Re eee Sr MEGMMEREELIGOTE, Vist sate ss 22 PR os oe tie onc seltiade Eo c ‘Tagapirum.oulgare Will. Buckwheat.......2.)25-...--../2..2.0-- i)ee cocae c permeom cars. Meadow fescue... .-.-- 2. Jae. 5. es | c ueneonemuna in. Sheep icsene. ...-. 2-22... loess. - 0-2 2-2 -- ~~~ dehttg aioe, c *Ficus aurea Nutt. Strangling fig. Wild |.................... cepa: b rubber plant. | LOS ie i 27 ER 1 VC a aaa ites oe eae ae 1889 a * Ficus elastica Roxb. Rubber fob NORE ENS: = ERP ere ACS RES Em RP ORE. 5 b * Ficus 8p.” ? (from Natal).. SER sc etars|: ape a eins Soe Sear ge a * Ficus sp.” (from Mexico)... Bee ere | See (ce ee a Bl pI a Filicinae, genus and species not stated. Fern.| Stone and Smith 1898 le * Foeniculum qugare Hille Sweep 1eUUely oe he tie heme ee b “Pragarus auatoenses (1..) Duches. + American |.........-.....-~.1.-¢}ieeeeee b strawberry. Fragaria vesca L. European strawberry. ..... Trotter OOD =I |e 2 eee Pieegmeese- BNChsia-..-. cs. -- Ses «sy aces's J S237 a a POO Ay te es Galinsoga parviflora Cav........-.-.-.....--- MMA ae a. oS TSB oc ccee *Gardenia jasminoides Ellis (G. florida). Cape | Neal..............-. 1889) oe jasmine. enna AMES OLE oe tere a crcl et. oh oar - $e afeaneaaan b *Glycine hispida (Moench) Maxim. (Sojabean.) | Frank.............. 1882 a Soy bean. *Gossypium barbadense L. Sea Island cotton. .| Neal............---- 1889 b *Gossypium hirsutum L. es COLON... = =; ae i 1889 b *Grabowskia glauca Hort. - eR Boe age ere ae b * Hardenbergia monophylla '(Vent.) eRe eS ee ee a Australian sarsaparilla. Siaarem. coronarum tr, Sulla... 2. . 2. |e ee. ~ ob ~~ san «fen ga seas a Helianthus annuus L. Sunflower. .......---- Neale 20h on 1S SOs eee * Helianthus debilis Nutt. Sunflower.. Se 56 tas ee tn. = | See c *Helianthus tuberosus L. Jerusalem artichoke.|...................-|...-.-..| b 1 According to Ritzema Bos (1900-1) this injury is due to another nematode, T'ylenchus hordei. 2 Species distinct from the preceding. 91294°—Bul. 217—11——2 16 ROOT-KNOT AND ITS CONTROL. TaBLe I.—List of plants susceptible to root-knot—Continued. Name of plant. | | Name of observer. Date of | Charae- observa- | ter of / tion. | Heliotropium sp. Heliotrope................ Stone and Smith. ..| 1898 *Heleroplsa BP t~- 2 <== eae oe 2 =| ge eee an eee Hibiscus coccineus Walt. Rose mallow. ....-. | INGa eben peed *..| 1889 * Hibiscus rosa-sinensis L. Hibiscus........... We, a * Hibiscus sabdariffa L. Roselle. ..........-.--- oceneec ics) toes cht Cl * Hibiscus syriacus L. Rose of Sharon.......... Nealcs tos S.c22 88 1889 *Hicoria pecan (Marsh) Britt. Pecan.......---|..... AG sti gs ee 1889 Hordeum: satipum. “Barley 22. -6 22256255 ) "Brotters -” -2) sca 1905-1 Hypericum perforatum L. St.-John’s-wort....|..... Loa geet ay es 1905-1 Hyssopus sp. Hyssop.. See i323) iia eee 1896 Iberis umbellata L. Candytuit.. Lh EE ae ee [} scale paises ie fe 1889 *Thyjsanthes dutna (1i:) Barn. ---.2-/:.-.- 22. --|-eeecet -- 222 -- eee ee Impatiens balsamina L. (Balsamina hortensis). Hragnk.2-, 226. Stee 1885 Balsam. Impatiens kleinit Wight and Arm...........-- G. A. Gammie 1908 *Ipomoea batatas (L.) Poir. Sweet potato-..-.+|.....-.:-2.-5-.45¢.-|-. eee Ipomoea bona-nox L. Moonflower...........- | Stone and Smith 1898 *Ipomoea cathartica Poir. Wild morning-glory.|............-..---.-|..------ *Tpomoea fuchsioides Griseb. Fuchsia-flowered |.............-.-.---)...-+--- morning-glory. Ipomoea lacunosa L.. 3| Atkinson. =202'F_cc25 1889 *Ipomoea purpurea L. Roth. ~ Morning- -glory.. Neat. .i hase 1889 2 ioomben quamoclit L. Cypress vine.......---|...-- YL eee ee eee 1889 *Ipomoea setosa Ker: 2: : 22220252 . os cw feoee cess boa ss 2 eee ne syringaefolia Meissn. Tree morning- |.........-...-.-----|...-.--- glory *Ipomoca sp. “Indian potatosee. -...: - 2.5 1a tess te eee 12 eee *Tresine paniculata (L.) Kuntze....-.-..--.--- jn seee See ba ee mes Bec: Triehpe APISs See ea Ce eee ee - a lsee aes Brice (22a 1905 Iepraaurca Hort=252. 2 ios. - 2 SSE Cornu. . 1879-1 Izora chinensis Lam. (Izora flammea) .......-|.....- dO. ae oe ee 1879-1 zora ‘crocea art... See. . Se Skt eos dp... esas 1879-1 Ligora frasere Wort + 5223 ee. se Sd ee a is and Hou- | 1901 ard. Ifore Bp Pasay Oe.» >. Soe eee - SSeS TEE | Commu. 27 ee 1879-1 Jacquemontia tamnifolia (L.) Griseb. (Ipo- | Atkinson...-......- 1889 moea tamnifolia.) Juglans cinerea L. _Butternut...........-.-.- Neal. 75 22 eae 1889 * Juglans regia L. Persian (English) walnut...)...-- OL aaa ae ee 1889 * Juglans rupestris i pees Arizona walnut... -|: 2.3. 2 tee ae eeee epee tJuneus gerard Coisels.- 22008. 5. ree lees 7 Lagerheim........-- _ 1905 Kadsura sp. (Cadsura) .. ~ eee .| Breda de Haan..... | 1899 * Konig maritima (L.) R. Br. Sweet alyssum. Bearers emer -- *Kraunhia sinensis (Sims) Greene. Wistaria.--.|..-2:.5--------+-----|o-seeeee *Lactuca sativa L. Lettuce... a2 Prauks*... 42 ae 1882 *Lagenaria vulgaris Ser. Goat... Lee s Neal. 222.2. aoe 1889 *Lamium amplericaule L.. Dead nettle. ... 4£--|- 2022. 6-52 Lantana horrida H. B. K. Lantana.........-. J. J. Thornber *...-- 1907 *Lathyrus cicera.L. Lesser chick-pea...5-. 222 )2 24. 2. 22-202 ee *Lathyris odoratus Ti? ~ Sweet pea... <. 2c scesslesone<= 55S Sas e ee |. ap Sa *Lathyrus sativus 3s, Bitte vetch 22s. 22. 2 sles - ae sae eee 2 eee Beet *Lathyrus tingitanus L. Tangier pea soccecceseclewee Oeeitt corre *Lens esculenta Moench. | dhentil.. .- 5: = 22-55. ¢|2 ewan sees eee Bp Be Leontodon hastilis L. Hawkbit.. : Frank. 1885 tLepidium sativum L. Garden peppergrass. . | Voigt age Slaps oe eee 1890 * Lespedeza bicolor Turcz.’ @Bush clover... ....:-]-. 2.2... o2see + c+ 2-5) ee Lcd aio striata (Thunb.) Hook. Japan | Atkinson........... | 1889 clover 1Tn letter. 217 2 Species distinct from the preceding. injury. eee eee eee eee PLANTS AFFECTED BY ROOT-KNOT. iby TaBLE I.—List of plants susceptible to root-knot—Continued. Name of plant. © *Ligustrum ovalifolium Hassk. California privet. *Tinaria canadensis (L.) Dumont. Toadflax...- Linum angustifolium Huds.......-.-------+-- *Tinum usitatissimum L. Flax .......-------- *Lippia nodiflora (L.) Michx. Frog-fruit. *Lobelia erinus L *Lonicera japonica Thunb. Japanese honey- suckle. *Lotus corniculatus L. Bird’s-foot trefoil... .-. Lotus sp *Leucaena glauca (L.) Benth....-.-.......---- *LTucuma rivicoa angustifolia Miq. Ty-ess...--- *Luffa cylindrica (L.) Roem. peuer ors *Lupinus albus L. White lupine......... *Lupinus angustifolius L. pie ee *Lupinus luteus L. Yellow ore Stiseynsee *Lwupinus termis Forsk.......-- * Lycopersicon escu lentum Mill. Tomato........ Malus sylvestris Mill. (Pyrus malus). Apple. . * Malva rotundifolia borealis (Wallm.) Masters. Wild mallow. * Manihot wtilissima Pohl. Cassava.......-.-...- * Marrubium vulgare L. Horehound..........-. * Medicago sativa L. Alfalfa, or lucern...-..--- { Meibomia mollis (Vahl) Kuntze. Florida beg- garweed. * Meibomia stricta (Pursh) Kuntze......-....-- * Melia azedarach L. Umbrella tree............- * Melilotus alba Desr. White sweet clover, or Bokhara clover. MELOOMestTLaLGay (irs) AM mos 02 Sots fo Soest “Melani ecrassijolia Small... s<5 scene sess os Mesembryanthemum sp. Fig marigold........- Modiola caroliniana (L.) Don. (Mu. multifida) . . Mollugo pentaphylla L. (WM. stricta)......... * Mollugo verticillata L. Carpet weed.......-- * Momordica charantia L. Balsam apple...-..--- * Morus alba multicaulis (Perr.) Loud. Mul- berry. * Morus alba tatarica (L.) Loud. Mulberry....- wuomimuigre to. Mulberry:........+.ss0:---- * Morus rubra L. Mulberry... Bel Mulgedium macrophyllum (Willd. *) Orcs Musa cavendishii Lamb. (Musa chinensis). Dwarf banana. * Musa e.seteGmel. Bruce’s banana.....-.... Musa paradisiaca dacca (Horan) Baker (M. dacca). Dacca banana. Musa paradisiaca sapientum (L.) Kuntze. Banana. Name of observer. Trotter. SOrauer- as wan tee AGM SOmM A> San Trottersess sesso eee Brmiket 22. ek ee Date of | Charac- observa- | ter of tion. injucy. 1905-1 |...... 1906 a 1889 b T905=2h Eee 1889 a SOG |aeee ee 1889 c 1889 a 1882 b SO Sten See 1889 b 1SSOs. See. NS SOMMRAE 2 LOOSH RES S845) | SEN [SSS oe USSsmaie oer. L904 NE eee VOSA us PSE: 1892-2 a 1889-1 |...... 1899 b LOGS Kasey. ASTRA Ne Siete Musa rosacea Jacq....-.------ Sow take ee er sie $3 22k Pee * Musa textilis Nee. Manila hemp.. eae Se oe lee: ee ce op b ANI COUMIOASOTUAET Ger ELON Us = see atayatars\ eles 2. tata Pee te oA ibe elas Geer eee a = Nicotiaga tabacum li» "Tobaceo..-.....-.-22+++| JaMSe.-...2-. 22 MPET TNA cys 2h otha bch oat iataiat ichalwiels o> ss + Ned: 5.22 ee L's SOcimumuasticum Vs. - \Basillset2s:-.--2.2-~ Breda de Haan...-. PT AIGIED SP sho ata! pean ot NE Dehn) < aratata ecate oY G. A. Gammie?.... Onobrychis viciaefolia Scop. Sainfoin.......- Cogn... <...ssest o23 1Jn letter. 217 18 ROOT-KNOT AND ITS CONTROL. TaBLeE I.—List of plants susceptible to root-knot—Continued. ! Date of | Charae- Name of plant. Name of observer. observa- | ter of tion. injury. *Ormmithopus sativus Brot. Seradella. ....< si ¢4|> + -dagplae 0- Seat alee oe c *Ozxalis corniculata L. eee BONE). anos ccs 6 |ocne cee seer ene oe eee Opals sirietit Ta. a5 on cen cies Pests ties ie oe «5 oh ol PAT, 2 Joe i 1898 . leaned “PACDUNG DEO OE CODY acia 3 40= bmi ee ' << 2s cles seen abe ae _Appaetie a * Paliurus spina-Christi Mill. _ Christ’s-thorn....|...--...-.-.-.--- mee eee ele b *Panax quinquefolium L. Ginseng........----- Van Hook...-...:--; 1904 a Papaver rhoeas L. Pop Pby-- oe Papyrius papyrifera (L.) untze (Broussonettia NethiS en ~ sts sab fs ga 1889... Jee 83 papyrifera). Paper mulberry. *Paessiforaincarnaia LL... Passion flower... . - 2:4) iesiex!donet ---) oe a *Passiflora pfordti (= XP. alato-caerulea Lindl.) |......-.-.-.--------|------+- a POSSt HONG Bie eee ae ee eee eee - oe ee Maonusite.o6 ter 1888 ‘leoeses *Pastinaca satiwe di, Parsnip taspcce-s.. = -,e05'2 ADKINSON, 2 spose 1889 c *Pelargonium zonale (1..) Ait. Geranium... .ca|es aoe - - igoes8 d= 35-ee b * Peniagoma physalodes (1h.) Wiern: .. . ---..-.-.-|----sgns62a1o038 == a4] ae b *Porilla frutescens (L.) Britt.- Perilla. ......--=|-->-- >-- -- -'-d- epee {Persea gratissima Gaertn.{. Avocado......... Lawvergne..:.%2.---- TOG. obeicrcaeelal */Petroseunumisatvwvum FHotim. Parsley ..-<)ecc|--a2-- 55. ---- 4ae5 oe aa ec *Petuma kybrida Vilm. Petuniainy: - 2: ccc agleewy =. Sk ee eecl-o eo en a iis aconitifolius Jacq. Aconite-leaved |-....----------.---- | ean. *Phaseolus angularis (Willd.) Wight. Adsuki |................-...- |; 2h en a bean. *Phaseolus:-calcoratus Roxb.,.Seeta wean... ...-|- i-cwedesctt --.. asenleee eee a * Phaseolus lunatus L. Lima bean.. = -ApsN@all a4 ot bers - ae 1889 b *Phaseolus max L. Green gram, or mung bean .[/:1.- - s Green oramt.. ... 2. 2 ee |en S22 = we - =o eee es * Phaseolus retusus Moench. Metealfe bean... |-~- -225-.2. 7sa2e-) = lace a *Phaseolus vulgaris L. (incl. P. nanus). Bean.| Neal .....-....-.-- 1889 b Physalis peruviana L. Cape Bhoaeberry : Seetsee C. P.. Lounsbury 1._| 203 ss(eaeees Physalis sp. - ao 2-2.) ebknasens.. <0 eae L889. je eens Pyielees americana L. (2. ‘decandra ). ‘Poke- |..... do... -}1 4s. 222 1889 b wee *Pilea serpyllifolia (Poir) Wedd. Artillery |..---.---.-------... | an c plant. | Piper betle LL. Betel pepper..............-..-| Zimmermann ....... 1900-2 |....-.- Piper nigrum L. Pepper -.:..-|fDelacroumce. 2p eee 1904... [5282 * Piriqueta tomentosa (W illd. ) Hep. K........siiateekate ee 5) aoe b *Pisum-arvense Ly. Field. pea-sc=. - . . ..jagen< -beat> 4- one? 2-2 dee c *Pisum sativum L. Garden pea.......--.-.---- Neal.: 2227 eee 1889 b *Pithecolobium. saman (Jacg.) Benth. Raim.|):22-..:..-t =.-.<-2s|oeeeeeee a tree. Plantago lanceolata L. Rib-grass......-------- Licopolizc<4dt ase == 1877, Janets! Plantago major Ibs , Plantaingst. 2 :.2-22sci<. ranks: eee oe 1880: [eos *Plantagoepe win. kop epe See ae. 2's o> [aces - eee ee © e Platenus sp.) Plane tree Jee)... . 2. 53.2245 Gandara 2. ..252 8 19D. dad tee Plectnanthis sparc be SOR oe eo ee Bramke .! ssej38 =< Sao 1885 j\eeoee= *Pluchea purpurascens (Swartz) DC........-2.+-|------+-+---222+-+--[2--5ees- a *Plumbago capensis Thunb. Cape leadwort....|......---------=----|-s----- b Poaannua L. Annual bluegrass......-...---- Greef scieee cs 2)» (1 8ze eeeueee {Poa pratensis L. Kentucky bluegrass... ....- Hennings... cece es 1898; esis ya Podranea ricasoliana (Tanf.) Sprague (Te- | ©. P. Lounsbury ':.-|) T9083 ))2eoues coma mackennit). * Polianthes tuberora 1... Tulerose....'...-.--..-|- bare sa. sek eee RE a Polygatla oleifera Mort . (Bee as < ~lee scutes Breda de Haan. oe 1899"; |s2Gee * Polygonum nyGropiperovdeg Mich... <7 s - - oe a |e ene =o eel rs PoOlygontim SP soies -<-eele eek ich cs tee "PanMamie ng = eae | L898) beens * Portulaca grandiflora, Hook. \, Portulaca... -.2') esse eee ere b 1Tn letter. 2 Species distinet from the preceding. 217 al PLANTS AFFECTED BY ROOT-KNOT. TaBLe |.—List of plants susceptible to root-knot—Continued. Name of plant. Name of observer. observa- tion. peeriulaca oleracea L.....Purslane.:.--.-2---.2.5| Neale. 2.25 s2cec8% 1889 {Primula auricula L. Primrose..........----- | Dalla Tornevs . ...4. ce 1892 [Primula carniolica Jacq. Primrose.......--.-)..... dors et eee 1892 Prunus armeniacaL. Apricot........-.--.--- INGall Sapte os ape a 1889 Prunus cerasifera Ehrh. (P. m: tala Shoe CON ed eayceeze | 1889 Prunus domestica Vu, “Plum...-....-..:---.- =|... <- Gs: aXe ais ck 1889 Prunus japonica Thunb. (P. nana and P. |..... Dest < 2.43 ote 1889 lanceolata). | *Prunus virginiana L. Choke cherry.......-. [cre 2c AAT e Sp Ses 2a 2 eek eat Paneer. (inom: Mexico), Wherry: 2.2 5-2 )00 os ke wa weasels aoe Seem EL IM PLLA DIE, Ls. AGMA nnn cin pete Siow Lo onset Nee ecco AN *Punica granatum LL. Pomegranate...-....---.|...-. 22.20. e ee neces [eee eens Parus counniunis. 1... Pear. ..2i2i-. 226i 33 a. Pranks p oedu wei ve 1882 Guepus suber, Cork oak. ..--....-.-----2----| Ducomete 2222s 1908 Phodiculanarmoraca, \(L.), .Robimsom.- Hiorse="|22 2 5 ee) ee eles: ie radish. mmmmaran wiitert (ily) Gpeene to: ie les one ales bai Mo yee le slale shess *Raphanus satwwus L. Radish........-..----.-- | Nealuere®. 2 Tei 1889 Sie PaCAOLOGON Qi elre m- MAIOTION Glee | = Se Fh ya coe a tRhinanthus cristagalli L. Rattlebox.......--. | Rarbous and Hou- | 1901 ar wanemenoriune ls. Currants: 2.2. 95: 222: ek @obbs 34) 6zS2s2: 32 1901 *Rosa chinensis manetti Dippel. Manetti rose--|.................-..|.------- *Kosa laevigata Michx. Cherokee’rose..---.--2|.-.. 2.0.2.2... 22 -e0|eo-2-05- maamuararigone Miche.) ROSe cit 7-22ibs Sasa bask Seibold eupheds lo tieesse Rosa sp. Rose........- , Halsted: d4031 «seem: 1891 Rubusidaeus L. Ras pherry. Beet Sto ec ee SElibye-) sc. Seniesa 1896 Rubus subuniflorus Ryab: (R. villosus). Blache Neale®: vessreecan} 1889 berry. Beem mecroelis Mich 2.2.2. 22-2252 - nose seals. =. (GI Oe att pipe: 1889 SEM IAMECLORE) Lie 22S ORTOL 2 2k See ooo IS te) A a ls SS *Rumex sp.!_ Dock.. . oe salar pine But Te a aN see *Saccharum officinarum im “Sugar | eane: oon Breda de Haan....-- 1899 Salix babylonica L. Weeping willow....-....-- Neal jaar 1899 Di AMRENES F SAR Cosco oan ee Ls i Be "Ey enol coe ey as Pn 1896 tSanicula europaea L. Wood sanicle.......-.. Commi art sau shise 1879-2 Pemmenaicalismuaria. Lice. 8 52622 Oe be Ie Soran 7 4ee 1906 Schizonotus sorbifolius (L.) Lindl. (Spiraeasor- | Neal.....-.-.------- 1889 bifolia). *ecoumus hispanicus LL. Spanish‘oyster plantgies. 222020. 222 ceceusa acess eacmconcranispanica 1...” Blackosalsifyireul wanes. sled. 22. scoala ee Be Sedum (several species)........-..----------- TOPE 24 0 34- See 1872 Penepervwvuny quiucihm Tens....2. 20-1... seapebicopoli.. 2... - 1877 PHO PEP PUUUNRCCCLORUM Ling coca 03 -ce ence epee e & doses 5 teh 1875 eR eatie HIGOTIS Ba aie ae 2 be eee ee Meo tier esate tao aS! 1905-1 EB eMemere Py TILOSG (SACG.) SLOG 22 525. 22; San Mes a OPP eee PRU RMR eA ChOCET POM Le ee eats as oce ioe | Lee seme. oA ee Sesuvium maritimum (Walt.) B.S. P. (S. pen- ; Neal.............-.. 1889 tandrum). CRIME DONS LACHSETUTI Micke nots aoe Aa 55 ROR rem, ke rahe A React DEE LUE TEST OE a pea i f°. SMM a pe Aste Pasescr | MONMMRDERORE oooh 36 vas. Ieee ae los Lee ee Agkinsonws... 222 2.2) (A 889e 4 SPU TIUe) CAEN MUL COS Wiel bays) es tt Sah aes ES oc cis. GIES hesctbeise 3 “Holanuncarolimense lu. Horse nettle. . << |asaee exe mond iss .ank aneers Solanum dulcamara L. Bittersweet....-...-- eMigsseri= Sos eney 22/3 | 1903 *Solanum melongena L. Egeplant........-.-. AMANBOMSa os .hsi28 1889 *Solanum nigrum L. Nightshade..............|............-- Lal esas se Exolaniumnirostrarun Mun Bittialo bur cscec.e eee ese mee |e eee | *Solanum tuberosum L. Potato............---- 1.5 Rae ea 1889 19 Date of |Charac- 1 Species distinct from the preceding. 217 ter of injury. set eee 1 20 ROOT-KNOT AND ITS CONTROL. TABLE I.—List of plants susceptible to root-knot—Continued. Date of | Charac. Name of plant. Name of observer. observa- | ter of tion. | injury. "SOMMMUMEBDS 8 oc ~s oadaceeaccrs ss soe ss Su oe b Sonchus arvensis L. Sow thistle...........--.-- ‘Tarnagasicts ; - 0:38 1898’. Mins2 S25 | Nonchus olerdees Tos. 45520 Sele ce ccsi ss | so) ee @.| 1885) ise, *Sperguicarvenma L.. Spurryesi.! 2 2/s---\ j= a's DRS. 3 er c Spermadictyon suaveolens Roxb. (Hamiltonia | Cornu............--- 1879—-Ls|.w2 de spectabilis). *Spinacia oleracea L. Spimach..............--- jsb5. oo. cn Ceyet: Oe b *S piraea cantoniensis Lour,, “Spirea.....-..--<|2-..--.-/2250--- ee aoe b *Spondias lutea LL, log plum ¢.....--.---.--<|S230 3.2200...) Se a PSlENRENOUS Spo c cee oc fee eee oe eee oo Voigt. 202 2050 en 1890: fre SS. *Stizolobium pachylobium. . Piper and Tracy... .|...--.-2220-2. -..-3 2. eeeee b tStizolobium pruriens (L.) Medic.........----- Piper and Cobb?....| 1910 b tStizolobium deeringianum Bort ( Mucuna utilis). | Rolfs......-...---- 1898: (ees Velvet bean. Strelitzia nicolai Reg. and Koern. Bird-of- | Ross.........-...-. 1883: eens paradise flower. *Syncarpia glomulifera (Sm.) Niedenz......-..|---.-2..-222/.1.1-.3). 52s c *Tamorvndus indica L..- Tamarind”... .... 22. -2\..-.=. 023280. 22 See c “hanacetum vulgare ss. . Vanby-scee-: =~ <2 0222s | n aoe eee ee eee b Taraxacum officinale Weber. Dandelion...... Lieopolt..2/.2 ese 1ST7 eee * Tetrapanaz papyrifer (Hook.), Koch. Japanese |...............:.-¢s|s20eeeee a paper plant. Mer sinenss Wi; . Tea. coer. = See ee Barbers222. 3352 I90D i ee tTheobroma cacao L. Chocolate or cacao.......- Ritzema Bos........ 1900. | |2ece # TWeophrasia crassypes Lindl. .ss2.-..--...<-32| Comic e222 aes 1879-41: oo F *Thunbergea fragrans Woxb.tis2ieeg.-..- =... 2.22 |esdetede- «=e a *Tragopogon porrifolius L. Salsify............| Atkimson............ 1889 a * Trichosanthes cucumeroides (Ser.) Maxim...... eluslict 3) vhs ee a y *Trijolium alexandrinum L. Egyptian clover, |.......---.-.---2---|-oeeeeee Ee Berseem. * Trifolium incarnatum L. Crimson clover... .- Hrank.-. Sosa 1885 a *Trifolium pratense L. Red clover......---.-.|.---- do32 ee 1885 a * Trifolium repens L. White clover........---- Sheldon...) sae 1905 a *Trigonella foenum-graecum L. Fenugreek.....|........------------|-------- b Triticum aestivum L. (T. sativum). Wheat...) Sorauer......-.---- 1906. azseeee Triumfetta rhomboidea Jacq. ........--------- G. A. Gammie ?_...| 1908 qo2eeee *Tropacolum majus L. Nasturtium. ---.....-.|---2 222-2 2.-42-2 eee eee ec *Tropacolum minus.L. Dwari nasturtium.::: |. . 2.2.0.5. eee ce * Ulmus campesiris I.. Huropean elm..........|2.-.+--0---.--.2 322-2 a * Verbascum thapsus L. Mullem:. ....22222 9294|5: <2 ese eee eee c Verbesina occidentalis (L.) Walt. Crownbeard..| Neal........-..-.-.-- 1889». 12258: *Verbesina virginica L. (V. sinuata). Crown- |....- do...- beers 1889 e beard. * Veronica peregrina L. “Speedwell. ...2-.-.--.|.2------2-2 2 22-2 | ee ce * Veronica tournefortn Gmehnt =... ..-...-.--2 | o..- Jo4e- e+e oe a eee e {Viburnum lantana L. Wayfaring tree......-.. ramos: (2 Sa) Sige 1896 .4|z2ee8= {Viburnum tinus L. Laurestine............-- Kiefier.. i444 3" 1.90). qe * Vicia atropurpurea Dest... 2262... ... 208. Bes |: J 1 ee c * Vicia faba li. Horse bean.< =. ..22. 2252 2 So de see b * Vicia fulgens Battand. Scarlet vetch....2......|.......- 2.2.50 eee c * Vicia hirsuta (.)'S. ¥. Gigiy-.......-..- =-2-~=|-4-5-+-+22--= eee b * Vicia monanthos (.) Desi®eas: ......-- 2-52). 5.01 2at.=- ee ee a * Vicia narbonensis L.. Narbonne vetch.......2).......-.:.-.--:--s00-|-oeeeeee b * Vicia nseudocracea Bertol @........------2-defise2 220s 2a ee ie * Viewa satwa L.. Vetch. -2ex0s.i.05.2.52.-25. essa eee b * Vic villosa Roth. Hairy vetch......-2...-.}. 422220225... See ee b * Vigna repens Baker. --. 22 .o5<..---ceeeense~o s/t sUeknue Bree =et ae b 1 Species distinct from the preceding. 2Tn letter. 217 PLANTS NOT AFFECTED BY ROOT-KNOT. AN TABLE I.—List of plants susceptible to root-knot—Continued. Date of |Charac- Name of plant. Name of observer. observa- | ter of tion. | injury. *Vigna unguiculata(L.) Walp. (Vigna catjang, | Neal................ 1889 a Dolichos catjang). Cowpea. pr wilmederaig E>‘) Violet. 22.04.2205 ...2524 Halsted 2. 62.0% 1891 a Vitis aestivalis Michx. Grape............... Neth ss ods. cena 1889 ys,|9 x~-x. Vitis labrusca L. Grape... BS as egal ns bi oso 33) Cae Se ty ah OEE Se Vitis serianaefolia (Bunge) Maxim. (Cissus Commu. WIS 1879-2 |.:.... aconitifolia). *Vitis vinifera L. Old World grape. ........ aNCAl wee ss tek Soe 1899 a *Washingtonia filifera microsperma } BeeCari., le gate take HOI |V.) SAL b California fan palm. *Washrnplonia gracilis * Parish 2. 2.2.02 .. 0.02). eee b Willughbaea scandens (L.) Kuntze. (Mikania | Neal..............-- TS99y eee scandens). IMENT NOLS scant sc toe oe ogc: 5 Ss see see loosest: b {Zea mays L. Maize or Indian corn........... Neal 24s 2 2: GR 1889 (Re 1 Seed received under this name from Dr. O. Beccari. PLANTS NOT AFFECTED BY ROOT-KNOT. Among the plants grown by the writer in infected land without their becoming infected with root-knot in the slightest degree were sey- eral species of Stizolobium, the genus to which the velvet bean belongs, viz, Stizolobium lyoni, S. pruriens, S. hirsutum, and the velvet bean and one or more other unidentified species of this genus.!| Many of the grasses seem to be resistant. Thus the writer has failed to find the nematode on crab-grass (Syntherisma sanguinalis), redtop (Agrostis alba), Johnson grass (Andropogon halepensis), some varieties of oats (Avena sativa)—but some are susceptible—Bromus schraderi, Eusta- chys petraea, some varieties of barley (Hordeum vulgare), Lolium perenne, Japanese barnyard millet (Hchinochloa frumentacea), broom- corn millet, or proso (Panicum miliaceum), pearl millet (Pennisetum sp.), timothy (Phleum pratense), rye (Secale cereale), the various forms of sorghums, milos, Kafir corn, ete. (Andropogon sorghum), wheat (Triticum aestivum), but see list of susceptible plants. The same is true of corn (maize, Zea mays) as of wheat. Euchlaena luzurians was also free. Several Compositz seem to be free from the trouble even where the nematodes are very abundant in the soil. Thus, Bidens leucantha and B. bipinnata always were found free. (Gna- phalium purpureum, Helenium tenuifolium, species of Solidago, Zinnia, etc., were also free. The absence of nematodes in the plants above enumerated is far less significant than their presence in other plants, for conditions may have been unfavorable, and yet under other con- 1 Rolfs, however, 1898, reports root-knot on the velvet bean, and recently Prof. C. V. Piper has found it in abundance on plants of Stizolobium pruriens, S. P. I. 21566, grown in a greenhouse in Washington, D. C. Evidently under certain conditions some strains may be susceptible, but as a rule it is immune. 217 22 ROOT-KNOT AND ITS CONTROL. ditions they might have shown root-knot. However, it is probable that the above-named plants will show themselves nematode resistant in most cases. CROSS-INOCULATION EXPERIMENTS. It has been suggested by several investigators that Heterodera radicicola, like Tylenchus dipsaci, may show the development of strains preferring certain hosts and exhibiting a reluctance to attack others, although these different strains are morphologically indis- tinguishable.t| This explanation has been suggested for the fact recorded by Stone and Smith? that lettuce often is not attacked in beds in greenhouses where other crops suffer great injury. The writer accordingly made a number of cross-inoculation experiments to determine, if possible, to what extent the nematodes of certain generally grown crops were interchangeable. The experiments were performed as follows: Pots of soil were sterilized in an autoclave for about an hour and a half, sometimes longer, at a temperature of 125° C. While this was perhaps not long enough to kill all bacterial spores in the center of the pots, the temperature attained showed itself to have been high enough to kill all nematode larve or eggs. Tn the sterilized soil were placed affected roots of the plant used as a source of the nematodes. These roots were first carefully washed (sometimes in water containing a small amount of formaldehyde) to remove all adhering dirt in which conceivably larve or eggs of other strains of nematodes might be present. These pots were planted with seeds of plants to be tested as possible hosts of the nematode, either at the same time or a few days after the roots were put into the pots. Except when it was certain that the water was nematode free, it was boiled and cooled before using it to water the pots. Experiments made in this manner showed that the root-knot nematodes were mutually interchangeable in the following plants: Red clover (7v- folium pratense; Pl. III, fig. 2), white clover (7. repens), crimson clover (7. inearnatum), cowpea (Vigna unguiculata), strawberry (Fragaria chiloensis), tree morning-glory (Ipomoea syringaefolia), sunflower (Helianthus debilis), horse bean (Vicia faba), gimseng (Panaz quinquefolium), purslane (Portulaca oleracea), fig (Ficus earica), papaya (Carica papaya), catalpa (Catalpa speciosa), tomato (Lyco- persicon esculentum), and Old World grape (Vitis vinifera). These all also affect the following, for which the reverse inoculation experi- ments were not made: Lettuce (Lactuca sativa), green gram (Phase- olus radiatus), tobacco (Nicotiana tabacum), squash (Cucurbita moschata), cucumber (Cucumis sativus), and muskmelon (C. melo). 1 Prof. J. Ritzema Bos (1900) reports that Tylenchus dipsaci becomes so adapted toa host plant after growing on that species only for several generations that it will not attack with any severity the species upon which it grew before until several generations have passed. 2 Stone and Smith, 1898, p. 30. 217 DISTRIBUTION OF ROOT-KNOT. 23 The various families of plants represented in the foregoing list and the fact that the infections were obtained easily and very pronouncedly would seem to indicate that the nematode causing root-knot of the plants experimented with, including some of those most generally affected in the field, is not as yet very markedly differentiated into strains peculiar to certain hosts. It is still possible, and indeed quite likely, that had seeds of the same host as that furnishing the roots from which the nematodes came been sown in the pot along with the other seeds the latter would have shown less infection than the other plants. Unfortunately, however, various circumstances prevented this line of experiments from being carried out. Observations in the field seem to bear out the results of the pot experiments. The writer has been unable to detect any special adap- tation to any one species of plant. Indeed, peaches were attacked very badly when planted where cowpeas had been grown for several years. Figs and the Old World grape are the plants through which the parasite has been introduced into many new districts, which could hardly have been done so thoroughly and rapidly if the nematode had become in a manner specialized upon them. DISTRIBUTION OF ROOT-KNOT. Root-knot was first observed by Berkeley ' on greenhouse plants in England [t was next reported by Greef ? on out-of-doors plants in Germany. Since then it has been observed in many parts of Germany, France, Italy, Austria, Holland, Sweden, and Russia. In Africa it is abundant in parts of Algeria, occurring even in some of the Saharan oases, Egypt, German East Africa, Transvaal, Cape Colony, and Madagascar; in Asia it occurs widespread in India, Ceylon, and to some extent in China and Japan. In the East Indies, Java and Sumatra are badly infested. No authentic reports have been received of the presence of this pest in the Philippines, but it is probably to be found there. Several of the Australian States are infested, and the pest is not unknown in New Zealand. In South America it has been reported from Chile, Argentina, and Brazil. It seems also to be widespread throughout the West Indies. In Mexico it is prevalent at many points. In the United States the root-knot is to be found in sandy soil now or previously in cultivation in most parts of North Carolina, South Carolina, Georgia, Florida, Alabama, Mississippi, Louisiana, and Texas, as well as at many points in California. It is not abundant in New Mexico or Arizona, although proving destructive in some of | the irrigated districts of the latter. It is very evidently of recent introduction there, as in many parts of Texas. In the interior of the 1 Berkeley, 1855. 2 Greef, 1864. 217 24 ROOT-KNOT AND ITS CONTROL. West the writer has observed it, only sporadically it is true, in Utah and Colorado and at one place in Nebraska. It is reported, and the writer has seen specimens, from Arkansas. Oklahoma, Tennessee, and Kentucky have no reports of it in the open, but it is probably present to some extent, since it is found along the Ohio River in West Virginia and also in northern Pennsylvania. It occurs, but not in great abundance, in Delaware, Maryland, and Virginia The New England States appear to be almost free from the trouble, so far as outdoor plants are concerned, although it has been observed in Con- necticut and Rhode Island. The most northerly points where it has been observed out of doors in this country are at various points in New York State, on ginseng and alfalfa; northern Indiana; Menomi- nee, in the Upper Peninsula of Michigan; and the locality in Nebraska already mentioned. In the last three instances all the evidence indi- cates that the disease was directly imported from other localities and was not indigenous to that locality. The important point is, how- ever, and this will be reverted to, that this nematode is able to main- tain itself in regions where the winter’s cold may be very intense All of the localities named above are those in which the root-knot nematode has been found out of doors, not merely on plants par- tially protected during the winter, but in soil not at all protected from the severest winter cold. In addition to these localities it is almost universally present in this country in greenhouses and has in a number of instances become more or less established out of doors in their immediate vicinity, where it is protected by compost heaps, etc., from the extreme cold. In the most northern States it need not be feared that the pest will ever become widely distributed. A careful study of the distribution of the disease convinces the writer that root-knot is of comparatively recent introduction in the regions west of the Mississippi. Indeed, it is possible to trace its arrival in parts of Texas, Arizona, and southern California, it having appeared in recent years after the land had been in cultivation for a long time with no signs of injury from such a pest. In Texas the introduction and spread of the nematode has been accomplished almost entirely by means of infected nursery stock, mainly figs, mulberries, and peaches; in Arizona and California figs and the Old World grape seem to be the responsible plants. The scattered localities in the North where the trouble occurs often reveal, on care- ful inquiry, the source of the infestation. Ginseng has been respon- sible for several outbreaks, the nematodes doubtless having been introduced in the moist earth in which the seeds were packed. In other cases nursery stock, such as peaches or even apples, has been responsible; sometimes the soil thrown out from greenhouses has 217 =) THE CAUSAL PARASITE. 25 spread the trouble, and in some cases the manner of introduction can not be determined. Close analysis of all the earlier reports and of the existing distribu- tion of root-knot has convinced the writer that we have to deal with a pest originally tropical or subtropical in its distribution and not native to any part of the United States. In this the writer comes to a conclusion at variance with that of Neal,! who believed that it was native to the Southern States. If that were the case, however, it ought to be found on uncleared land where no crops have ever been grown, but that is not generally the case. Indeed, it is the general practice, when nematode-free land is needed, to go to un- cleared land. To be sure, nematodes are occasionally found in such land, but almost always it can be shown to have been previously in cultivation, perhaps many years ago, or to be so situated that soil from infested fields could be washed upon it. The general trade in exotic plants which began over a hundred years ago and grew rapidly, in the course of which ornamental and useful plants from the Tropics, especially of the Americas, were car- ried to European conservatories and gardens and also to ourshores, may very probably have served to introduce the pest into the tem- perate regions of both the Old World and the New World. In all like- lihood the Spaniards introduced this nematode into Florida directly from the West Indies or Central America, for it is found in parts of southern Florida that were in cultivation more than 75 years ago, but where now dense forests have grown up, as well as in clearings with no signs of recent cultivation. Yet even here it does not seem to occur in land absolutely unused in the past. Whether the Old World or New World Tropics were the original home can not be decided now, as it is widely distributed in both. Perhaps its wide distribution in Africa, India, the East Indies, China, and Japan and the fact that another species of the same genus (Heterodera schachtit Schmidt) is apparently native in Europe would warrant the conclusion that it is probably of Old World origin. THE CAUSAL PARASITE. Upon breaking across a medium-sized or large knot and holding the broken surface so as to reflect the light a close observer will often see one to many clear to almost pearly white rounded bodies, con- siderably smaller than half the diameter of a pinhead, projecting from the surface. With a hand lens they are easily seen, but for the unaided eye they are sometimes very difficult to detect, on account both of their minuteness and of their transparency. In knots that have been cut across they are usually not visible, as they col- 1 Neal, 1889. 217 26 ROOT-KNOT AND ITS CONTROL. lapse when touched by the knife. These objects are the mature females of the nematode Heterodera radicicola (Greef) Miller. Each is capable of laying several hundred eggs, more than 500 having been counted by the writer in one case where the nematode was still actively laying eggs. ; EGG. The eggs (Pl. I, figs. 1 and 2) are ellipsoidal bodies, sometimes symmetrical, more often slightly curved, and therefore somewhat kidney shaped. They are usually a little over twice as long as broad. Out of 71 different lots of egg masses measured by the writer, repre- senting nematodes from 63 different hosts, the length varied from 67 to 128 » and the width from 30 to 52.5 yw. The greatest ranges observed in any one lot of eggs were 67 to 108 by 33 to 42 yp, 88 to 128 by 33 to 44 pv, 81 to 112 by 33.5 to 40 yw, and 84 to 119 by 35 to 52.5 pw. These represented in each case eggs from the same nema- tode, showing how variable in size they may be. The average range of all measurements was 85 to 98 by 34 to 40 » with an absolute average of more than 500 eggs measured of 92 by 38.4 yw. These dimensions agree closely with those given by Miiller,t who studied this nematode in Germany, his figures being 94 by 38 yp. On the other hand, Frank,? also working in Germany, gives the figures as 80 by 40 ». Stone and Smith * give the length as 100 p. When the writer first examined the eggs from different hosts he thought that there might be a possibility of distinguishing different races of the nematode by the variations in the size of the eggs, but the variability in size, even among the eggs from the same nematode, soon demonstrated that no results of value could be obtained in this direction. It seemed to be true, however, that the smaller, less strongly developed females often produce the smaller eggs. Thus, a nematode situated near the surface of a root, where the pressure was not so great, was often larger and had larger eggs, but this rule has so many exceptions that it can not be considered as being in any way general. The egg consists of a densely granular body in which a lighter spot, the nucleus, can occasionally be seen, inclosed in a tough, elastic, transparent coat, or shell, probably chitinous in nature. When the mother nematode is so situated that she has plenty of room to de- posit her eggs so that they are not laid with difficulty, they usually leave her body unsegmented. On the other hand, if the eggs as they are laid are crowded together so that considerable force has to be used to lay each egg, the oviposition is delayed and segmenta- tion begins before the later eggs leave the body. Only exceptionally, however, do the eggs develop so far as to contain fully developed 1 Miller, 1883. 2 Frank, 1885. 3 Stone and Smith, 1898. 21% THE CAUSAL PARASITE. 27 larvee by the time they are laid. Where this does occur it is mostly only the last eggs produced and which the mother nematode has not had the strength to force out against the large mass of eggs already laid. In this the root-knot nematode differs quite markedly from the sugar-beet nematode (Heterodera schachtii Schmidt), m which a comparatively large part of the eggs produced remain within the body of the mother and undergo segmentation and finally escape from the shell, eventually escaping to the outside through the open- ings in the body wall after the death of the old nematode. Segmentation of the eggs begins very soon in any case and proceeds rapidly. It was not determined exactly how long the embryonic development required, but it is apparently not over two or three days in warm weather (much longer in cool). The eggs were laid at the rate of 10 to 15 a day in the cases observed by the writer, although in some cases egg laying may pro- ceed even more rapidly. They are surrounded by a slimy or gelati- nous substance, which incloses them and evidently acts as a pro- tection. This is secreted by the nematode with the eggs, as was observed on isolated mature females under the microscope. It is at first quite liquid and colorless, but soon becomes rather firm and light brown in color toward the outside. This is the structure that has been called by some investigators the egg sack (Eiersack); for example, Voigt 1 and Strubell.? The latter applied the term to the similar structure in the sugar-beet nematode (Heterodera schachtii), and, erroneously, denied its occurrence in H. radicicola. Occasionally the remains of the male may be found entangled in this slimy mass. It is probable in such cases that after fertilizing the female the male died and when the eggs were laid the egg mass sur- rounded his remains. The eggs at the outer portion of the mass are usually either hatched or contain larve, while those next to the body of the nematode are not segmented. This egg mass is sometimes as large as the adult female and can be seen readily when the latter partly projects from the root. LARVA. The larva (Pl. I, figs. 3 and 4) emerges from the egg through a hole which it pierces in the shell, usually at one end. It is a slender, cylindrical animal, blunt at the anterior and tapering at the poste- rior end to a pointed tail. The larve when they emerge from the egg are 375 to 500 » in length* and about 12 to 15 y» in greatest 1 Voigt, 1390. 2 Strubell, 1888. 3 Stone and Smith (1898) give the length of the larva as 350 », but this is considerably less than the meas- urements made by the writer. They give the egg length as 100 », showing that they were not dealing with eggs below the normal size. 217 98 ROOT-KNOT AND ITS CONTROL. thickness. The average length is 420 to 475 ». The structure of the larva is comparatively simple, consisting essentially of a tube (the alimentary canal) within a tube (the body wall), the space between (the body cavity) being filled with a liquid and minor structures (fig. 1). The body cavity has no opening to the exterior. The ali- mentary canal opens anteriorly at the end of the body, but posteri- orly it opens in the median ventral line about one-eighth of the dis- tance forward from the tip of the tail (i. e., 50 to 65 »). The body wall con- sists of an external cuticle and a dermal layer of cells beneath which are the four “‘fields’”’ of obliquely longitudinal muscle cells. Longitudinal _ tissue masses springing inward from the der- mal layer at the median dorsal, ventral, and lateral lines separate the muscles into the four “muscle fields’? men- tioned. Only occasionally the opening of the excretory canal can be made out in the larva, but it is quite distinct in the mature male. It is in the ventral median line, opposite or slightly pos- terior to the esophageal bulb. These details of structure are clearly shown in the accompanying text figures (figs. 1, 2, and 3), contributed by Dr. N. A. Cobb. The alimentary canal consists first of a buccal spear (PI. I, fig. 4) 10 to 15 yp x 250 , ke long (usually about 12 y), a chitinous Fic. 1.—Heterodera radicicola, Halfgrown oOTgan, pointed at the anterior end and female (?) individual shortly before the with three small knobs at the posterior final molt: a, Anterior end; b, spear; c, E : ° esophagus: d, esophageal bulb; e, nerve extremity and pierced its whole length fe eee Sede ean: by a fine canal. Connected with the j, beginning of reproductive organs; k, basal knobs are retractile and exsertile anus. Magnified 250 diameters. Drawn mygcles. This spear is used by the nem- by W. E. Chambers. : = atode in boring its way out of the egg and through plant tissues, and through it the nourishment is apparently drawn, for its canal is continuous with the lumen of the remainder of the alimentary canal. This spear lies in a cavity, the buccal cavity, from which it may be exserted. At the base of the spear begins the slender esophagus, 40 to 50 » long, which expands then into the thick, muscular-walled esophageal bulb (figs. 2 and 3). This is a stout, muscular body, often nearly spherical, but more often a little longer 217 THE CAUSAL PARASITE. 29 than broad, about 10 by 7 ». The thick walls inclose a small lumen which can be expanded and contracted by the muscular action, thus acting in the manner of a pump in connection with the esophagus and spear (fig. 3). The expansion and contraction of the bulb are often synchronous with motions of the spear. Immediately behind the bulb the alimentary canal is rather narrow for a very short distance and then widens out rather abruptly into the comparatively thick-walled di- gestive portion which fills the body e x 700 Fic. 3.—Larva of Heterodera radicicolz: a, An- terior end; b, c, and e, spear; d, buccal cavity; f, esophagus; g and A, outer and inner por- tions, respectively, of esophageal bulb; i, nerve ring; j,excretory pore; k and J, lumen and thick wall, respectively, of alimentary canal; m, fat globule (?); n, anus; 0, pos- terior extremity. Magnified 700 diameters. Drawn by W. E. Chambers. ke O x 700 Fic. 2.—Anterior portion of the same nematode shown in figure 1: a, Anterior end; band c¢, free and inclosed portions, respectively, of spear; d, esophagus; e, outer wall, and, f, central portion of esophageal bulb; g, nerve ring; h, second bulb; i, thickened wall of alimentary canal; j, excretory pore; k, gland. Magnified 700 diameters. Drawn by W. E. Chambers. cavity and continues unchanged to a point shortly anterior to the anus. The anterior part of this digestive por- tion is not clearly marked off as a second bulb, as is the case in some species of Tylenchus. Immediately behind the esophageal bulb, surrounding the short, narrow portion of the canal, can be seen occasionally the nerve ring. About 25 to 40 anterior to the anus the walls begin to become thicker and the canal tapers, the anal opening itself being rather small. 217 30 ROOT-KNOT AND ITS CONTROL. Except anterior to the digestive portion of the alimentary canal the body cavity is small. There are no signs as yet of the repro- ductive organs, nor can the sexes be distinguished. The larvee are actively motile, but not so active as many of the free- living forms. Unlike the larve of some nematodes parasitic upon plants, for example, Tylenchus tritici,! T. dipsaci,? and a species of Aphelenchus discovered by Dorsett * on the violet and studied by the writer, the larve of Heterodera radicicola are not very resistant to unfavorable conditions. The other nematodes mentioned are unin- jured by desiccation for long periods, by cold, many acids, ete. Thus, the wheat nematode has been revived after having been left dry for 27 years. The Aphelenchus referred to remained alive in kerosene emulsion for two days in contact with a drop of kerosene. Osmic- acid fixatives killed it but slowly, as was true of chromic acid, mer- curic chlorid, and other strong poisons. On the other hand, the larvee of Heterodera radicicola, although able to remain alive in water for a few days, soon die and decay, although damp or wet soil, pro- vided the air supply is good, is favorable to their existence. Drying out is usually fatal to them in a comparatively short time. The larve of the root-knot nematode are able to remain alive in the soil for months without entering upon a parasitic existence. The writer has been unable, however, to find any evidence that they take any nourishment from the soil; at least they undergo no development until they enter the roots of some plant, for if the soil be kept free from vegetation for two years they all die. Even one year without food is sufficient to kill large numbers of them. In the normal course of development the larve, having encoun- tered a root, seek its growing point and batter their way into it by the aid of the buccal spear (PI. I, fig. 17). They then take up a position entirely within the root and parallel to its longitudinal axis, the anterior end pointing away from the root tip. This position may be in the plerome, or perhaps as frequently, if not more often, in the periblem. In the former case the nematode lies within the central cylinder as the root develops, in the latter case in the cortex. In either case the anterior end of the nematode is usually in close con- nection with the cells surrounding the conductive tissues. In the case of larvee which hatch from eggs produced within the root, some bore their way out into the surrounding soil and enter new roots, as described above, while others burrow along in the tissues of the root and settle down, usually in the fleshy cortex. Thus an old nematode gall will contain nematodes in all stages of development and at a 1 Davaine, 1857. Miinter, 1866. Needham, 1745, 1775. Baker, 1753. 2 Ritzema Bos, 1892. 3 Dorsett, 1899. 217 THE CAUSAL PARASITE. Sul depth below the surface of the root of even 5 or more centimeters. The latter has been observed by the writer in roots of sweet es (Ipomoea batatas) at Miami, Fla. Within the tissues the ee becomes fixed in position and remains quiet except for occasional movements of the spear and esophageal bulb. Whether all the nourishment is taken through the hollow spear or some is absorbed directly through the skin was not deter- mined. It seems probable, however, that the former is the case, especially in view of the fact that the female occasionally bursts the surrounding tissues of -the root, so that she lies outside the latter except for the anterior portion, which remains buried in the tissues. Growth begins almost immediately. This is mainly, however, in thickness and only slightly in length (Pl. I, figs. 5, 6, 7, and 8). By the time a gain of 10 per cent in length has taken place the thickness has increased five to ten fold. This increase in thickness is confined to the region anterior to the anal opening and in the main posterior to the esophageal bulb. The alimentary canal posterior to the bulb becomes greatly enlarged. In a week or ten days the larve of both sexes are spindle shaped. By the end of the fifteenth to twentieth day the diameter is about a fourth of the length and the differentiation of the sexes becomes apparent (PI. I, figs. 9 and 13). According to Stone and Smith‘! the female nematode sheds her skin four or five times during the course of development, the first time just before leaving the egg and the other two or three times before the final molt, when she becomes sexually mature. The writer has been unable to confirm this statement. In none of the specimens examined was any sign of shedding the skin apparent on leaving the egg, although on this point the evidence is slight, as special attention was not given to it. On the other hand, no trace of old skins could be found sur- rounding the developing larve within the galls up to the time of dif- ferentiation of the sexes. It seems possible that the investigators referred to may have been misled by the fact that an injured nematode sometimes secretes a mew cuticle underneath the old or on account of the circumstance that the molting may commence at one point long before it is visible elsewhere. If these extra molts do actually occur it seems strange that no signs are to be found of the cast-off skins around the nematode. The writer’s observations lead him to the following conclusions: The sexes are alike (externally at least) up to about the fifteenth day, or sometimes longer. Then a new skin becomes visible under- neath the old, from which it becomes separated at various points. In the female the most marked change is that of the shape of the posterior end of the body, which no longer possesses the tail it had 1 Stone and Smith, 1898, p. 22. 91294°—Bul. 217—11——3 32 ROOT-KNOT AND ITS CONTROL. before the new skin was formed. At first the remnants of the old skin are visible as an empty skin attached to the rounded posterior portion of the nematode (PI. I, fig. 9), but soon the growth of the latter obliterates the cavity left and all signs of it disappear. The anus, which before this time occupied a median ventral position some distance anterior to the tip of the tail, now becomes terminal, and immediately ventral to it but also occupying a position almost ter- minal on the rounded posterior portion appears the prominent genital opening, a horizontal opening with two rather thick and prominent lips (Pl. I, fig. 10). The anterior portion has undergone but little change. Apparently fertilization must take place at about this time, for soon the external genitalia become so modified that this would become impossible. The lips become smaller, the opening less prominent, and eggs begin to develop. Up to the last molt the larve of both sexes are alike, at least ex- ternally. The writer’s very numerous observations do not allow him to confirm the statement of Atkinson ' that the female can be distinguished before this period by the lack of a pointed tail, that of the male being pointed. In all the writer’s observations, as pre- viously described, the larve are indistinguishable until the last molt. Then the still small but sexually mature female may be seen, without a tail, in the old larval skin which has a tail. ADULT FEMALE. The mature female rapidly increases in thickness, becoming eventually flask shaped to pear shaped with a length of 400 to 1,300 » and a thickness at the point of greatest diameter of 270 to 500 z, or even 750 (Pl. I, fig. 12). The average of many measurements is about 800 » for the total length, 500 » at the point of greatest diam- eter, the length of the less enlarged anterior portion being 240 y and its diameter just before the region of great thickening begins 150 4. This not greatly enlarged anterior pomaan usually extends to a little posterior to the bulb. The body enlarges abruptly, this posterior portion being approximately spherical. Up to the last molt the spear of the female retains the dimensions and shape it had in the larva. As is characteristic of all spear- bearing nematodes, the old spear is shed with the cuticle at the time of molting, a new spear being formed in its place. This new spear is usually smaller both in length and thickness than the larval spear, and the knobs at its base are less prominent. It is usually 10 to 12 4 long as against 12 to 15 » (rarely 10 »), characteristic of the larva. 1 Atkinson, 1889. 217 THE CAUSAL PARASITE. 33 The fully mature egg-laying female is of a glistening pearly white color. The enlarged posterior portion is smooth and shows no markings, except that the internal organs are visible where they approach the surface. The comparatively little enlarged anterior portion shows faintly the transverse cuticular markings so charac- teristic of the mature male. - The bulk of the body of the sexually mature but not yet egg- laying female is occupied by the enormously dilated alimentary canal (Pl. I, fig. 11). The anus is a small round terminal opening, while the genital opening is a transverse slit slightly ventral to the anus and bordered by two more or less well-marked lips. This opens into a short, thick-walled vagina about 16 to 20 in diameter (including the walls). At its upper end it is abruptly contracted into a tube 8 to 10 » in diameter, which soon divides into two tubes, the uteri. These are at first slender but slightly coiled tubes, leading forward (usually lateroventrally) and gradually increasing in diameter. Just before the ovary is reached each uterus expands into a spherical portion, about 16 ~ in diameter, apparently the receptaculum seminis. Above this lie the cylindrical ovaries filled with the rudimentary eggs in the form of a sort of parenchyma. At this time the whole reproductive system if straightened out would not be more than 300 to 400 » long. After fertilization the uteri undergo a most remarkable elonga- tion and become very much coiled and tangled as they become filled with the fertilized ova. Although the body of the nematode increases rapidly in thickness, the increased space thus afforded is not sufficient, the alimentary canal becomes pushed to one side, and much of the space originally occupied by it is occupied by the uteri. Egg laying had already begun, in the earliest cases observed by the writer, 29 days after the seed of the host plant (Pisum sativum, the garden pea) in these experiments was planted in soil known to be infested with the nematodes. Since germination of the seed is not immediate it is probably safe to assert that during warm weather the period from the time the larva enters the root untilit begins egg laying is not over 25 days. This is somewhat longer during cooler weather, i. e., in the early spring and in autumn. In most cases the greater part of the eggs are laid in an unseg- mented condition. However, if the nematode is buried deeply in the tissues so that their pressure impedes egg laying, the eggs may develop and the larve escape still within the body of the mother, so that the latter may be viviparous. The last few eggs often develop in a similar manner, the nematode having evidently become so weak that she could not deposit them before they underwent development. 217 34 ROOT-KNOT AND ITS CONTROL. MALE. The development of the male after the larval stage differs greatly from that of the female. Within the old larval cuticle a new cuticle is formed. The nematode pulls itself away from the old skin, remain- ing inclosed by it, however. The tail is rounded here, too, but the anus is ventral instead of terminal. The whole body now elongates very rapidly, becoming correspondingly slender (PI. I, figs. 13 and 14). This necessitates a coiling in order still to remain within the old skin, until it is coiled two or three times. When this development is com- plete (PI. I, fig. 15) it breaks its way out of the old cuticle, which has retained its larval shape, and passes through the tissues and probably even outside of the root in search of a female. Just prior to leaving the old larval skin after undergoing this metamorphosis the nematode does not molt again, as some assert. The mature male differs greatly in many particulars from its appear- ance just previous to the last molt. The form is about like that of the larva on emerging from the egg, i. e., long and slender, differing, however, in the greater size and in the short, rounded tail. The length is usually 1,200 to 1,500 y, the thickness 30 to 36 4. The tail is short and rounded, not tapering, the distance from the anal open- ing to the posterior end of the body being not more than 13 to 18 4. The cuticle over the whole body is very distinctly marked with trans- verse rings extending entirely around the body and 2 to 2.5 » apart (shown in section in PI. I, fig. 16). Except in profile it is only the furrows between the projecting segments of cuticle that are visible. These cuticular rings, which are also visible on the anterior portion of the mature female, are not visible, at least at ordinary magnifica- tion, in the larve. The alimentary canal is essentially as in the young larva. The spear, however, deserves special notice. It is larger than in the larval stage or than in the mature female, being usually about 24 » in length (rarely as short as 18 » or as long as 28). The knobs at its base are prominent. Above the knobs the sides are parallel for about half way and then taper to the finely pointed tip. The canal through the spear is rather distinct. The body wall is about 1.5 y» thick. However, at the truncate anterior end it is between 5 and 6 4 thick. The anterior 2.5 » of this is a sort of hood, or cap, set off from the rest of the body by a sharp furrow. Lying in the terminal body wall, well below this hood and projecting but slightly into it, is a series of six radiating perforated lamelle (apparently chitinous in nature), narrow at their anterior ends and broad basally. Viewed from the side they are approximately right triangles, the hypotenuse being somewhat wavy. The bases of the lamelle radiate from a 217 THE CAUSAL PARASITR. 35 common center, and the upright legs of the triangle surround a canal through which the spear passes. The bases are united into a small ring just around this canal and another ring unites the outer ends of the basal legs (Pl. I, fig. 16). Looked at from the anterior or pos- terior direction this apparatus resembles a wheel with six spokes. Distinct muscle strands run from the rim of this wheel to the knobs of the spear, as well as to the point where it begins to taper. It is probable that this peculiar organ is to help support and guide the spear as the male is battering his way through the tissues. A similar apparatus is present in Heterodera schachtii, the sugar-beet nematode. It was imperfectly described by Strubell,' but the writer’s observa- tion shows it to be essentially the same as in the root-knot nematode. It has also been reported, but not correctly described, for a Tylenchus species. The reproductive organs of the male consist in all cases examined by the writer of a single testis, a tube blind at the anterior end and running parallel to the alimentary canal, into which it opens just before the anal opening is reached. Atkinson reports that there are two of these reproductive organs, as is the case with some other nematodes. In all the specimens examined by the writer, however, including specimens from Indiana, South Carolina, and Florida, using the oil immersion lens and viewing the nematodes from different sides, there was not the slightest evidence of a second testis. Cobb ? also mentions its presence, and as both he and Atkinson are accurate observers it must be that sometimes this occurs. In fact, Atkinson himself later found specimens in which the testis was single. Accord- ing to the writer’s own observation the right testis is the one that is missing, as the one present is placed somewhat asymmetrically, lying nearly in the left half of the body. Lying on either side of the posterior portion of the alimentary canal and with their points entering the cloacal chamber are two peculiar, somewhat sickle-shaped bodies, the spicules. These are curved bodies, tapering toward the posterior end, about 35 long, measured on the chord connecting the two ends. No accessory piece is present, although a thickening near the apical portion may represent one fused with the spicules. These spicules are of use only during the sexual process. The excretory canal is plainly visible in the left lateral line, open- ing ventrally in the median line 160 to 170 y» from the anterior end of the body. It seems probable that the mature males take little or no food and that they perish after having performed their function. The reason for this supposition is the fact that one often finds still actively 1 Strubell, 1888. 2 Cobb, 1902. 3 Atkinson, 1889; see also Atkinson, 1896. 217 86 ROOT-KNOT AND ITS CONTROL. moving males in which the alimentary canal posterior to the bulb, or even including it, has entirely disintegrated, leaving the body cavity filled with a granular disorganized mass except for the long testis, which extends nearly to the esophageal bulb. The large buccal spear with its complicated guiding apparatus is doubtless to enable the animal to batter its way through the root tissues in its search for the female, as a much smaller spear serves the female for obtaining the necessary food. OVERWINTERING. The stage in which this nematode overwinters was made the object of considerable study. In the galls on annual plants examined in November it was found that in almost all cases the mature or partly developed nematodes, as well as the eggs, were dead, in many cases being filled with fungous threads. Larve, however, alive and actively motile, were found in abundance in and around the galls. It is probable, therefore, that it is in the larval stage that the nema- todes from annual plants pass the winter, probably descending into the lower levels of the soil to avoid the cold. This latter point, however, was not determined. In cases where the death of the top of the plant had caused the death of the roots, the nematodes in the roots soon died also. In roots of perennial plants, for example, European grape, fig, etc., the writer has repeatedly found lving female nematodes in nearly or quite complete development at various periods in the winter and early spring, showing that in such roots the nematodes may survive not only in the larval stage, as previously described, but also as mature females ready to begin egg laying as soon as the weather becomes favorable. COMPARISON WITH HETERODERA SCHACHTII. In view of the fact that some authors! have questioned the correct- ness of keeping separate the two species Heterodera schachtu, the sugar-beet nematode, and H. radicicola, the cause of root-knot, it will be well to give briefly an account of the points of difference, especially since the writer has found the former to be a serious pest at several points in California and Utah, while the latter has been found as a serious sugar-beet pest at some other points. In tabular form the main differences are easy to point out. 1 Stone and Smith, 1898; Atkinson, 1896. 217 THE CAUSAL PARASITE. 37 TaBLE II.—Differences between Heterodera schachtii and H. radicicola. Points. Heterodera schachtii. Effect on host........... No galls. Location of mature fe- | External, antiee end only within male. tissues of root. Shape of female, external | Mostly lemon shaped, dull and flaky appearance, ete. in appearance, no trace of transverse Heterodera radicicola. Produces galls on roots. Usually entirely within tissues of root, more rarely the posterior portion, very rarely nearly the whole body external. Pear or flask shaped, glistening and pearly white, tramsverse rings of rings. er often visible on anterior por- Bepess:.. 252342250555 - Part deposited outside body, but most | All but the last few deposited outside developing within it. the body. LOLA, ee ee ee uccal spear about 25 » (Pl. I, figs. 18 | Buccal spear 10 to 15 », mostly 12 to 15 x and 19). (Pl. I, figs. 3 and 4). . Mature male............ Buccal spear about 30 » (according to | Buccal spear mostly about 24 p. Strubell, 1888). That these nematodes are not the same is readily seen when they occur on the sugar beet. The one causes no conspicuous galls while the other makes the galls so characteristic of root-knot (PI. IT, fig. 1). Both are very destructive pests of this host, and there is not much choice as to which is the more harmful. Another difference not mentioned above is that H. schachtui, perhaps by virtue of its more powerful spear, is able to thrive and spread in stiffer soils than does H. radicicola. In Plate I the figures for the larve of Heterodera radicicola (figs. 3 and 4) and H. schachtia (figs. 18 and 19) are drawn to the same scale, respectively. The difference between the two species was emphasized in tabular form by Voigt in 1890. METHODS OF SPREAD. The larva of Heterodera radicicola is capable of active movement in the soil, and in this manner doubtless the disease is slowly spread. From some experiments made by Frank‘ he estimated the rate of progress at about 3 cm. per week. This would amount, during the warm weather, in which infection occurs, say May 1 to September 15, to about 75 cm., or about 30 inches. These figures are probably far too low. However, it is not through their own efforts that these nematodes are mainly spread. There are many means of transporta- tion at their disposal. A very frequent one is running water. Thus, a field previously free from the pest sometimes shows its presence in those spots where surface water at a time of heavy rains has deposited a lot of soil from an infested field lying higher up. In this way the pest has been carried from infested fields even to uncultivated woods, as observed by the writer at one place. It has been suggested that heavy: winds carrying large quantities of soil from one field to another may also transfer the nematodes, but in view of their sus- ceptibility to injury by drying, this seems little likely. Especially is 1 Frank, 1885. 217 388 ROOT-KNOT AND ITS CONTROL, this unlikely since the larve shun dry soil, and so would not be present in that part of the soil which is dry enough to be transported by the wind. More effective as means of transportation are the hoofs of animals, wheels of vehicles, farm implements, and men’s boots. Itis difficult to see how it would be possible to avoid conveying living nematode larve from one field to another on farm implements if they are left, as is too often the case, uncleaned on being trans- ferred from one field to the next. Thus, a wagon and horses going from one field to another would, if the soil were at all damp, carry some of the damp earth, probably containing nematode larve, with them. The foregoing explains the spread of nematodes after they have once been introduced into a locality. The introduction of nematodes into a new locality, however, must have some other manner of accom- plishment. This seems to be in most cases along with nursery stock. Thus, the writer found that in parts of Texas the nematode appeared first in the soil near fig and mulberry trees obtained from farther east, which were noticed at the time of planting, several years ago, to have knotted roots. In this way the soil near the trees became infested and thence the disease spread, as previously described, to different points in the locality. Perhaps east of the irrigated districts the fig, mulberry, and peach are responsible more than any other plants for the spread of the disease. Since the putting into effect of good nursery inspection much of this source of infection has been cut off. In the irrigated districts of Arizona and California the vine was observed in several cases to be the plant at fault. The strawberry has been observed at a few points in the East as the plant upon which the pest was introduced. It is often badly affected without showing much injury. A case has been called to the writer’s attention in which the disease was introduced into a garden in Washington, D. C., by asparagus roots from an infested field. The wide distribution of the disease in ginseng plantations is doubtless due to the setting out of small rooted plants from infested regions, as well as to the practice of some growers of packing the seed in damp earth. Should this come, as is natural, from the vicinity of the ginseng bed and this be affected by nematodes, the danger of sending nematodes along with the seeds is very great. The dirt used for packing is naturally thrown out at the point where the seeds are planted, and thus the larve, if present, are able to enter the soil and infect the young gin- seng seedlings. Seed potatoes are also another known source of introduction of the disease.! In a personal communication Dr. N. A. 1 Lounsbury (1904) regards the potato as perhaps the chief source of introduction and spread of this dis- ease in South Africa. 217 THE CAUSAL PARASITE. 39 Cobb expresses the same opinion based on his observations in New South Wales." For the North, where root-knot is mostly confined to greenhouses and hotbeds and their vicinity, perhaps one of the chief sources of infection is the soil that is thrown out of these beds at the end of the season. This soil, if infested, will spread the disease in the imme- diate vicinity, especially if it be put near some manure pile or compost heap which keeps the ground damp and warm during the winter. EFFECT ON THE HOST. The effect upon the root of the presence within it of the young nematode is usually the hypertrophy of some of the tissues. The parenchyma cells become abnormally large and multinucleate,? sometimes only a few, at other times a great many cells being involved in this hypertrophy. This abnormal enlargement of the cells leads to a displacement of the various tissue elements, so that the tracheary cells and vessels become separated and also show lateral displace- ment and often much distortion. Often in bad cases individual cells of a tracheary nature will occur entirely separated from others of the same kind. The amount of hypertrophic enlargement of the root depends upon the host on the one hand and upon the number of nematodes entering the root in the same vicinity on the other. In some roots the swelling is barely noticeable and is so small that as the female nematode enlarges she eventually is inclosed in the root only by the narrow anterior third of the body, the remainder being entirely external, in this particular showing great similarity to the sugar-beet nematode, whose galls are always of this nature. More often, however, the hypertrophy is so pronounced that the mature female is entirely concealed or reaches the surface only at the extreme posterior portion of the body. If many nematodes are present in the same general region of a susceptible root, the gall may be many times the normal size of the root (PI. II, fig. 2). These galls are at first of soft tissues, but in some woody plants, the European elm, for example, some of the hypertrophied cells become lignified, inclosing the female nematode in a woody prison from which in all probability the larve would be unable to escape should egg laying continue after the lignification has begun. The structure of such a gall is like that of the burls that often occur on various trees. A very frequent phenomenon, but one that is by no means uni- versal or characteristic of any one group of plants, is the formation of numerous lateral rootlets above the gall. This is doubtless due 1 The writer’s attention has been called to the fact that in certain of the irrigated districts of the West this nematode has become a very serious potato trouble. On one occasion several carloads of potatoes were rejected on account of being infested with it. 2 Tischler, 1902. 217 40 ROOT-KNOT AND ITS CONTROL. to the disturbed and to a large extent interrupted water supply and to the accumulation above the gall of food substances which would normally pass on to the root tip. They accordingly are made . use of in the formation of lateral roots at that point. It is probably not different in its nature from the adventitious root formation in cot- ton and other plants just above the point of entry of the wilt fungus ( Neocosmospora vasinfecta)* or, in fact, from that oecurring when the end of a root is cut off or mechanically injured. The shape or size of the gall does not seem to depend upon the place the plant occupies in the current schemes of classification. The statement of Frank ? that the galls of the dicotyledons are mostly of the round, tuberlike type, with lateral rootlets, while those of the monocoty- ledons are mostly spindle shaped, without lateral rootlets, is not confirmed by the writer’s observations. Galls of both types may be found on the same plant (PI. III, figs. 1 and 2) and appear to owe their differences to the number of nematodes entering at a given point, to the age and rapidity of growth of the root, and perhaps to other causes. On both the beet and the radish, as well as on many other plants, both types of galls and all gradations between may be found. Entrance to the plant by the larve is not confined to root tips or to passage from galls to the adjacent healthy tissues, although these are the usual ways by which a nematode reaches the point where it undergoes its subsequent development. Nematodes are also able to bore from the outside directly into the tender tissues of other parts of the roots, and even into stems. Thus, not only are the roots of potatoes attacked but even the tubers, while some- times the prostrate stems of tomato plants as well as those buried beneath the ground in setting out the young plants are badly knotted. Indeed, Sefior Romulo Escobar, of the Mexican Ministry of Agriculture, informs the writer by letter that in the State of Nuevo Leon the roots, stems, leaves, and even fruits of the watermelon are attacked when they are in contact with the ground. This is excep- tional, however, and is possible only where the nematodes are very abundant and when the surface of the soil is constantly moist, so that they are in its uppermost layers. Through the kindness of Mr. W. K. Winterhalter, then consulting agriculturist of the American Beet-Sugar Co., at Rocky Ford, Colo., analyses were made of sugar beets badly affected with root-knot and of healthy beets from the same field. Strange to say, in six samples each of healthy and diseased beets the average sugar content differed less than one-fifth of 1 per cent of the total weight of the beet, while the percentage of purity was equally as close in the two lots. In these points there also seems to be a marked dis- 1 Orton, 1902, p. 10, fig. 1. 3 Frank, 1885. 217 a CONDITIONS FAVORING ROOT-KNOT. 41 tinction between the root-knot nematode and the true sugar-beet nematode (Heterodera schachtvi), for the latter’s presence not only reduces the size of the affected beets, but also greatly reduces their sugar content and usually lowers also the purity. The greatest depth at which Frank observed nematode galls was 33 centimeters th3 inches). On the other hand, the writer finds that they solf more than a yard below the surface of the soil. To be sure, tWe@se are only scattering galls, for the great major- ity of the nematode galls occur in the first foot of the soil. Indeed, in practical culture it has been found that if trees can be forced to root extensively at a depth of 16 inches or more they suffer but little from root-knot , CONDITIONS FAVORING ROOT-KNOT. SOIL. Root-knot is essentially a disease of light soils. Wherever the soil is sandy or contains a fairly large proportion of sand, other con- ditions being favorable, the root-knot nematode may be expected to thrive when once introduced. In heavy soils, on the other hand, the disease seems never to be serious. In some of the writer’s experiments affected plants were planted in pots of stiff clay soils, and not only was it almost impossible to obtain infection of sus- ceptible plants placed in close proximity in the same pots, but even on the diseased plants the new roots remained free from the trouble. Similar experiences have been reported to the writer from various parts of the country where diseased trees were set out in stiff soil and after a few years seemed to be entirely free from the trouble. Contradictory statements sometimes find their way into print, but they are explicable in most cases when one understands the great popular confusion in the use of the words ‘“‘heavy,” “stiff,’’ and “light’’ as applied to soils. Thus, in parts of Florida and South Carolina a very sandy, yellow soil containing only enough clay to hold it together while moist, is called “clay” or “heavy soil.” It is clayey, to be sure, compared with some of the soils thereabouts, for sometimes the latter are almost pure sand. ‘Light’ and “heavy” in the sense used in this bulletin have reference to those soils containing, respectively, little and much clay. Soils that dry out rather quickly, that do not cake hard on drying, and that are easily crumbled to a fine granular mass are favorable to these nema- todes, while the reverse is the case for the difficultly permeable, hard-caking, clayey soils. This applies only to the root-knot nema- todes, as the writer’s investigations have not gone into this point with reference to other sorts. It is known that the sugar-beet nematode will thrive in some of the heavier as well as in light soils. 217 42 ROOT-KNOT AND ITS CONTROL, MOISTURE. A certain degree of moisture is necessary for the maintenance of the life of the nematode in the soil. Experiments by the writer, Frank,} and others have shown that the larve of the root-knot nematode, unlike those of many other nematodes, are das d by being dried in the laboratory. Observations by the wil tieifew Mexico, Ari- zona, and California confirm this abundantly, torn those communi- ties the root-knot is practically confined to the irrigated land. This does not mean that the soil must be wet, for that is not necessary. The soil, however, must have sufficient moisture in it to be properly called a moist soil, though not enough to fill the air spaces and inter- fere with proper aeration. Thus, we have reports from South Africa,? Argentina,’ and Chile * which state that the nematodes grow only in wet soils. This, in the light of conditions existing in America, evi- dently means not what we would call wet, but merely moist, in the eastern and southern part of the United States, but what many people in irrigated districts would not hesitate to call wet in contradistinc- tion to the dry, unirrigated soils. Prof. P. H. Rolfs,> Dr. N. A. Cobb, and others report experiments which would seem to prove that dry- ing of nematode-containing soil does not entirely kill out the Hetero- dera radicicola. This will be discussed more in detail later. On the other hand, soils that are water-logged for a considerable part of each year are usually free from the trouble. Some observa- tions on the effects of floods on nematodes led the writer to believe that flooding for a few days would destroy them, but field experiments in Arizona and California showed that keeping the soil submerged for five days was not sufficient to kill out the nematodes, at least not those inclosed within the root galls of the trees and vines growing in the fields. Yet it is certain that very wet soils are free where this is long continued, and long periods of flooding kill out the nematodes. Thus, in the Everglades of southern Florida there occur islands, parts of which are never flooded and parts of which are out of the water ordinarily, but submerged for two to six months of the year. Truck growers occupy some of these islands and find that the root-knot nematode is abundant above the high-water level—i. e., where the land is never flooded, but absent in the zone that is flooded every year. TEMPERATURE. As long as the soil is not too dry, the higher the temperature the more actively the nematodes seem to develop. On the other hand, they seem to become practically inactive when the soil temperature falls below 50° F. Yet they are capable of remaining alive when 1 Frank, 1885. 2 Lounsbury, 1904. 8 Huergo, 1902, 1906. 4 Lavergne, 1901. 6 Rolfs, 1894. 217 CONDITIONS FAVORING ROOT-KNOT. 43 exposed to great cold. The writer saw root-knot abundant on gin- seng in a slat shed in Menominee, Mich., where the soil a year or so before froze to a depth of more than 3 feet and where outside the shed water pipes 6 feet beneath the surface were frozen, so the writer was informed. In spite of this cold the nematode injuries were bad the next year. In York, Nebr., where the temperature goes below zero every year and sometimes reaches nearly or quite to —30° F., this nematode survived the winter in peony roots which remained out of doors without protection. In New York State ginseng and alfalfa are both more or less affected with root-knot, while in West Virginia, along the Ohio River, clover is badly atfected. It thus becomes apparent that cold alone does not destroy the pest in the soil. To be sure, Bailey placed soil containing root-knot nematodes in boxes and set some of the boxes out of doors through the winter. In the spring the boxes kept indoors still had living nematodes, as shown by gall formations upon plants grown from seeds sown there, while the boxes left out of doors were free from nematodes. It seems probable that the soil in this case dried out in the freezing process sufficiently to kill the nematodes. Ordinarily, however, the frozen soil remains in connection with soil moisture below, and so the drying out and consequent destruction of nematodes does not occur. The root-knot nematode does not become active in the soil and begin to penetrate the roots of susceptible plants until the soil begins to be warm. In the tropical and subtropical regions plants are sub- ject to attack the year around, but the farther north one passes the longer is the winter period of comparative immunity from injury by this pest. Thus, in Miami, Fla., there is no dormant period for the nematode. In northern Florida, however, crops planted in the latter part of November or in December show comparatively little injury, nor does the injury begin to be severe until the middle of February or early in March. On the other hand, plants sown in October are in- fected before the soil becomes cool and are badly injured, the nema- todes continuing to develop and spread within the tissues when it is too cool for them to spread outside through the soil. At Monetta,S. C., about half way between Columbia and Augusta, Ga., in the writer’s experiments no infection by nematodes could be obtained before the middle of April, while it was the middle of May before they became really active. By the end of September or the middle of October their activity had begun to decline. Frank ? assumed that the chief period of infection was in the spring. He was in error in this statement, for the writer’s experiments show that the nematodes are more active in midsummer and that infec- ‘ Bailey, 1892, pp. 157-158. 3 Frank, 1885. 217 44 ROOT-KNOT AND ITS CONTROL. tions occur more freely the warmer the weather, except where lack of rain permits the soil to dry out, in which case both plants and nematodes cease to thrive. CONTROL OF ROOT-KNOT. The problem of the control of root-knot is one that varies much according to the place infested, the kind of plants grown, the methods of culture followed, etc. We may distinguish between small, inten- sively cultivated lots of soil, such as we find in greenhouses, hotbeds, and seed beds, and field culture. Each group may be subdivided in accordance with the answer to the question whether the crops are annual or long lived. For the first great division, owing to the value of the crops raised and the amount of capital invested, methods of combating a disease may be used that would be barred from field crops or other crops on larger areas of land, because the expense would not be justified in view of the comparatively low earning power of the land. Furthermore, the actual monetary loss to the crop due to a given disease may be far greater in the restricted areas of intensive culture than in large fields where each plant is of relatively less value. So, for example, root-knot may affect a field of cowpeas and actually reduce the crop one-half, but unless the field were very large that might not equal the loss sustained by a grower of cucumbers, lettuce, or tomatoes whose whole greenhouse crop has been totally destroyed by the same pest. GREENHOUSES, SEED BEDS, ETC. LIVE STEAM. Probably the most satisfactory method for destroying the root- knot in greenhouses and seed beds is the use of live steam under considerable pressure. This has been advocated by various persons, viz, May, Galloway, Selby, and Rudd,' but it was as a result of care- ful experiments by Stone and Smith * that it became generally used. The method recommended by them is a modification of that recom- mended by Galloway and others. The scheme is essentially as fol- lows: At the bottom of the bench or bed are laid either iron pipes perforated with -inch holes every few inches or drain tiles. Live steam is passed sie these and escaping from the holes of the iron pipes or between the ends of adjacent tiles heats the soil to such a degree that all animals and most plants (except, of course, bacterial spores) are killed. The pipes must be placed at intervals short enough to permit the spaces between the rows of piping to be thoroughly per- meated by the steam. This distance varies with the soil, but 12 1 May, 1896; Galloway, 1897; Rudd, 1893; Selby, 1896. 2 Stone and Smith, 1898. 217 CONTROL OF ROOT-KNOT. 45 inches is close enough for all general purposes, and even 2 feet is not too far in deep beds if the sterilization is kept up long enough. The bed should be covered with straw, boards, sacking, or something of the kind to permit the upper layer of soil to become heated through. The pipes or tiles in the soil should be arranged lengthwise in the beds, with the steam inlet in a crosspiece of piping running across the bed, from which the longitudinal rows take their origin. A similar crosspiece at the other end may be used, but is not absolutely neces- sary. There should be no open ends of pipes or tiles; otherwise all the steam will escape out of these and not through the cracks or small holes. Depending upon the pressure of steam used, the time neces- sary for sterilization will vary from half an hour to even two hours when the pressure is poor. A method often recommended to determine whether the steam has passed long enough, and one that has considerable merit, is to bury raw potatoes at the surface of the soil underneath the covering of straw, boards, or sacking. When all these potatoes are found to be cooked the steam can safely be turned off. Stone and Smith recom- mend the use of a special boiler so that steam at fairly high pressure can be used, not under 40 pounds per square inch, preferably more. Even 80 to 100 pounds pressure is not too high if obtainable, as it shortens the time necessary and also prevents the soil from becoming as wet as with lower pressure. . Not only are all nematodes killed by this treatment, but also all insects and other noxious animals, as well as all fungi and their spores. Many bacteria are killed, too, but not all of their spores, the survival of the latter being desirable in view of what we know of the value of soil bacteria. This method has some disadvantages. Thus, it can not be used for beds occupied by living plants. Furthermore, care must be taken on the one hand not to leave the soil soggy and on the other not to dry it out too much. The latter is, however, a much less seri- ous matter than the former. FRESH SOIL. For greenhouses, cold frames, seed beds, etc., where a steam-heating plant is lacking and where it would not pay to incur the expense of installing a boiler for the purpose of using it for soil sterilization, the desired results can be obtained by the use of fresh soil each year. This should be taken from some place in the woods or from a field where the nematode is known not to occur. The old soil should be placed where it can do no harm in the way of spreading the disease. If it can be allowed to become perfectly dry for some weeks before taking it out, the danger from the old soil is greatly reduced. The 217 46 ROOT-KNOT AND ITS CONTROL. framework of the beds should be thoroughly whitewashed with strong, hot whitewash, freshly made from good quicklime, or it may be painted with formaldehyde or some other disinfectant of this nature. This is to kill all larve or eggs that might be in the dirt adhering to the cracks. In selecting new soil it will always be well to examine the roots of susceptible plants growing where the soil is to be obtained in order to determine whether or not root-knot is present. This method has given good satisfaction where carried out in the North. It is applicable, however, only to small greenhouses that do not require much new soil. Large greenhouses can be far better taken care of by sterilizing the soil in the benches. It often happens that to obtain fresh soil is not desirable in view of the character of the soil in the vicinity. Perhaps it has taken some years to bring up the soil in the beds to the desired lightness, humus content, etc., and to have to take new soil every year would beahardship. In such cases steaming should be made use of if pos- sible. If it is not feasible, a formaldehyde solution has shown itself of considerable value. FORMALDEHYDE. The formaldehyde method consists essentially of treating the soil with a weak solution of commercial formaldehyde (or formalin). It has been found that a solution of 1 part commercial (36 to 40 per cent) formaldehyde in 100 parts water is effective against the root-knot nematode in shallow beds when applied at the rate of 1 to 14 gallons (or more in the case of very absorbent soils) to every square yard of soil surface. For deep beds the quantity must be increased. Care must be taken that all parts of the soil are reached and thoroughly wetted by the solution. Upon the thoroughness with which it is done depends largely the success of the process. After the formaldehyde solution has soaked in the soil should be thoroughly stirred, so that all parts may be exposed to the disinfectant. Before setting into the soil any plants or sowing any seeds the excess of formaldehyde must be allowed to escape by evaporation or, if necessary, be washed out by flooding the bed. The former is preferable. The writer has not found the germination of seeds interfered with when 10 days are allowed to elapse between the treatment and the sowing of the seeds, especially if the soil be allowed to become rather dry and be stirred in the mean- while. This formaldehyde treatment has been used with success at the Ohio Agricultural Experiment Station 1 in the forcing house and seed beds. It was applied primarily to prevent certain damping-off fungi from destroying the seedlings, but it was found that the nematodes were sometimes destroyed also or greatly reduced in numbers. How- 1Selby, 1906. 217 CONTROL OF ROOT-KNOT. 47 ever, as a means of combating nematodes it is not recommended by Prof. Selby. The strength of the solution used there was about 1 to 14 parts commercial formaldehyde to 400 of water, which is less than that found to be really effective against this nematode. The treatment of living plants in the greenhouse to destroy root- knot is fraught with considerable difficulty. Means that will destroy the nematodes are mostly injurious to the plants containing them. Thus, steaming or drying and freezing the soil can not be thought of, as these processes are fatal to the plants. So, too, the use of carbon bisulphid has in a similar way proved not feasible. It is still possible, however, that certain plants less susceptible to this chemical, if per- fectly dormant and rather dry, might escape without serious injury when enough of it was used to kill the nematodes present. This must be determined by experiment. Under certain conditions the use of the formaldehyde solution has been found efficacious with some kinds of roses. Many plants are killed outright by the treatment, but roses, at least some sorts, are less susceptible to injury. The first experi- ments in this line were performed in February, 1902, in the green- houses of Mr. Loosé, a florist of Alexandria, Va., under the direction of Mr. A. F. Woods,.of the Bureau of Plant Industry. The writer cooperated in so far that he examined the roots for nematodes after the experiment. The following extracts from Mr. Loosé’s report of the experiment indicate the methods used: In the early part of February a bed of Bridesmaids, 150 feet long and 3 feet wide, 4 inches soil, was thoroughly saturated, using 50 gallons of the 1 per cent mixture. The plants did not seem to suffer from the application, and one week later we were able to see young healthy roots making their appearance, while the old fibrous roots were entirely decayed. We then treated in the same manner Bride, Kaiserine, Chatanays, Nephetos, Beauty, Liberty, and Meteor with equal success as to freeing the soil of the pest. Some strong-growing varieties, however, such as Beauties, Chatanays, and Kaiser- ine, suffered and lost much of their foliage. Even some of the soft growth wilted during the sunny part of the day. My experience in this treatment is that care should be taken to harden: the plants by lower temperature and keeping the beds dry, being careful, however, to give the plant a good watering 12 hours before apply- ing the mixture. * * * The cut of roses on February 10, at the time when we applied the remedy, had dwindled down to 250 a day. It remained practically sta- tionary during the four following weeks. We were able, however, to notice that the foliage was regaining its normal color and the plants were starting strong growths. By April 1 our cut had increased to 500 daily, mostly prime stock, and by the middle of April it had resumed its normal cut of 1,000. As a matter of experiment we left a few plants untreated at the ends of some of the benches, and to-day, May 10, they are practically worthless, showing effectually that the spring weather had nothing to do with the improvement. The roots of the un- treated plants looked like a ball of fern roots used for orchid potting, full of galls and matted, plants making a weakly growth, foliage pale, and flowers insignificant. On the contrary, the plants treated last February have healthy strong roots, making fine growth and the foliage of the very best color. 91294°—Bul. 217—11—_4 48 ROOT-KNOT AND ITS CONTROL. The mixture was applied with the hose connected to a force pump at the rate of 4 pounds of formaldehyde to 50 gallons of water, the treating of 15,000 plants requiring 200 pounds of formalin, worth about 18 cents a pound, making the treatment quite inexpensive considering the result. Since this experiment this method has been tried in a number of places and with success where the proper precautions were taken. Doubtless other plants might be treated similarly, but the method should be tried with caution, even for roses, until it is ascertained that the plants will not be killed. MISCELLANEOUS. Plants for which the formaldehyde treatment can not be used can often be benefited by the following treatment: Remove them from the soil, wash the roots clean, and cut away every diseased root, burning them. Top the plant to correspond with the amount removed from the roots and plant in nematode-free soil. Such severe treatment is too injurious to some plants, and about all that can be done then is to give them plenty of well-aerated soil with an abundance of fertilizer, so as to stimulate root growth to more than counterbalance the roots that are reduced in value by the entry of the nematodes into them. It is possible that by transplanting diseased plants to stiff clay soil the number of nematodes will be so reduced that a subsequent trans- plantation to more suitable soil will find them free from the disease. On purchasing rooted plants, unless they come from a place known to be free from root-knot, it will always be best to put them into a quarantine bench for several months. If at the expiration of this time they show no signs of the trouble, they can safely be removed to their permanent quarters. Of course the soil in the quarantine bed must be renewed whenever it becomes infested with the nematodes. Moderate quantities of soil can be freed from the pest by putting it at the beginning of winter in a place where it will be exposed to the cold and subject to drying out at the same time. Thus, it can be thrown upon boards in a comparatively thin layer. The boards will keep the nematodes from passing downward into the ground as the soil dries out. At the same time the boards keep the moisture from the soil beneath from passing by capillarity up into the soil from the beds. The continued drying and freezing, especially if the soil be occasionally stirred, is fairly effective in killing off the nematodes. CONTROL OF ROOT-KNOT IN THE FIELD ON PERENNIAL CROPS, The treatment of perennial crops in the field is of a greatly different nature from that of plants in the greenhouse, cold frame, or seed bed, for a process that could be applied with profit to such valuable soil as that in greenhouses, etc., might, indeed mostly does, prove too 217 CONTROL OF ROOT-KNOT. 49 expensive for ordinary use in large fields where the crop value per given area is far lower. The methods to be applied differ according to whether the land is used for annual or short-lived crops or is pos- sessed by a long-lived crop, such, for example, as fruit trees. In the former case the treatment ¢an be begun after the crop is off, while in the latter it must be of such a nature that the trees present do not receive injury. The latter problem will be discussed first. In the South the trees most generally affected seriously are the peach, fig, mulberry, and walnut, while in California and Arizona the Old World grapevine is seriously affected in addition. Many other plants are subject to great injury elsewhere, such as coffee in Brazil, Mexico, and the East Indies; papaya (Carica papaya) in Florida and the Tropics; shrubs like tea in Ceylon and India, ete. By consulting the list of plants subject to the disease it will be seen that many are woody plants and that of these a number besides those mentioned are seriously injured by the disease. CHEMICALS. Of the various treatments proposed, the use of chemicals has offered a wide field for investigation and one that is by no means thoroughly explored as yet. The more promising chemicals tested by the writer are mentioned in the following paragraphs: Carbon bisulphid—This has been used in Europe for the phyl- loxera on vine roots where the plants were dormant, without serious injury to the vine. The writer’s experiments, however, lead him to look upon it with suspicion. Many plants were very quickly killed by it and others seriously injured. Its use should not be attempted without first testing its effect upon one or two trees. These should preferably be dormant, at least not in an actively growing condition. The root hairs are killed outright, so the plant must not be where it will actively transpire until new root hairs are formed. The usual method of procedure is to make holes in the ground to a depth of several inches or a foot or more, the carbon bisulphid being poured or injected into these holes and the latter covered up with dirt before the liquid volatilizes. The fumes penetrate the soil and destroy nearly all living things. Extreme care must be used in handling this chemical, as its fumes are poisonous and exceedingly inflammable, being explosive when enough air is mixed with them. Carbon bisulphid will doubtless be of value in an orchard or grove where it is desired to replace certain trees or fill vacant places with new plants. By its use the spots where the old trees stood or where vacant places are to be filled can be thoroughly disinfected. After a week or two the trees can be set out and, the soil being free from nematodes, can make quite a start before the nematodes from the 217 50 ROOT-KNOT AND ITS CONTROL. soil outside of the disinfected patch can get to their roots. In deep sandy soil the writer found not all the nematodes destroyed by the use of 2 ounces of carbon bisulphid per square yard, but when 4 ounces were used they were exterminated. The size of the area to be treated depends upon the size and rapidity of growth of the trees to be planted, the faster they grow the smaller being the area to be treated. For the best results the chemical must be placed at a depth of several inches below the surface, the opening being firmly closed so that the vapors will have to diffuse throughout the soil. In France special forms of apparatus have been devised for this purpose in combating phylloxera. They consist of a reservoir for the liquid and a hollow rod which can be inserted to any desired depth, a measured quantity of the liquid then being forced out into the soil. In the writer’s experiments, however, use was not made of these rather expensive contrivances, but of a simple dibble consisting of a pointed piece of broomstick. Holes were made to the depth of a foot to the number of eight or nine to the square yard. The desired amount of carbon bisulphid was poured into them, each being closed at once by the foot and the earth firmly pressed down to prevent the escape of the vapors into the air. About a teaspoonful to each hole is sufficient, or about 4 ounces to the square yard. Potassium sulphocarbonate.—Potassium sulphocarbonate in the form of a solution of 1 part, by weight, to 5 parts of water to be applied in little trenches dug around the diseased trees is recommended by Gan- dara.t. According to him, 4,000 liters of the solution suffice for a hectare—i. e., about 425 gallons per acre. His experiments were with nematode-affected coffee. This treatment he reports as being success- ful, but too expensive for general use. The writer’s results, however, were not so successful. Papaya plants (Carica papaya), about 18 to 20 months old and with roots badly affected with root-knot, were used. The chemical, diluted as directed by Gandara, was applied to some trees in little ditches and to some in numerous holes about a foot deep. After it had all soaked in, the soil was watered thoroughly, as it was very dry, so that the chemical might the better soak evenly through the soil. In a day or two some of the old leaves dropped, showing that the roots had suffered some injury; but at the expiration of a few weeks the roots were found to be as badly knotted as ever, prov- ing that for the papaya, at least, this process is ineffective. The high cost of the chemical, moreover, would make its use utterly impracticable. Formaldehyde.—In view of the comparative success obtained with formaldehyde solution on roses it was tested on papaya trees out of doors. A ridge of earth was made around each tree at a distance of 1 Géndara, 1906. 217 CONTROL OF ROOT-KNOT. 51 about 5 feet, so as to retain the solution. One part of commercial formaldehyde (about 40 per cent strength) was mixed with 100 parts of water. About 25 gallons were applied to each tree—i. e., about 3 gallons to the square yard. In some cases water was applied after- wards to cause the solution to penetrate deeper; in other cases no water was added. A few of the older leaves turned yellow and dropped off a day or two after the treatment, but no further injury was noticeable. In two weeks the nematode root galls, containing living nematodes, were found to be almost as numerous as ever, although a good many of the galls on the roots nearest the surface were found to contain dead nematodes. These and other experi- ments lead the writer to believe that where the soil is rather deep and the liquids applied can drain through instead of remaining in the immediate vicinity of the roots this formaldehyde treatment is not likely to prove very effective. Calcium carbid.—The use of calcium carbid was also recom- mended by Gandara.' His instructions were to mix 4 parts of it with 1,000 parts of water. After letting it stand half an hour this milky solution is to be injected into the soil in five holes per square meter, 10 grams to a hole. Through lack of other trees suitable to test it on, papaya trees were also used in testing this method. A modification was also made in that about an ounce of the calcium carbid, without previous treatment with water, was placed in the bottom of 8-inch holes, which were promptly plugged with earth, about eight or ten holes being made to the square yard. Afterwards the soil was thoroughly watered. In this case a strong odor of acety- lene was noticeable for two days. No damage was done to the trees and the nematodes in the galls were not killed by either treatment. Other chemicals.—Various other chemicals recommended have the disadvantage that they are poisonous to living plants or too expen- sive. It is still possible, however, that some easily volatilizing liquid may be found whose vapors while fatal to the nematodes will not seriously injure the plants harboring them. Of those already men- tioned carbon bisulphid has many desirable qualities; but its poison- ous effect on vegetation is against it. It is possible that by applying it only during the dormant season of the plant and carefully regulat- ing the quantity applied it may prove as effective as it is claimed by some investigators to be against phylloxera in the vine. The writer’s experiments were mainly carried on at Miami, Fla., where there is no dormant season; hence this point could not be well determined. It is also conceivable that after a period of dry weather the chemical might be less harmful, as the trees would then be in a less actively 1 Gandara, 1906. 217 52 ROOT-KNOT AND ITS CONTROL. growing condition and perhaps, therefore, less injured when the root hairs were killed by the chemical. Further experiments on this line should be carried out. FERTILIZERS. It is the result of general observation that if trees affected by root- knot can be forced into rapid growth, especially in the early part of the season, so that the roots penetrate deeply into the ground and form a widely branching system, they will thenceforward usually develop normally and cease to show much injury from the nematode. This is particularly the case with the peach. Many growers now on setting out an orchard where the pest is present fertilize the trees very highly, so that they may start right into growth and keep ahead of the nematode injury. As shown on page 41, the nematodes are mostly confined to the upper 12 to 16 inches of soil, so that if the roots can be forced to grow rapidly and deeply enough they will escape much injury. To accomplish this, it is necessary that the soil be prepared to a good depth before setting out the trees and that an abundance of nitrogenous fertilizers be given. The various potas- sium salts, too, are apparently very beneficial in the Southeastern States, so much so that some people believe that they destroy the root-knot nematode. Perhaps in the naturally rather potash-poor soils of many of the Southern States the addition of potassium is simply another factor in bringing the plant to its normal resistant power. At any rate, in the writer’s experiments plants given an excess of potash suffered less from root-knot than those not so fer- tilized. It has been found in Germany that the sugar-beet nema- tode removes the mineral salts from the roots about equally. If, however, the soil is not much overstocked with potash it would be exhausted in the plant sooner than the others, for, being less abundant in the soil, it would be taken up less rapidly by the roots. The same would be true of any other of the necessary minerals. This may explain the effect of potash in combating this disease. FLOODING. In view of the fact that root-knot injury never seems to be severe in soils that are flooded for a part of each year it seemed reasonable to suppose that flooding might have a beneficial effect when applied to affected trees. Unfortunately, however, through a misunder- standing of instructions the experiments arranged to be carried out on this line failed to be performed. It is certain, however, that great care must be taken, for many trees are killed by having their roots submerged even a few days. 217 CONTROL OF ROOT-KNOT. 53 . CONTROL OF ROOT-KNOT IN THE FIELD WHEN NO CROP IS PRESENT. Land known to contain the root-knot nematode and not occupied by a permanent crop like an orchard, grove, etc., may be freed from the pest far more readily than land so occupied. The methods are the same, whether the land is to be planted subsequently to annual crops or to trees. The only difference is that land destined for perennial crops must be more thoroughly cleared of the root-knot nematode than that destined for simply one-year crops. CHEMICALS. Carbon bisulphid.—Carbon bisulphid is undoubtedly the most efficient chemical for the destruction of the nematode in fields. Experiments were made by the writer at Monetta, S. C., in 1906 and repeated in 1907, which showed that when used as previously described at the rate of 4 ounces per square yard of surface the nematodes were practically exterminated, being found only at the edges of the plats, where they could have come in from the surrounding untreated land. Two ounces per square yard did not prove so effective, although the nematodes were largely destroyed by even this application. In view, however, of the quantity required and of the high price of this chemical it is very evidently out of the question to apply it on a large scale. Even in bulk the crude carbon bisulphid costs 10 to 15 cents a pound. At 4 ounces a square yard the cost for an acre, not including cost of the labor required, would be from $120 to $180. Nearly all the chemicals that have been suggested have the same fault. Yet for small patches when it is desired, perhaps, to destroy the nematode where a tree is to be set out, or in a small spot where the pest has appeared but has not spread badly, it would probably be found very effective. Formaldehyde.—Formaldehyde was tested at Monetta, S. C., in both 1906 and 1907, and at Miami, Fla., as well, in 1906. Itwasapplied as a solution of 1 part commercia! formaldehyde (36 to 40 per cent) in 100 or 200 parts of water. The solution was either sprinkled directly on the surface or poured into deep furrows, which were leveled off after the solution had soaked in. From 1 to 2 gallons per square yard of surface were used. As a whole, the treatment did not recommend itself. In no case were the nematodes entirely destroyed, although they were considerably reduced in numbers. The plants grown on these plats after the treatment showed the presence of root-knot galls on their deeper roots, although most of the upper layer of soil seemed to be free from the pest. This would indicate that a larger quantity would perhaps penetrate deeply enough to kill all the nematodes in the soil. With formaldehyde at 20 cents a pound, wholesale, the cost of treating an acre with the stronger solution, 217 54 ROOT-KNOT AND ITS CONTROL. 2 gallons per square yard, would be about $150 exclusive of labor, which would include the hauling of 5,000 to 10,000 gallons of water. Calcium carbid.—At Monetta, S. C., experiments were made with calcium carbid. It was strewn in furrows which were then covered over so that the resulting acetylene gas should penetrate throughout the soil, or it was applied as a solution in water. The amount of root- knot was reduced, but in all cases where the reduction was great the injury to the crops, especially to tomatoes, was also great. Better results were obtained from the dry application in 2-inch furrows than from the solution. Planting was not undertaken for a week or two, but still the results were such that in spite of replanting a second and even a third time the test crops—okra, beans, tomatoes, and cowpeas— were badly killed out. The odor of acetylene was perceptible for sey- eral days. The fairly effective amounts were 1,500 pounds per acre, dry, in shallow furrows or a solution of 5 pounds per 100 gallons of water applied in deep furrows, 1 to 2 gallons per square yard. In view of the high cost of the treatment (at 10 cents a pound this would be $150 per acre exclusive of labor for the dry application and $25 to $50 for the solution) this method can not be recommended. The injury to vegetation is also against it. Potassium sulphocarbonate.—This salt is obtained commercially as a concentrated dark-brown solution, smelling strongly of sulphureted hydrogen. Gandara‘ states that it has been tried against phylloxera in France and recommends it for root-knot, at arate of 1 part of potassium sulphocarbonate to 5 parts of water. Accordingly, the following experiments were outlined. Plats of land were laid off as follows: (1) Check, no treatment; (2) 10 parts of the chemical to 90 parts of water, 2 quarts per square yard in holes which were quickly filled; (3) 1 part to 99 of water poured on the surface at a rate of 2 gallons per square yard, that being the quantity necessary to wet the surface thoroughly; (4) a similar quantity of a solution of 1 part to 199 of water; (5) check. After a few days beans, tomatoes, okra, and cowpeas (New Era) were planted. In all cases where the chemical was used, both weak and strong, the tomatoes, okra, and beans were to a large extent killed, but the cowpeas were not hurt. Root-knot was present, however, even where the solution was the strongest. As a fungicide, too, this chemical had little value, for Rhizoctonia was very abundant at the crowns of all the plants. For field use, then, this chemical is not to be recommended as a means of combating the root-knot nematode. Ammonium sulphate—Van Breda de Haan? recommended against the nematode on tobacco in the Dutch East Indies the use of am- monium sulphate followed by quicklime. The latter sets free the 1 GAndara, 1906. 2 Breda de Haan, 1905. 217 CONTROL OF ROOT-KNOT. 55 ammonia, which that author supposed might have value in destroy- ing the pest. The writer’s experiments at Monetta, S. C., were as follows: Plats of nematode-infested land 10 feet by 70 feet and 10 by 140 feet were laid off, separated from one another by ditches 2 feet wide. The chemicals were scattered on the surface and worked in with a cultivator or hoe. The rate per acre of the applications is here given, not the actual quantity put on the particular plats. (1) Water-slaked lime (quicklime put in a hole in the damp earth and left several days until slaked to a powder) 2 tons per acre, ammonium sulphate 1 ton per acre; (2) quicklime 2 tons, ammonium sulphate 1 ton; (3) slaked lime 2 tons; (4) quicklime 2 tons; (5) check. Sum- mer squashes were planted on one half of each plat and New Era cowpeas on the other half, both these crops being very susceptible to nematodes. Plats 3 and 4, respectively, slaked lime and quicklime, showed a very great abundance of root-knot, even more than plat 5, the check. The plants were pale in color and weak. Evidently lime in the quantities used is not effective against root-knot. In plats 1 and 2, ammonium sulphate plus slaked lime and quicklime, respectively, the squash roots were fairly badly knotted, especially in plat 1, but not nearly so badly as in plats 3 and 4 or in the check plat (5). The cow- peas were very dark green in color and very vigorous, and only moder- ately affected with root-knot, far less than plats 3 or 4, perhaps about like the check. The two plats with ammonium sulphate ripened their seed earlier than any other of the experimental plats. The next year these plats were again planted, this time to cowpeas, okra, tomatoes, and beans. The chemicals were not added, but observations were made to determine whether any beneficial effect might show the second year. The ammonium-sulpbate plats were distinctly better than the check or those with lime alone, and were only moderately affected with root-knot, although by no means free from it. Experiments similar to these but on a very much smaller scale were made in Miami, Fla. Quicklime, even at the rate of 5 tons to the acre, did not suffice to prevent nematode injury, while root-knot was quite abundant in a plat treated with quicklime at the rate of 2 tons per acre with 2 tons per acre of ammonium sulphate dissolved and poured over the surface. We must then conclude that these chemicals are not of special value for the combating of nematodes. Abbey! recommends using silicofluorid of ammonium at the rate of 1 ounce to asquare yard. It must not be applied to soil containing living plants, as it will kill them. It soon decomposes and then is 1 Abbey, 1898 and 1899. 217 56 ROOT-KNOT AND ITS CONTROL. harmless. Abbey also recommends 3 ounces of Little’s soluble phenyl in 3 gallons of water applied around affected roots. Dyke' and Iggulden? also tried the latter, but Dyke found it a failure, claiming, however, that kainit was effective. FERTILIZERS. Closely related to the use of chemicals may be considered the effect of various fertilizers on the development of root-knot. At Monetta, — S. C., the following fertilizers were tested in 1906, mostly in one- twentieth acre plats separated by ditches (or rather very deep furrows) 2 feet wide, the numbers in parentheses referring to the field numbers of the plats: (12) Kainit, 1,000 pounds per acre; (13) ammonium sul- phate, 667 pounds per acre; (14) kainit, 500 pounds per acre; (15) high-grade potassium sulphate, 1,000 pounds per acre; (16) check; (17) high-grade potassium sulphate, 500 pounds per acre; (18) 17 per cent acid phosphate, 1,000 pounds per acre; (19) 17 per cent acid phosphate, 1 ton per acre; (20) check. In 1907 the following tests were made: (1) Kainit, 1,000 pounds per acre; (2) kainit, 1,500 pounds per acre; (3) high-grade potassium sulphate, 667 pounds per acre; (4) high-grade potassium sulphate, 1,333 pounds per acre; (5) ammonium sulphate, 1,000 pounds per acre; (6) muriate of potash, 1,000 pounds per acre; (7) potassium magnesium carbonate, 667 pounds per acre; (8) potas- sium magnesium carbonate, 1,333 pounds per acre. The checks received no numbers in 1907. The plats of that year and the checks were planted to tomatoes, okra, beans, and New Era cowpeas, all of which are very susceptible to root-knot. The last year’s plats (1906 experiments) were also replanted in 1907 with these four plants. In 1906 the fertilizer plats were planted with New Era cowpeas and summer squashes. To all of the fields was applied each year, at the rate of 500 pounds per acre, a special brand of commercial fertilizer in common use in that vicinity, the soil being so poor that without some complete fertilizer nothing would grow well. The experiments were intended to show the effect, if any, of an excess of some par- ticular fertilizer over the normal quantity applied. The 1906 plats showed plainly the beneficial effects of potash fer- tilizers on the sandy soil of the experimental field. All the plats treated with kainit and potassium sulphate were darker green and the plants were far more vigorous than on the other plats. In fact, plats 12 and 15, respectively, kainit and potassium sulphate, both 1,000 pounds to the acre, were, so far as the cowpeas were concerned, hard to excel anywhere. The squashes did not show much difference in any of the plats. They were badly infested with the squash bug, 1 Dyke, 1897. 2 Iggulden, 1898. 217 CONTROL OF ROOT-KNOT. 57 which killed the plants out in some of the plats. The cowpeas in plat 12 showed no nematodes and but few were present in the squashes. Plat 14 had a fair amount of root-knot in the cowpeas and from few to many on the different squash plants. The rest of the plats did not differ materially from the check plats which were fairly badly affected, in spots very badly. The plants grown on these same plats in 1907 without the addi- tion of the fertilizers again were badly affected except in plat 12, and somewhat in plat 15, which remained fairly free, showing a residual effect. In the 1907 fertilizer experiments the following results were obtained. The kainit applications were injurious to the germina- tion of the seeds, both the 1,000 as well as the 1,500 pound applica- tion, but naturally the latter more markedly. The amount of root- knot, however, in these plats was slight. Potassium sulphate at 667 pounds per acre was not injurious, but at twice that amount it so injured the germination of the cowpeas and beans that they required replanting. Root-knot was fairly abundant and, strangely, more so in the more highly fertilized plat. In both plats the growth of the plants was very vigorous. The sulphate of ammonia at the rate used exerted a very harmful effect on germination, requiring several replantings. The plants that did grow, however, were very vigor- ous, dark green, and rather free from nematodes. The muriate of potash injured the germination of the beans and cowpeas, while the nematodes were fairly abundant. The potassium magnesium car- bonate gave the best and most vigorous plants of all, without injury to germination. Root-knot was present in most of the plants, but not abundant. Judging from these experiments, it is clear that fertilizers alone can not be depended upon to exterminate root-knot. On the other hand it is also plain that some fertilizers exert a beneficial effect upon the plant and enable it to make a good crop in spite of nematodes. Perhaps they may also increase the resisting power of the plant against the entrance of the nematodes into the roots. The potash fertilizers seem to be most favorable for this purpose, so far as the experiments at Monetta and observations elsewhere go. However, it will not be safe to conclude that they will be equally beneficial everywhere. In the sandy, rather potash-free soils of South Caro- lina and Florida the application of potash in amounts not too large seems to be followed by favorable results. According to Stift,! Hollrung, in Germany, has shown that ferti- lizing highly with potash alone is not of much benefit to beets attacked by the sugar-beet nematode. Wimmer has shown that the nema- 1 Stitt, 1908. 217 58 ROOT-KNOT AND ITS CONTROL. todes remove the different minerals almost equally, so that only where one element is rather deficient will the addition of that alone be of benefit. The sugar-beet nematode removes large quantities of mineral food from the roots, so that unless these minerals are present in the soil in considerable excess over that naturally needed by the crop the plants will suffer from lack of that mineral which is not sufficiently superabundant. Thus, an amount of potash sufficient for a healthy crop may be insuflicient if the sugar-beet nematode is present, and the symptoms of potash hunger can be averted only by applying an excess of potash. Probably this is also true of the root- knot nematode. The sandy soils of South Carolina are rather potash poor, so that a diseased plant will suffer from potash hunger, while the other elements may be in sufficient abundance. At any rate, the addition of potash in excess proved helpful. The nitrogen- containing fertilizers when not in too great excess also benefited the plants somewhat, but not so markedly as the potash. This is to be expected, as nitrogen is not any too abundant in those soils. The phosphatic fertilizers, however, showed no benefit at all. Caution must be taken not to apply too much potash. In 1907, in fact, kainit at 1,000 pounds per acre was harmful in that many of the young seedlings were killed, necessitating replanting several times in order to get a fair stand. This quantity was not harmful in 1906 on another plat, showing that the danger limit is probably not far below that amount. Muriate of potash at the same rate was very harmful in 1907, as was also the same amount of ammonium sulphate. Potassium sulphate, 667 pounds to the acre, and potassium magnesium carbonate, 667 and 1,333 pounds to the acre, were absolutely harm- less, while the latter amount of potassium sulphate was only slightly harmful. In spite of the high fertilization a field continually planted to nematode-susceptible crops will, if the nematode is present, eventually become so infested with that parasite that it will be impossible to make paying crops. However, it can not be denied that for special occasions it is of value to reduce part of the evil effects of the nematode infestation by high fertilization. FLOODING. The objections to flooding the soil that would apply in the case of land occupied by permanent crops do not hold good in fields devoted to annual or short-period crops. In the former case the soil can not be kept submerged longer than a few days or the roots are killed. In the latter case, however, the fields can be flooded for as long a period as desired before the crops are planted. There is no doubt that under such conditions flooding has value. This has already 217 CONTROL OF ROOT-KNOT. 59 been mentioned, reference being made to the conditions in the Ever- glade islands, where the never submerged tops of the islands are full of root-knot and the annually submerged sides are free from it. The writer has records of fields in Georgia badly infested with the root- knot nematode that were free from the trouble after a spring freshet that kept the ground submerged several days. Apparently flooding, unless possibly of long duration, will not kill the nematodes inclosed within the root galls, so that if such knotted roots of perennial plants are present the flooding must be continued much longer. In Yuma, Ariz., under the writer’s directions a field was flooded. It had once been a vineyard of Old World grapes, but these had become unprofitable owing to the ravages of the root-knot, and the vines had been cut down or pulled up. Many of the roots, however, were left inthe ground. The next year the field was planted to melons. When the writer saw the field in May, 1907, the young cucumber and melon plants were dying from root-knot and the pest was found in the old living grape roots. The field was flooded the following winter, but root-knot was again prevalent the following spring, although apparently not so abundant. It seems likely that the vine roots may have harbored and saved from destruction many nema- todes, or perhaps the flooding was not continued long enough. That under some circumstances even three weeks is insufficient appears to be the conclusion to be drawn from an experiment performed at the writer’s suggestion by a fruit grower and nurseryman in California. He kept submerged for three weeks his field of sandy alluvial soil which was badly infested by nematodes. Afterwards grape cuttings and peach seedlings were set out init. The grapes (a resistant sort, Rupestris St. George) showed no root-knot, but the peaches became knotted. This period seems excessive in view of laboratory results, and is not entirely free from doubt as to other possible means of in- fection, yet, until disproved, three weeks should be regarded as not enough time to exterminate the nematode by flooding. It is of interest that flooding the soil is claimed by Stift! to be of no value against the closely related sugar-beet nematode. Flooding, then, can not be recommended as a certain means of ex- terminating root-knot under all circumstances. Probably the soil should be flooded at least 25 days; in the laboratory the nematode larve usually succumbed much sooner when isolated and placed in water. Furthermore, no roots of perennial susceptible plants must be present. When water is expensive or means of flooding are not at hand, or when the soil is too porous, it will be out of the question to try this method. The subject is one, however, that needs further investigation. It will be of interest to call attention to the phenom- 1 Stift, 1903. 217 60 ROOT-KNOT AND ITS CONTROL. enon often observed that a sloping field may have nematodes at its upper or middle portion and be free from them at the lower end where the soil is water-soaked part of the year. DRYING. Laboratory experiments by the writer seem to show that the root- knot nematode can not withstand the drying out of the soil. Thus, two pots of badly infested earth, containing badly knotted plants, were allowed to remain without watering from June 4 to September 22,1908. The soil became very dry and dusty. It was then watered and seeds of susceptible plants were sown. These remained entirely free from root-knot. It is certain that the adults are killed by drying out, they being, indeed, very susceptible to injury of that kind. The foregoing experiments led the writer to the conclusion that thorough drying was fatal to larve and eggs as well. This was strengthened by the observation that in his cross-inoculation work where carefully washed root-knot roots of various plants were planted in sterilized pots of soil and seeds of the desired plants sown in the pots, infection was obtained wherever the roots used were fresh, while whenever they were somewhat wilted, not even dry, no infection was obtainable. Frank! and Stone? were also of the opinion that drying out was fatal to these nematodes. On the other hand, there are several recorded observations which would seem to indicate that the opposite is true, at least sometimes. Thus, Goldi* dried the roots of coffee affected with root-knot, both in the sun and in the shade. After two months he wet them up and soon found, with the aid of the microscope, numerous nematode larve, which he considered to be those of the root-knot nematode. A second case was as follows: Prof. P. H. Rolfs, of the Florida Agricultural Experiment Station,‘ kept some sandy soil in the laboratory for 10 months. It became dry long before the expiration of that period. The soil was watered and tomato seeds were sown. ‘The radicles of the seedlings became swollen and cedematous in a manner resembling the work of the root-knot nematode. No nematodes were found within the roots, but clinging to the outside were found nematodes which he identified as Heterodera radicicola. Géldi’s conclusions may have been erroneous, for there are many nematodes, almost indistinguishable from Heterodera radicicola in the larval state, that endure drying out for long periods. If they were examined only with the microscope and not tested in connection with living plants on which they could be grown to maturity, it would be almost impossible to tell whether those seen by Géldi were the one or the other. Prof. Rolfs, on the other hand, is not likely to have made 1 Frank, 1885. 2 Stone, 1899. 3 GOldi, 1892. 4 Rolfs, 1894, 217 CONTROL OF ROOT-KNOT. 61 a mistake of this nature, performing the experiment as he did. Still it is not certain that he had Heterodera radicicola unless he actually had the mature nematodes, but on this point he says nothing. There are some other nematodes besides this species that cause root galls, and it is barely possible that it may have been one of these, not the root-knot nematode that Prof. Rolfs had, since this latter species is rarely even partially external in the tomato. Yet with the confirma- tion of these reports by Dr. Cobb’s observations, it can hardly be doubted that under some circumstances some of the root-knot nematodes may survive drying out of the soil. Whether the drying out of the soil kills all the root-knot larve or not, there is no doubt that their activity ceases and there is no injury by them in fairly dry soils. In a letter to the writer, C. P. Lounsbury, entomologist of the Department of Agriculture of the Cape of Good Hope, states that the nematode occurs only in loose soils well sup- plied with moisture. Badly knotted grapevines set out in rather dry soil not only recovered, at least in part, but the nematodes did not spread to surrounding susceptible plants. Lavergne’ in Chile, Gandara? in Mexico, and Huergo * in Argentina also point out that dry soils are unfavorable to the development of root-knot. The writer has repeatedly sought for these nematodes in susceptible plants in dry soil outside of but in close proximity to badly infested irrigated fields in the semiarid parts of the country, but without success. In view of the foregoing facts, it is probable that deep plowing, so as to loosen up the soil quite deeply without harrowing to pulverize it, would permit it to dry out sufficiently in a dry season to reduce ereatly the injury from the pest. Of course, this is possible only where the climate is dry and the rainfall slight. In irrigated districts it could probably be carried on, such fields not being irrigated for some months after plowing. Of course this will not have much effect if underground seepage or rains keep the soil moist. Unfortunately the writer was unable to test the efficacy of this proposed method by direct experiment. It is a method that should be tested at the earliest opportunity in those regions where it can be carried out. TRAP CROPS. After Kiihn, the great German agriculturist, had demonstrated 4 that the so-called Ribenmiidigkeit (beet tiredness) of sugar-beet fields was due to a nematode, Heterodera schachti, he devised*® a method of reducing the injury based upon the principle of trapping the nematodes in some susceptible plant and destroying the latter before the larve which had entered the roots had reached maturity. For his trap crop he used a sort of summer rape. This was sown closely and 1 Lavergne, 1901. 2 Gandara, 1906. 3 Huergo, 1902, 1906. 4Kiihn and Liebscher, 1880. § Kiihn, 1881, 1882, 1886-1, 1886-2, 1891, 217 62 ROOT-KNOT AND ITS CONTROL. when the plants had grown long enough so that the first nematodes that entered the roots were not yet mature but were in the nonmotile stage they were plowed up and either removed and destroyed or turned under with the tops down and roots up. The plants treated in the latter manner died quickly and the nematodes in the exposed roots died within a few hours. By repeating this process several times (three to five) in a season the number of nematodes was found to be so reduced that good crops could be grown again for several years. In using this method extreme care must be taken to plow under or remove the plants at the right time, for if left too long the nematodes will reach maturity in the roots and lay eggs, thus increas- ing instead of diminishing the number of nematodes in the soil. Frank! and others have also recommended this method for com- bating the root-knot nematodes. The writer has found no record of any such experiment having been tried. He made experiments on this line two different years at Monetta, S. C., but with no success. A badly infested field was separated from adjacent plats by a shallow ditch, 2 feet wide. The plat was sown very thickly to Whippoorwill cowpeas, a variety susceptible to root-knot. Roots from numerous plants were examined microscopically at short intervals to determine the stage at which the nematodes first entering the roots had become motionless and were approaching sexual maturity. At that stage the plants were destroyed, on one plat by plowing them under, on another by loosening the roots and removing and destroying the plants, roots and all. The time necessary to reach that stage was found to be from 19 to 21 days after the sowing of the seed. As soon as the trap crop was removed or turned under, the soil was made ready and resown with cowpeas, the process being repeated. This was done until four or five crops of cowpeas had been removed in this manner. The next year through these plats and the check plat were planted rows of tomatoes, beans, okra, and New Era cowpeas. Some of these plants remained free, while some were slightly affected and some very badly affected by root-knot, no difference being noticeable be- tween the trap-crop plats and the check plats. This was true both in the experiments of 1906-7 and of 1907-8, which were conducted on another field. The cause of the failure of this method can not be that a sufficiently susceptible host plant was not chosen, for the variety of cowpea used is very susceptible. Furthermore, cowpeas had been grown fre- quently on that land, so that the nematodes were, so to say, accus- tomed to that crop. The period of growth allowed was carefully checked by microscopical examinations so as to avoid any chance of letting the development of the nematodes progress too far, for if that 1 Frank, 1885. 217 CONTROL OF ROOT-KNOT. 63 were permitted and egg laying were started the number of nematodes would be increased instead of diminished. Probably such large num- bers were present that only a part entered the trap plants and were destroyed, enough remaining in the soil to infest badly the next year’s crop. It is possible that some other crop would have done better, but it could not have been clover, as Frank suggested, for that did not do well where the experiments were being carried on. The requisites of a good trap plant are fairly cheap seed, great susceptibility to nematode attacks, a wide-spreading root system, and rapid growth. All these are possessed by the cowpea to a greater or less extent. STEAM. It has been seriously proposed to use steam to destroy nematodes in the field in view of the success with its use in the greenhouse, cold frame, and seed bed. The writer has made no experiments along this line, owing to the expense of the undertaking. It is seriously to be doubted whether a large field, producing a crop selling at $25 to $50 or even $100 net per acre, could be profitably piped for steam sterili- zation. Small fields isolated from danger of reinfection by deep ditches, water, stiff soil, or other obstacles and devoted to the inten- sive culture of some very remunerative crop might be so treated with profit. For a large field a very large boiler and many hundred feet of perforated pipe would be necessary.to steam the soil by the green- house method. Several schemes for sterilizing the soil in a field by means of moy- able apparatus have been devised, some of which have proved effective under certain conditions. Thus, for combating the Thielavia root-rot of tobacco, Gilbert 1! recommends the inverted-pan method of steam sterilization. This was devised by Mr. A. D. Shamel, of the Bureau of Plant Industry, for sterilizing nematode-infested soils in Florida. The following description is taken from Gilbert’s acceunt: The apparatus consists of a galvanized-iron pan, 6 by 10 feet and 6 inches deep, which is inverted over the soil to be sterilized and the steam admitted under pressure. The pan is supplied with steam hose connections, has sharp edges, which are forced into the soil on all sides to prevent the escape of steam, and is fitted with handles for moving it from place to place, the weight of the entire pan being not over 400 pounds. The soil is prepared as in the greenhouse method, a few potatoes being buried at a depth of a foot to gauge the degree of heat attained. A soil thermometer may also be used if desired. The steam should be kept at as high a degree of pressure as possible, 80 to 100 pounds being best, and the treatment should continue for one to two hours, depending on the pressure maintained. In experiments conducted in the spring of 1907, one hour’s steaming at 80° C. under 100 pounds pressure gave best results in killing both the fungus and the weed seeds. When one section of the bed is treated, the pan is lifted and carried to an unsterilized portion and the operation repeated until the entire bed is steamed. 1 Gilbert, 1909, pp. 35-36. 91294°—Bul. 217—11——5 64 ROOT-KNOT AND ITS CONTROL. The great objection to this method, and one that makes it imprac- ticable except for use on small spots, is the smallness of the area that can be treated at one time. Even with a pan of twice the area of that described, and allowing only one hour’s sterilization each time, it would require more than 15 days, working day and night, to sterilize the soil on one acre of land. Furthermore, for deep soils, where, as already explained, the nematode sometimes is present at a depth of more than a yard, it is extremely doubtful whether the steam would penetrate deeply enough to destroy all the nematodes. This last objection applies to all methods of sterilization where an attempt is made to kill the nematode by heat or poisons. FALLOW. It is self-evident that if a field be kept free from all vegetation for a long enough period all the plant-parasitic nematodes within the soil will die from starvation. This is the principle involved in the use of the bare fallow. The field is plowed and kept free from weeds and other plants by frequent cultivation. In those localities where the winter is cold enough to prevent the further development of the nematodes during that period, it does no harm if grass or weeds grow up after the weather has become decidedly cool. This date might safely be put at November 1 for North Carolina, South Carolina, northern Georgia, Alabama, Mississippi, northern Louisiana, and northern Texas. In central and southern Florida and probably the southern portion of Texas and Louisiana, however, the nematode is active the year around, so that it would be necessary to keep the ground bare the whole time until the nematodes had died. In the early spring, where vegetation was allowed to grow in the winter, the cultivating to keep down the weeds must be taken up again before the soil begins to warm up. The length of time necessary to remain in fallow is not certainly known. Mr. A. D. Jackson, of Denison, Tex., found that 15 months in fallow was not sufficient to rid a field of root-knot nematodes entirely, although the number was greatly diminished. On the other hand, two whole years seem to be amply sufficient. This method has some objections which make it impossible to use in some localities. The land is idle and not only not productive, but requires the expenditure of time and labor to keep the vegetation down. Furthermore, the light soils where the nematodes abound are easily leached out when there is not a covering of vegetation. Then, such soils are subject to bad washing during heavy rains when they have no plant roots to bind them in place. A further objection is the destruction of humus in the soil exposed directly to the action of the fierce summer sun. The use of this method therefore can not be universal, although it is successful where it can be put into effect. 217 CONTROL OF ROOT-KNOT. 65 NONSUSCEPTIBLE CROPS. The most promising method, and the one that has given the best results wherever carefully tried, is that of growing crops that are not subject to root-knot until the nematodes causing the disease are starved out. To carry out this method successfully several things are requi- site: (1) The crops planted must be free from nematode attack, so that the larvee in the soil may not be able to find any nourishment to sustain their life and enable them to undergo their development. (2) The crop grown should at least pay the expense of working the land, as well as the rent, taxes, etc. (3) At the same time, if possible, the crops should enrich the land, or at least not impoverish it. (4) The plants must make such a vigorous, dense growth as to choke out all weeds or other plants that might harbor nematodes and permit them to develop and produce their numerous eggs. On referring to the list of susceptible plants it will be seen that with few exceptions none of the ordinary farm crops fulfill the first require- ment. However, the following plants appear to be free from nematode attack, at least under most conditions: Cowpea (the Iron variety), all species tested of Stizolobium (the velvet bean and close relatives), Florida beggarweed (Meibomia mollis), peanut (Arachis hypogaea), rye (Secale cereale), most varieties of winter oats (Avena sativa), crab- grass (Syntherisma sanguinalis), and possibly a few others. Webber and Orton * first called attention to the nematode-resistant quality of the Iron cowpea and recommended its use in combating root-knot. The velvet bean and beggarweed have been recommended by Rolfs,? of the Florida Agricultural Experiment Station, who has also pointed out the value of crab-grass in a plan of rotation for reducing the num- ber of nematodes. Thus, he found the nematodes far less abundant the next year after an infested field was allowed to grow up to crab- grass for one year. The following rotations were planned by the writer for his work at Monetta, S. C., there being four plats measuring, respectively, 0.152, 0.217, 0.217, and 0.166 acre: TaBLe III.—Rotation of crops planned for four experimental plats at Monetta, S. C. Season. Plat 1. Plat 2. Plat 3. Plat 4. he rae Winter.........| Abruzzesrye...... Abruzzes rye....-- Virginia winter oats...| Virginia winter oats. Summer....... Beggarweed....... Velvet bean....... Velvet bean.......-... | Beggarweed. This experiment was planned for three years. It was begun in the fallof 1905. It was planned to keep careful records of all yields, etc., but in some cases the records are lacking. Unfortunately, the soil 1 Webber and Orton, 1902. 2 Rolfs, 1898. 217 66 ROOT-KNOT AND ITS CONTROL. proved so very poor for the oats that forit was substituted Abruzzes rye in succeeding years. Once each yearthe land was fertilized with the special commercial fertilizer previously mentioned at the rate of 500 pounds per acre. The grain was harvested when mature, thrashed, and measured. As soon as the land could be put into proper condition the beggarweed and velvet bean seed were sown. In October a measured part of each field was carefully mowed and the vines cured to hay and weighed, thus permitting an approximate estimate of the actual yield per acre. The grain was sown as soon as the hay crop was cut and the land prepared. Unfortunately it was impossible, in addition to the substitution of rye for oats, to carry out the rotation just as planned, for in 1907 the beg- garweed seed obtained germinated so poorly that those plats were resown to velvet beans, as it was then impossible to get good beggar- weed seed. In the summer of 1908 across the south edge of the field rows of tomatoes, beans, okra, and New Era cowpeas were planted to test the degree to which the nematode infestation had been reduced by two years of these rotations. In the spring of 1909 another strip was sown to the same four kinds of plants, the remainder being planted with two varieties of cotton, viz, Triumph and Columbia. A similar area to the north of the rotation fields was also sown to the same sorts of cotton, while to the east was a field of Peterkin cotton belonging to a renter and not planted with reference to the experiment. The choice of the field to the north was made through an unfortunate misunder- standing. It was not discovered until the planting was done and the plants above the ground that that field too had undergone somewhat of a rotation, viz, 1906, cotton; summer of 1907, Iron cowpea; winter of 1907-8, rye; summer of 1908, Iron cowpea; winter of 1908-9, rye. The field to the east, which was sown to Peterkin cotton, was in cotton for the third successive season. The experiments were further interfered with by torrential rains which were harmful in two particulars, viz, they washed out much of the cotton and brought soil from nematode-infested fields and depos- ited it on parts of the rotation piats. 217 CONTROL OF ROOT-KNOT. 67 The yields on the plats were as follows: TasLE 1V.— Yield of crops on four experimental plats at Monetta, S. C. Season and year. Crop. Actual yield. saaen cop potest. OP SOE ae Beene ee cea ee ee eee ee IS tilde cor'siae aseecice |Seee cee Spring of 1906... . Rye Me RAD. REL. Ce AC be ag 2 5,42 : Welven beamthaye. 6p. os ce ceacneh ee ae nue pounds..| About 4,900 11, 300 Fall of 1906. ........ pence, (GG Haye earee a by RR eee ee ay oh He Free do....| About 1,575 5, 000 Spring of 1907...... 1595 Ie eae OE oA EE OLS 2 ee eee SO EES bushels. - 10} 14 Fall of 1907 Ky he et bean hay on own plat..............-..- pounds..| About 1, 600 BA pata Baa? Velvet bean hay sown !ate on beggarweed plat ...do....| About730 | 2,300 Spring of 1908...... Ey ee Ae eae Ec reeree senha os bushels 1. . 104 14 elvet bean hay---.------- Re es etary tabs iain ae pounds.-| About 3,840 8, 850 vie of 1908. ..-..... {Begearw reed hay See. ee EP RR ae eh eee Ree 550.022 About 560 | 1,770 Spring of 1909...... FV Gyan precicr. a Mere tes Sere ania Ae ae ee Samak ee cll pa EN cn ea ea 1204 bushels on 14 acres; therefore Enid at 104 bushels for that field, 0.752 acre. 2 Cut before ripening to allow cotton to be planted. At the prices current at Monetta, S. C., for hay (about $18 per ton) and grain ($3 per bushel in 1909 for seed, but here estimated at $1 per bushel) the value of the hay produced in the three years amounted to about $117 and‘that of the grain to $22.50, a total of $139.50, at the rate per acre of $156, $30, and $186, respectively, an average of $62 per acre per year. While these yields are probably considerably more than enough to pay for working the land and the rent of the land besides, as well as payment for the seed, velvet beans having cost about $4 per bushel, it must not be concluded that the experiment was a failure in that the yields were not greater, for the primary purpose of the rotation was to reduce the nematode infestation while improving the land, or at least keeping it from deteriorating, and yet to make enough money to pay for the labor and seed used. To test to what extent, if any, the land was improved was the pur- pose of planting a plat of cotton at the north of the rotation plat. Unfortunately, so many plants in each section were washed out by the heavy rains that a very poor stand was obtained, with the result that the yield per acre on the rotation and check plats could not be deter- mined. The yields of the unginned cotton on the rotation plat were at the rate of 1 pound of cotton for 6 plants of Triumph and 6.1 plants of Columbia, while on the control plat to the north it took 6.9 and 7.25 plants, respectively, to make a pound. The Peterkin plants to the east were not half as large and yielded even less. The soil which at the beginning was very poor in humus, so poor in fact that the rye would scarcely grow and the oats did not pay for cutting, gave a much better appearing field of rye the following years. The foliage of the cotton on it had a good color, showing that the leguminous crops had increased the nitrogenous content of the soil. 217 68 ROOT-KNOT AND ITS CONTROL. From the standpoint of nematode extermination the results were very satisfactory. Both in 1908, after two years of this rotation, and in 1909, after three years, the susceptible plants on part of the plat remained free from root-knot except as specified below. These plants were, as in previous tests, tomatoes, okra, beans, and New Era cowpeas, all extremely susceptible to root-knot attacks. Sev- eral rows of each were planted in 1908 along the southern edge of the plat, and in 1909 on the part just adjacent to that on the southern part of that portion of the field which had had a rotation of three years. Every plant was carefully dug up and all its roots examined after freeing them from the adhering soil. Every such plant was recorded as free, slightly affected, or seriously affected, a separate record being kept of all the plants in each hill. The field slopes very gradually toward the south from higher, somewhat nematode-infested land on the north. Two slight de- pressions lead somewhat diagonally from the northwest to the south- east. In the spring of 1908 and again in the early summer of 1909 Monetta was visited by torrential rains which flooded and very badly washed the fields. Considerable soil from the fields to the north, and especially the badly infested field to the west, was washed down these depressions, settling on them and in the lower (southern) edge of the rotation field. Where these deposits of dirt occurred, and con- fined to these areas, some of the plants showed more or less nematode injury, most near the middle and least along the edges of the depres- sions. Furthermore, a few plants at the edges of the field, 1. e., at the east and west ends of the rows, showed nematodes where they were probably introduced from the adjoining land in cultivating, plowing, etc. All the rest of the plants remained nematode free, although this field was badly infested before the experiment began. In accordance with suggestions of the writer, Mr. A. D. Jackson, of Denison, Tex., made some rather similar experiments, using Iron cowpeas and rye as his rotation. Certain fields were very badly infested, so badly, indeed, that the crops on them were almost a total failure. By growing the cowpeas two seasons with rye as the winter crop the nematodes were so reduced in number that only 20 hills of cantaloupes out of half an acre were affected with root- knot and the crop of melons was excellent. Under date of July 10, 1909, Mr. Jackson wrote as follows: Iam well pleased with the Iron pea. While I have not eradicated the pest entirely by growing the pea two seasons, I have enriched my soil, have grown a large crop of feed, and the succeeding crop of vegetables has not in any case been materially af- fected (by nematodes). In Mr. Jackson’s fields the writer’s and Mr. Jackson’s conclusions were that the few nematodes surviving were those that were pro- 217 FREEING A FIELD FROM ROOT-KNOT. 69 duced on the few weeds whose presence it was impossible absolutely to prevent in the cowpeas. Thus, the weed known as careless weed (Amaranthus sp.) was found to have root-knot in the field of Iron cowpeas the second season these were grown. Mr. Jackson also made the experiment of using summer fallow in combination with winter rye, as follows: The preceding crop was taken off the summer of 1906, being badly knotted. The field was then kept in bare fallow from August, 1906, until the fall of 1907, when it was sown torye. This was turned under when about mature, and in July, 1908, the field was sown to tomatoes (which are especially susceptible to root-knot). A fine crop of tomatoes resulted, the only nematodes present being in a small part of the field where Irish potatoes were badly attacked in 1906 and where volunteer potatoes came up in 1907. The remainder of the field remained free the succeeding year also (1909). Prof. P. H. Rolfs + recommends letting the field grow up to crab- grass (Syntherisma sanguinalis) after the crops are removed, first taking up and burning or otherwise destroying the plants to avoid infection from them. According to him this method when used even for only one year greatly reduces the number of nematodes present. Dr. Neal? recommended the use of beggarweed, Japan clover, or Mexican clover. Regarding the latter the present writer knows nothing, but the first two are practically, if not entirely, immune and so ought to be valuable for this purpose. This method was used with compiete success by Schroeder? in Germany against the stem nematode (Tylenchus dipsaci) after all other practicable methods had failed. He planted infected fields for a series of years with crops not susceptible to the nematode. After this period the fields gave again their normal yields of susceptible plants. RECOMMENDATIONS FOR FREEING A FIELD FROM ROOT-KNOT. In view of the results of the experiments described, the writer would make the following recommendations for freeing a field from root-knot. If the situation is one where the winters are cold and cool weather sets in in October, it will not be necessary to give attention to the subject during the fall and winter or in the spring before the ground begins to warm up. Under such conditions it would probably suffice to plow the land in the autumn, so as to have it in good condition for as early planting as possible in the spring. In the spring the field should be kept free from vegetation by cultiva- tion or harrowing until the ground is warm enough to plant cowpeas. The field should then be planted thickly with Iron cowpeas, this 1 Rolfs, 1898. 2 Neal, 1889. ® Schroeder, 1902. 27 70 ROOT-KNOT AND ITS CONTROL. variety being usually sufficiently resistant to the root-knot to permit its use for this purpose. In the fall this can be cut for seed or hay. The ground should then be plowed up and the process repeated the next season. Except in exceedingly bad infestations, two seasons devoted to Iron cowpeas should be sufficient to free the land from the pest. If desired, some winter grain, preferably rye or perhaps wheat, may be sown in the fall, the cowpeas not being planted until the crop is harvested early the next summer, following them by grain again. Where the weather remains warm rather late in the fall it would be desirable always to do this and so prevent the growth of weeds which might harbor the nematode in the fall and winter. Where the summer is long enough, velvet beans or Florida beggarweed are perhaps preferable to cowpeas, as they give a denser growth that more completely smothers out all weeds. Special care must be taken that in the summer time no weeds are allowed to grow in the field, as it will be seen by reference to the list of susceptible plants that many of the common weeds harbor the nematode. Their presence in the field, therefore, would serve to perpetuate rather than kill the nematode. Where practicable, the surest results can be attained by keeping the ground absolutely bare of all vegetation for two years. This can not be done on some soils, owing to the danger of the destruction of humus by the hot sun or of washing by heavy rain. Where the field is free from roots of perennial plants which might shelter the pest and is so situated that it can be submerged easily for long periods, it may pay to flood the land for three or four weeks, or perhaps during the winter. This would be impracticable except in a few locations. Furthermore, in many soils it would leach out all the plant food and make the soil poor, but where an impermeable layer will hold the water and keep it from leaching out it is conceivable that this method might be found very satisfactory. A short period of flooding or attempting to do this while the soil contains perennial roots containing the nematode will hardly prove successful. In the irrigated districts of the West, special care should be taken to avoid the introduction of this nematode into lands devoted to potato raising. To this end only perfectly sound, clean potatoes should be used; no potatoes from suspected regions should be planted, even should the individual potatoes appear perfectly healthy, with- out a preliminary sterilization with formaldehyde solution to destroy any nematodes present in the adhering soil. Should none of the foregoing methods be feasible, high fertiliza- tion, especially with that element (potassium calcium or phos- phorus) which is most nearly deficient in the soil, will prove helpful, although it will not kill the nematodes. When, as is often the case in 217 BREEDING STRAINS RESISTANT TO ROOT-KNOT. 71 the sandy soils of the southern United States, the soils are already deficient in potash, rather strong applications of some of the potash fertilizers—for example, kainit, potassium magnesium carbonate, sulphate of potash, etc.—are very helpful. Care should be taken not to apply enough to prevent the germination of the seed. BREEDING STRAINS RESISTANT TO ROOT-KNOT. As already mentioned, Webber and Orton have shown! that the Iron variety of cowpea is practically immune to root-knot and wilt (Neocosmospora vasinfecta), while most other sorts are exceedingly susceptible to both diseases. The latter investigator has continued his breeding experiments, using the Iron cowpea as one of the parents, and has produced several varieties more prolific than that sort in which the resistant characteristics are present. Similarly in the breeding of tobacco, Shamel and Cobey? obtained a strain resistant to nematodes. Certain sorts of figs—for example, Celeste and Pou- lette—are said to be less subject to injury by nematodes than other kinds. Among grapes, so far as the writer’s observations go, the Old World species (Vitis vinifera) seems to be especially liable to injury by root-knot, although the different sorts vary greatly in their susceptibility. Thus, Zinfandel and Muscat appear very subject to this trouble, while Sultanina (erroneously called Thompson Seedless) is apparently not so easily injured. Some of the phylloxera-resistant hybrids and pure American sorts are practically immune to root- knot as well as to phylloxera, although some American sorts are quite badly affected by the nematode. These observations of the writer are confirmed by Lavergne, who states * that the European varieties are very susceptible to Anguzllula vialae, as he calls the root-knot nematode, while those of American origin that are resistant to phylloxera are also resistant to root-knot. Of the watermelon- citron hybrids bred by Mr. Orton with resistance to wilt as the main aim, it was found by the writer that of one strain only 4 out of 333 plants showed root-knot, i. e., 1.2 per cent, while in two other strains 28 and 51.9 per cent, respectively, showed root-knot. The presence of such marked differences shows that it would be entirely feasible to breed a watermelon variety that would be practically immune to root-knot as well as to wilt. Bouquet de la Grye*‘ points out that Coffea liberica is less susceptible to root-knot than C. arabica and recommends grafting the latter upon the former. To obtain a firm union, this must be done by an approach graft with seedlings. Simple selection can be and ought to be practiced by everyone who erows his own seed; more complicated breeding work, unless per- 1 Webber and Orton, 1902. 2Shamel and Cobey, 1907. % Lavergne, 1901. ‘4 Bouquet de la Grye, 1899. 217 o 72 ROOT-KNOT AND ITS CONTROL. formed by men who can devote considerable time to it, hardly pays for the time and expense required. In carrying out simple selection we must remember that no new characters are originated by this method. We simply select and strive to fix in one strain certain characters that are present as variations in the plants we are working with. Thus, if we find in a field badly infested with nematodes that a certain proportion of the plants are free from root-knot while the rest succumb, it would probably pay to begin selecting seed from the unaffected plants. It is better still if we can inbreed or intercross similar resistant plants. On the other hand, resistance to nematodes seems sometimes not to be one of the variations occurring in a plant. Such a plant can not be selected, as there is no foundation on which to build. However, by crossing it with some nearly related nonsusceptible sorts, some of the progeny may possibly show desirable qualities of resistance while at the same time preserving the best qualities of the parent sorts. In all such breeding it must be borne in mind as a very important principle that this work should be done in badly infested fields. If naturally infested fields are not available, provision should be made to do this work where the disease is abundant. No attempt will be made here to describe the methods of selection or hybridization. These are known to all seed growers and breeders. They can be found described in detail in many publications." Every farmer ought to be able at least to carry on this simple selection: When any plants in an infested field show special vigor and freedom from root-knot they should be marked and the seed collected before the main crop is gathered. This should only be done, how- ever, if these resistant plants are also up to standard in all other features. SUMMARY. (1) The disease known as root-knot, characterized by enlargements of the roots and often leading to the death of the plant affected, is caused by a nematode (Heterodera radicicola (Greef) Mull.). This was probably originally native in the Tropics (of the Old World ?), but has spread into nearly every part of both Temperate Zones. (2) The plants recorded as more or less subject to attack number almost 480 species and varieties, including nearly all of the larger families of flowering plants. Probably many more are actually susceptible, but have not been reported yet as hosts. Most of the important field and garden crops and ornamental plants are more or less subject to root-knot. 1 Hays, 1901; Bailey, 1906; Orton, 1909; Reed, 1909; Salmon, 1907; Spillman, 1909; Wilcox, 1903; Oliver, 1910. 217 SUMMARY. 73 (3) The life cycle of this nematode, from egg to egg, may take place in four weeks, or longer, depending upon the temperature of the soil. The larval stage is that in which entry into the host takes place. It then becomes motionless and soon enlarges and undergoes a sort of metamorphosis, the males eventually recovering the original worm shape, while the females become pear or flask shaped and very much enlarged in their transverse dimensions. Each female lays 500 or more eggs. The winter is passed probably most frequently in the larval stage in the soil, but in the case of galls on perennial roots the nematodes may overwinter in these in a more advanced stage, even as practically mature and perhaps already fertilized females. (4) For the rapid multiplication of the root-knot nematode the following conditions are necessary: (a) A certain degree of warmth of the soil. Thus, in southern Florida this nematode is active the year round, in part of South Carolina the active season is from April 20 or May 1 to the middle or end of October, while farther north the period is still shorter. (6) Loose-textured soil. Only sandy or at least light soil is favorable to its spread. (¢) Moisture. The drying out of the soil is frequently fatal to the nematode and in any case prevents it from doing any harm. Apparently the moister the soil as long as it is well supplied with air, the more favorable it is to the nematode’s development. However, wet soil, 1. e., soil in which the air spaces are filled with water, is at length fatal to the nematode. (d) Food supply. The larve are able to exist in the soil for more than one year, but apparently not for two years, without the presence of living plants into which to enter. They are apparently unable to develop beyond the larval stage unless they enter a suitable host plant. (5) The nematode is distributed in several ways: (@) The larve move through the soil by their own motion, but the distance traversed thus is probably not more than 6 feet or so a season. (b) They are carried from field to field in the earth clinging to imple- ments, the hoofs of animals, the shoes of laborers, wagon wheels, etc. (c) They are conveyed in the soil that is washed from one field to another by heavy rains, a very common mode of distribution of this pest. (d) Itis possible that heavy winds may carry larve or eggs with the soil blown from one field to another, but probably most would be so dried out in the process that this is not much to be feared. (e) They are introduced into new places in the roots or in the dirt adhering to the roots of nursery stock, in rooted cuttings, potted plants, ete., especially those of the peach, grape, fig, mulberry, potato, ginseng, etc.; also in the dirt in which some seeds are packed. (f) They are 217 74 ROOT-KNOT AND ITS CONTROL. sometimes brought to a field in manure if the manure pile has stood on infested soil. (6) The following methods of control in greenhouses and seed beds may be used: (a) The most efficient method is the use of live steam at fairly high pressure. The steam is forced through a system of per- forated pipes laid at the bottom of the bed or bench. (b) The old infested soil may be entirely removed and the benches thoroughly cleaned out. Then noninfected soil may be put in its place. This method is not advisable in regions where the nematode occurs out of doors in the vicinity. (c) Infected soil, when it is desired to save it and steaming is impracticable, may be freed by allowing it to le through the winter in a place where it will be exposed to alternate freezing and thawing, and especially to drying. (d) Soil containing perennial plants can be nearly if not quite freed from nematodes by the use of an abundance of a solution of formaldehyde (1 part of com- mercial formaldehyde to 100 parts of water). This solution is fatal to many plants and can be used only with great caution. (7) For the control of the nematode in the field where the land is occupied by perennial crops no entirely satisfactory chemical applica- tion can be recommended. Places where trees are to be reset should be freed from nematodes by the use of carbon bisulphid at a rate of 3 or 4 ounces per square yard placed in about nine holes per square yard, these holes being about 6 to 12 inches deep and to be filled with dirt as soon as the chemical is placed in them. Carbon bisulphid can not be used with safety around living trees. Flooding the land seems to be unsatisfactory, as flooding long enough to kill the nematodes is usually fatal to the trees. High fertilization and constant culti- vation to induce growth often so help the trees that they are able, as it seems, to outgrow the trouble, the roots either penetrating: to levels where the nematodes are less abundant or being formed faster than the galls can be produced. Avoid growing susceptible cover crops, like the ordinary nonresistant varieties of cowpeas, for exam- ple, for these multiply the nematodes in the soil manyfold. In pre- paring the land for setting out a perennial crop the soil should be freed from nematodes by the use of the methods suggested below. (8) For land infested with nematodes and not bearing a perennial crop, the following methods may be recommended: (a) Keeping the land free from vegetation of all kinds for two years. This is the most effective method, but it is not practicable in many cases. (b) Planting the land to nonsusceptible crops for at least two (perhaps better three) years, using in the winter small grains, such as wheat, rye, or oats, and in the summer the velvet bean, Florida beggarweed, the Iron cowpea, or even peanuts, scrupulously destroying all weeds that might harbor the nematodes. (¢) Making heavy applications of 217 SUMMARY. 15 fertilizers, especially those containing potash, except where the soil already contains this in abundance. This treatment often reduces nematode injury greatly. (d) Flooding the land for a period of some weeks. (e) Where rain is not likely to interfere, plowing and allowing the soil to dry out for several months. (f) Preventing, by the use of embankments, ditches, ete., the washing of soil from infested fields to the field which it is desired to free from the pest. The intro- duction of the pest by tools, wagons, farm animals, etc., should be avoided. The trap-crop methods and the use of various chemicals have not proved practicable as tested by the writer. The former needs, perhaps, further trial. (9) The ideal procedure is to develop nonsusceptible strains of plants, so that the expense and trouble of exterminating the pest may be avoided. Such strains may be obtained by the selection of more resistant plants or by crossing with resistant strains followed by the careful selection and breeding of the progeny. Nore.—While this bulletin was in press, there appeared a note in Science,t by L. N. Hawkins, describing the occurrence of Heterodera radicicola in the roots of Typha latifolia near Ithaca, N. Y. The writer has just received from Mr. G. L. Fawcett, plant patholo- gist of the Porto Rico Experiment Station, Mayaguez, P. R., speci- mens of the bark near the base of a 15-year-old coffee tree. Mr. Fawcett writes: ‘‘The disease is characterized by a roughening of the bark at the base of the coffee tree, extending from the surface of the soil upward for a foot or two. No doubt it injures the tree, but such injury must be slight. I have seen no sick tree the bad condi- tion of which could clearly be ascribed to this nematode; only a small percentage of the trees in any plantation are infested. It is perhaps more common in moister and more shady places. Older trees, say, those of 15 years or more, are the only ones noticed with this disease.” The living portion of the cortex was found to be very densely infested with mature females of Heterodera radicicola. It seems probable that these nematodes must have passed upward through the soft tissue of the cortex from some original infection in the root. It is worthy of note that sometimes in herbaceous plants, such as tomato, the writer has found nematodes 6 inches or more above the level of the ground within the cortical tissue of the stem. 1 Science, n. s., vol. 34, no. 865, July 28, 1911, p. 127: 217 BIBLIOGRAPHY. Papers seen by the author are indicated by an asterisk (*). All not so marked have been accepted on the authority of other writers. Only those titles to which reference has been made in the text are included in this list. This is not, therefore, a complete bibliography of all papers pertaining to this nematode. Axsspey, G. Eelworm destruction. Journal of Horticulture, London, ser. 3, vol. 36, January 6, 1898, p. 16. Eelworm in vine roots. Journal of Horticulture, London, ser. 3, vol. 38, Janu- ary 5, 1899, pp. 14-15, figs. 3-4. * ATKINSON, GEorGE F. A preliminary report upon the life history and metamor- phoses of a root-gall nematode, Heterodera radicicola (Greeff{') Miill., and the injuries caused by it upon the roots of various plants. Science Contributions from the Agricultural Experiment Station, Alabama Polytechnic Institute, Auburn, Ala., vol. 1, no. 1, December, 1889; Bulletin of Agricultural Experiment Station, n. s., no. 9, 1889, 54 pp., 6 pls. Diseases of cotton, Bulletin 33, Office of Experiment Stations, U. 8. Dept. of Agriculture, 1896, pp. 279-316. *Bartey, L. H. Some troubles of winter tomatoes. Bulletin 43, Cornell Agricul- tural Experiment Station, 1892. a Plant-breeding; being six lectures upon the amelioration of domestic plants, 4th ed., New York, 1906, 483 pp., illustrated. Baxer, H. Employment for the microscope, London, 1753, chap. 4, p. 250. BarBer, ©. A. A tea-eelworm disease in South India. Department of Land Rec- ords and Agriculture, Madras, Agricultural Branch, vol. 2, Bulletin 45, 1901, pp. 227-234, 3 pls. *BerKeELeEY, M. J. Vibrio forming cysts on the roots of cucumbers. Gardeners’ Chronicle, London, 1855, p. 220, 2 figs. *BovuquETDELAGRYE. La régénération des plantations de caféiers dans les Antilles, Bulletin des Séances de la Société Nationale d’Agriculture de France, Paris, vol. 59, 1899, pp. 683-687. * BREDA DE HAAN, J. VAN. Levensgeschiedenis en bestrijding van het tabaks-aaltje (Heterodera radicicola) in Deli. Mededeelingen uit ’s Lands Plantentuin, Bata- via, 1899, no. 35, pp. 1-69, 3 pls. Wortel-ziekte bij de peper op Java. Verslag omtrent den Staat van ’s Lands Plantentuin te Buitenzorg over het Jaar 1904, Batavia, 1905, pp. 21-39. *Bricx, ©. Bericht iiber die Tatigkeit der Abteilung fiir Pflanzenschutz fir die Zeit vom 1 Juli, 1904, bis 30 Juni, 1905. Jahrbuch der Hamburgischen Wissen- schaftlichen Anstalten, vol. 22, 1904, p. 299-311. 1905. Casaut, ©. L’Heterodera radicicola Greef nelle radici del nocciuolo. Giornale di Viticoltura e di Enologia, vol. 5, 1898, p. 4. Currtot, J. La maladie noire des clématites 4 grandes fleurs causée par |’ ‘‘ Hete- rodera radicicola Greeff.”?! Semaine Horticole, 1900, pp. 535-537. Bulletin de la Société des Sciences Naturelles de Saone-et-Loire, n. s., vol. 6, 1900, pp. 128-134. * * 1 The name of Greef is misspelled, as shown in the title of the paper cited. 217 76 BIBLIOGRAPHY. ie *Coss, N. A. Tylenchus and root-gall. The Agricultural Gazette of New South Wales, Sydney, 1890, vol. 1, pp. 155-184, figs. 1-8, pl. 4. * Root-gall. The Agricultural Gazette of New South Wales, September, 1901, vol. 12, no. 9, pp. 1041-1052, figs. 1-8. The internal structure of the gall-worm. The Agricultural Gazette of New South Wales, Sydney, October, 1902, vol. 13, no. 10, pp. 1031-1033, fig. 1. *Cornu, Maxime. Sur une maladie nouvelle qui fait périr les Rubiacées des serres chaudes(Anguillules). Comptes Rendus Hebdomadaires des Séances de l’ Académie des Sciences, Paris, vol. 88, 1879, pp. 668-670. (1879-1.) Etudes surle Phylloxera vastatrix. Mémoires Présentés par Divers Savants & l’Académie des Sciences de l|’Institut de France et Imprimés par son Ordre, Paris, ser. 2, vol. 26, 1879, pp. 1-357, pls. 1-24. (1879-2.) * CRAMER, P. J.S. Nematoden in ropusta-koffie. Teysmannia, vol. 17, no. 3, 1906, pp. 191-192. Datta Torre, K.W.von. Die Zoocecidien und Cecidozoen Tirols und Vorarlbergs. Berichte des Naturwissenschaftlich-Medizinischen Vereines in Innsbruck, vol. 20, 1892, pp. 90-172. * Darpoux, G.,and Hovarp,C. Catalogue systématique des Zoocécidies de l’ Europe et du Bassin Méditerranéen, Paris, 1901, 544 pp., illustrated. *Davatne, C.J. Recherches sur l’Anguillule du Blé niellé considérée au point de vue de Vhistoire naturelle et de l’agriculture, Mémoire couronné par Jl’institut 1857, 80 pp., 3 pls. Also in Comptes Rendus des Séances et Mémoires de la So- ciété de Biologie, Paris, 1856, ser. 2, vol. 3, pp. 201-271, pls. 1-3. 1857. Detacrorx, GEorGES. [Sur quelques maladies vermiculaires des plantes tropicales dues 4 l’Heterodera radicicola Greef.] L’Agriculture Pratique des Pays Chauds, vol. 1, 1901-1902, pp. 672-688; vol. 2, 1902-1903, pp. 80-88, figs. 1-2; pp. 135-143. Reviewed in Zeitschrift fiir Pflanzenkrankheiten, vol. 14, no. 5, November 1, 1904, p. 311. * Dorsett, P. H. New diseases of the violet. The American Florist, vol. 15, Sep- tember 30, 1899, pp. 246-248, figs. 1-5. Ducomet, V. Le dépérissement des bois de Chéne-Liége en Gascogne. Bulletin Mensuel de 1l’Office de Renseignements Agricoles, Ministére de l’ Agriculture [France], Paris, 7th year, 1908, pp. 288-299. Dyke, W. Root eelworms in tomatoes and cucumbers. Journal of Horticulture, London, ser. 3, vol. 35, December 9, 1897, pp. 547-548. *Frank, A. B. [Gallen der Anguillula radicicola Greef an Soja hispida, Medicago sativa, Lactuca sativa und Pirus communis.] Verhandlungen des Botanischen Vereins der Provinz Brandenburg, year 23 (1881), Berlin, 1882, pp. 54-55. Ueber das Wurzelilchen und die durch dasselbe verursachten Beschiadi- gungen der Pflanzen. Landwirthschaftliche Jahrbticher, vol. 14, 1885, pp. 149-176, pl.3. Die Krankheiten der Pflanzen; ein Handbuch fiir Land- und Forstwirte, Gartner, Gartenfreunde und Botaniker, 2d ed., vol. 3, Die tierparasitaren Krank- heiten der Pflanzen, 1896, chap. 2. GaLLoway, B. T. Club root in roses. American Gardening, vol. 18, February 20, 1897, p. 127. *GANDARA, GUILLERMO. La anguilula del Cafeto. Comisién de Parasitologia Agri- cola, Mexico. Circular 51, 1906, 7 pp., 6 figs. *GiLBERT, W. W. The root-rot of tobacco caused by Thielavia basicola. Bulletin 158, Bureau of Plant Industry, U.S. Dept. of Agriculture, 1909, 55 pp., 5 pls. *G6xp1, Emmio Avcusto. Relatorio sobre a Molestia do Cafeeiro na Provincia do Rio de Janeiro. Archivos do Museu Nacional do Rio de Janeiro, vol. 8, 1892, pp. 7-123, pls. 1 to 4, 1 map. 217 * * * 78 ROOT-KNOT AND ITS CONTROL. * Greer, R. [Ueber die frei lebenden Nematoden (Anguillulinen).] Sitzungsbe- richte der Niederrheinischen Gesellschaft fiir Natur-und Heilkunde zu Bonn. Sitzung vom 6 December, 1864, pp. 112-113. Verhandlungen des Naturhisto- rischen Vereines der Preussischen Rheinlande und Westphalens, vol. 21, 1864. * Ueber Nematoden in Wurzelanschwellungen (Gallen) verschiedener Pflanzen. Sitzungsberichte der Gesellschaft zur Beférderung der Gesammten Naturwissenschaften in Marburg, 1872, pp. 172-174. GvozpENovi¢é, Franc. Pflanzenkrankheiten und Schidlinge. Bericht iiber die Titigkeit der K. K. Landwirtschaftlich-Chemischen Versuchsstation in Spalato im Jahre 1902, pp. 8-10. * Hatstep, Byron D. Nematodes as enemies to plants. Report of the Botanical Department. Eleventh Annual Report of the New Jersey Agricultural Experiment Station for the year 1890, pp. 366-370. 1891. * Hays, W.M. Plant breeding. Bulletin 29, Division of Vegetable Physiology and Pathology, U. 8. Dept. of Agriculture, 1901, 72 pp., 6 pls., 21 figs. HENNING, Ernst. De vigtigaste 4 kulturvixterna férekommande nematoderna. Kongl. Landtbruks-Akademiens Handlingar och Tidskrift, Stockholm, 1898, vol. 37, pp. 247-265, 7 figs. Hieronymus, G. Beitrige zur Kenntnis der europiischen Zoocecidien und der Verbreitung derselben. Jahresbericht der Schlesischen Gesellschaft fiir Vater- lindische Cultur, vol. 68, 1890, Ergiinzungsheft, pp. 49-272. * Hoox, James M. van. Diseases of ginseng. Bulletin 219, Cornell University Agricultural Experiment Station, June, 1904, pp. 163-186, figs. 18-42. * Huerao, José M. (Hiso). Enfermedad radicular del tomate. Boletfin de Agricul- tura y Ganaderia, Republica Argentina, vol. 2, no. 42, 1902, pp. 1040-1059, 14 figs. * Enfermedad radicular de la vid causada por la Heterodera radicicola 6 Angui- lula radicicola de Greef (Anguilulosis). Boletin del Ministerio de Agricultura, Buenos Aires, May, 1906, vol. 5, no. 1, pp. 29-56, 13 figs. IacuLDEN, W. Combating eelworms and supporting plants. Journal of Horticulture, London, ser. 3, vol. 36, January 27, 1898, p. 76. * Janse, J. M. De aaltjes-ziekten van eenige cultuurplanten en de middelen ter harer bestrijding aangewend. Teysmannia, Batavia, vol. 3, 1892, pp. 475-488, 800-820. * Jopert, C. Sur une maladie du Caféier observée au Brésil. Comptes Rendus Hebdomadaires des Séances de 1’Académie des Sciences, Paris, vol. 87, 1878, pp. 941-943. * Kameruine, Z. Verslag van het Wortelrot-Onderzoek, Soerabaia, 1903, 209 pp., 19 pls. Krerrer, J. J. Synopsis des Zoocécidies d’Europe. Annales de la Société Ento- mologique de France, vol. 70, 1901, pp. 233-579. * Kinny, Junius, and Ligsscner, G. Bericht iiber Versuche mit riibenmiden Béden, welche im Jahre 1879 in mehreren Wirthschaften der Provinz Sachsen ausgefiihrt wurden. Neue Zeitschrift fiir Riibenzucker-Industrie, vol. 4, 1880, pp. L8. * Kitiun, J. Die Ergebnisse der Versuche zur Ermittelung der Ursache der Riiben- miidigkeit und zur Erforschung der Natur der Nematoden. Berichte aus dem Physiologischen Laboratorium und der Versuchsanstalt des Landwirthschaftlichen Instituts der Universitat Halle, no. 3, 1881, pp. 1-153, pls. 1-3. ‘ Die Wirksamkeit der Nematoden-Fangpflanzen nach den Versuchsergebnis- sen des Jahres 1881, op. cit., no. 4, 1882, pp. 1-14, 1 fig. bd Bericht iiber weitere Versuche mit Nematoden-Fangpflanzen, op. cit., vol. 2, no. 6, 1886, pp. 163-175. (1886-1.) ra Anleitung zur Bekimpfung der Riibennematoden, op. cit., vol. 2, no. 6, 1886, pp. 176-184, pl. 3. (1886-2.) 217 BIBLIOGRAPHY. 79 * Ktun, J. Neuere Versuche zur Bekimpfung der Riibennematoden. Centralblatt fiir Bakteriologie und Parasitenkunde, vol. 9, 1891, pp. 563-566 and 593-597. Laceruem, N. G. von. Baltiska zoocecidier. Arkiv fér Botanik, Upsaia, 1905, vol. 4, no. 10, pp. 1-27, pl. 1. * LAVERGNE, Gaston. L/’anguillule du Chili (Anguillula viale). Revue de Viti- culture, vol. 16, 1901, pp. 445-452, figs. 75-83. * Licopoul, G. Sopra alcuni tubercoli radicellari continenti Anguillole. Rendiconto dell’ Accademia delle Scienze Fisiche e Matematiche, Naples, 1875, vol. 14,pp. 41-42. Le galle nella flora di aleune Province Napolitane, Naples, 1877, 4 pls. * Lorsy, J. P. Eine amerikanische Nematodenkrankheit der Gartennelke. Zeit- schrift fiir Pflanzenkrankheiten, vol. 2, 1892, pp. 135-136. * Lounssury, ©. P. Gall-worms in roots of plants. An important potato pest. Circular 25, Cape of Good Hope Department of Agriculture, 1904. Maenus, P. Ueber Wurzeln von Passiflora mit kleinen seitlichen Verdickungen, verursacht von Heterodera. Sitzungs-Bericht der Gesellschaft Naturforschender Freunde zu Berlin, November, 1888, no. 9, p. 170. *MarcrinowskI, Kati. Parasitisch und semiparasitisch an Pflanzen lebende Nema- toden. Arbeiten aus der Kaiserlichen Biologischen Anstalt fiir Land- und Forst- wirtschaft, Berlin, 1909, vol. 7, no. 1, pp. 1-192, pl. 1, 76 figs. May, J. N. Club roots. American Florist, vol. 3, April 15, 1888, p. 396. * Eel worms affecting roses. American Florist, vol. 11, January 25, 1896, p. 649. *Mo.iiarD, Marin. Sur quelques caractéres histologiques des cécidies produites par l’Heterodera radicicola Greff.1_ Revue Générale de Botanique, vol. 12, 1900, pp. 157-165, 1 pl., 1 fig. *Mossert, Victor. La maladie vermiculaire récemment observée en Egypte sur les bananiers, betteraves, etc., causée par |’Heterodera radicicola (Greef-Miiller) avec une observation sur les Orobanches. Communication faite 4 1’Institut Egyptien au Caire, Cairo, 1903, 40 pp., 3 pls., 4 figs. * Muiier, Cary. Neue Helminthocecidien und deren Erzeuger. Inaugural dis- sertation, Berlin, 1883. Mittheilungen iiber die unseren Kulturpflanzen schidlichen, das Gesch- lecht Heterodera bildenden Wiirmer. Landwirthschaftliche Jahrbiicher, vol. 13, 1884, pp. 1-42, pls. 1-4. * Minter, Junius. Ueber Gicht oder das sogenannte Gichtig- oder Radigwerden (Nielle) des Weizens und anderer Grasfriichte. Bulletin du Congrés International de Botanique et d’Horticulture, réuni 4 Amsterdam les 7, 8, 10 et 11 avril 1865, Rotterdam, 1866, pp. 420-429. * Neat,J.C. The root-knot disease of the peach, orange, and other plants in Florida, due to the work of Anguillula. Bulletin 20, Division of Entomology, U. 8. Dept. of Agriculture, 1889, 31 pp., 21 pls. NEEDHAM, JOHN TURBERVILLE. An account of some new microscopical discoveries, London, 1745. - [Lettre en réponse au mémoire de Roffredi.] Observations sur la Physique, sur l’Histoire Naturelle et sur les Arts, par M. l’Abbé Rozier, vol. 5, 1775, pp. 226-228. ' * OLIVER, GEoRGE W. New methods of plant breeding. Bulletin 167, Bureau of Plant Industry, U. S. Dept. of Agriculture, 1910, 39 pp., 15 pls. * Orton, W.A. The wilt disease of the cowpea and its control. Bulletin 17, pt. 1, Bureau of Plant Industry, U. 8. Dept. of Agriculture, 1902, pp. 9-22. ¥ The development of farm crops resistant to disease. Yearbook, U.S. Dept. of Agriculture, for 1908, pp. 453-464, pls. 39-40. 1909. * 1The name Greef is misspelled, as shown in the title of the paper cited. 91294°—Bul. 217—11—_6 80 ROOT-KNOT AND ITS CONTROL. *OsTERWALDER, ApoLtr. Nematoden als Feinde des Gartenbaues. Gartenflora. Zeitschrift fiir Garten- und Blumenkunde, vol. 50, 1901, pp. 337-346, pl. 1488, 1 fig. Prauion, V. Malattia del Cyclamen cagionata da Heterodera tacdigiqalng L’ Italia Agricola, Milan, 1902, vol. 39, pp. 444-445, 1 pl. Queva, C. Modifications anatomiques provoquées par |’ Heterodera radicicola Miill. dans les tubercles d’une Dioscorée. Association Frangaise pour l’Avancement des Sciences, Paris, Compte Rendu, session 23, 1894, pt. 2, pp. 629-633, figs. 1-4. 1895. *Reep, GeorGE M. The development of disease-resistant plants. Second Annual Report, Missouri State Board of Horticulture, 1908, pt. 2, pp. 284-296. 1909. * RirzeMA Bos, J. L’Anguillule de la tige (Tylenchus devastatrix Kiihn) et les maladies des plantes dues 4 ce nématode. Archives du Musée Teyler, ser. 2, vol. 3, 1892, pp. 161-348, 545-588, pls. 1-10, 3 figs. Les nématodes parasites des plantes cultivées. Sixiéme Congrés Interna- tional d’ Agriculture, Paris, 1900, Compte Rendu des Travaux, vol. 2, pp. 306-312. * Rotrs, P.H. Report of the botanist and entomologist, Florida Agricultural Experi- ment Station, annual report, 1893. Bulletin 24, January, 1894, pp. 16-19, figs. 1-5. Mg Diseases of the tomato. Bulletin 47, Florida Agricultural Experiment Sta- tion, September, 1898, pp. 145-146. Ross, HERMANN. Beitrige zur Anatomie abnormer Monocotylenwurzeln (Musa- ceen, Bambusaceen). Berichte der Deutschen Botanischen Gesellschaft, vol. 1,_ 1883, pp. 331-338, pl. 10. Rupp, W. N. Killing grubs in soil. The American Florist, vol. 9, September 28, 1893, p. 171. Satmon, E. 8. On raising strains of plants resistant to fungus disease. Report of Third International Conference on Genetics, 1906, pp. 378-384, 2 diagrams. London, 1907. ScHLECHTENDAL, D. H. R. von. Beitrige zur Kenntnis der Pflanzengallen. (Sam- melberichte aus den Jahren 1884-1885.) Jahresbericht des Vereins fiir Naturkunde zu Zwickau in Sachsen, 1885, pp. 1-23, pls. 1-2. 1886. ScHroeDeER, ©. Das Stockilchen (Tylenchus devastatrix). Zeitschrift der Land- wirtschaftskammer fiir die Provinz Schlesien, year 6, 1902, pp. 579-580. *Setpy,A.D. Investigations of plant diseases in forcing house and garden. Bulletin 73, Ohio Agricultural Experiment Station, December, 1896, pp. 221-246, 4 pls., 5 figs. * Soil treatment for the forcinghouse. The control of rosette (Rhizoctonia) in lettuce and tomatoes and of nematodes in crops grown under glass. Circular 57, Ohio Agricultural Experiment Station, 1906, 7 pp. *SnHamet, A. D., and Copry, W. W. Tobacco breeding. Bulletin 96, Bureau of Plant Industry, U. 8. Dept. of Agriculture, 1907, 72 pp., 10 pls., 14 figs. *SHELDoN, Joun L. Nematode galls on clover roots. The West Virginia Farm Review, February, 1905, vol. 13, no. 2, p. 42. *Sorauer, P. Handbuch der Pflanzenkrankheiten, vol. 3, 1906. Spmiman, W.J. Application of some of the principles of heredity to plant breeding. Bulletin 165, Bureau of Plant Industry, U. 8S. Dept. of Agriculture, 1909, 74 pp., 6 figs. Strrt, A. Bekimpfung der Riibennematoden durch Ueberflutung des Feldes. Wiener Landwirtschaftliche Zeitung, vol. 53, 1903, pp. 621-622. * Ueber im Jahre 1907 veréffentlichte bemerkenswerte Arbeiten und Mittei- lungen auf dem Gebiete der Zuckerriiben- und Kartoffelkrankheiten. Centralblatt fiir Bakteriologie, Parasitenkunde und Infektionskrankheiten, pt. 2, vol. 21, 1908, no. 4-6, pp. 117-143. 217 * BIBLIOGRAPHY. 81 _*Sronz, G. E. Freezing, steaming and drying soil to destroy eel worms. The American Florist, vol. 15, August 12, 1899, pp. 32-33. * Stone, G. E., and Suiru, R. E. Nematode worms. Bulletin 55, Hatch Experi- ment Station of the Massachusetts Agricultural College, November, 1898, 67 pp., 12 pls. *SrruBELL,ADoLF. Untemuchungen iiber den Bau und die Entwicklung des Riiben- nematoden Heterodera schachtii Schmdt. Bibliotheca Zoologica. Original- abhandlungen aus dem Gesammtgebiete der Zoologie, herausgegeben von Dn Rud. Leuckart und Dr. Carl Chun, vol. 2, 1888, 52 pp., 2 pls. * Srureis, Wmu1AM C. Report of the Mycologist. Annual report of the Connecticut Agricultural Experiment Station for 1892, pp. 36-49. 1893. * TarRNANI, J. Ueber Vorkommen von Heterodera schachtii Schmidt und H. radici- cola Mill. in Russland. Centralblatt fiir Bakteriologie Parasitenkunde und Infektionskrankheiten, pt. 2, vol. 4, 1898, pp. 87-89. * TiscHLER, G. Ueber Heterodera-Gallen an den Wurzeln von Circaea lutetiana L. Berichte der Deutschen Botanischen Gesellschaft, vol. 19, 1901, Generalver- sammlungs-heft, 1902, pp. 95-107, pl. 25, and 1 text figure. * TRELEASE, WILLIAM. A nematode disease of the carnation. The American Florist, vol. 9, March 1, 1894, pp. 680-681. Trevus, M. Onderzoekingen over sereh-ziek Suikerriet. Mededeelingen uit ’s Lands Plantentuin, Batavia, 1885, no. 2, 39 pp. TROTTER, ALESSANDRO. Intornoa tubercoli radicali di Datisca cannabina L. Nota preliminare. Bullettino della Societa Botanica Italiana, 1902, pp. 50-52. Osservazioni e ricerche sulla ‘‘malsania” del Nocciuolo in provincia di Avellino e sui mezzi attia combatterla. Redia, vol. 2, 1904, January, 1905, pp. 37-67. (1905-1.) - Nuove osservazioni su Elmintocecidii italiani.’ Marcellia, vol. 4, 1905, pp. 52-54. (1905-2.) * Voret. [No title.] Sitzungsberichte der Niederrheinischen Gesellschaft fiir Natur- und Heilkunde in Bonn, May 12 and July 7, 1890, pp. 66-74 and 93-98. Verhand- lungen des Naturhistorischen Vereines der Preussischen Rheinlande Westfalens und des Reg.-Bezirks Osnabriick, vol. 47, 1890. Warminc, Eve. Knolddannelser paa Rgdderne af Elymus arenarius. [In “‘Smaa biologiske og morfologiske Bidrag.’’] Botanisk Tidsskrift, Copenhagen, 1877-1879, ser. 3, vol. 2, pp. 93-96. * Wesser, H.J., and Orton, W. A. A cowpea resistant to root-knot (Heterodera radicicola). Bulletin 17, pt. 2, Bureau of Plant Industry, U. S. Dept. of Agri- culture, 1902, pp. 23-38, pls. 5 and 6. Witcox, E. M. Plant breeding to secure resistant forms. Bulletin 123, Office of Experiment Stations, U. S. Dept. of Agriculture, 1903, pp. 117-118. * ZIMMERMANN, A. Het vorkomen van Nematoden in de wortels van sirih en thee. Teysmannia, vol. 10, 1899, pp. 230-236. * S De Nematoden des Koffiewortels II. De Kanker (Rostrellaziekte) van Coffea arabica. Mededeelingen uit ’s Lands Plantentuin, Batavia, no. 37, 1900, 62 pp., 21 figs. 217 DESCRIPTION OF PLATES. Pirate I. Stagesin the development of Heterodera radicicola (Greef) Miill., etc. Figs. 1 and 2.—Eggs in two different stages of development, X 350. Fig. 3.—Larva immediately after escaping from egg, X 105. Fig. 4.—Anterior portion of same, X 410. Figs. 5 to 8.—Developmental stages of larvee before sexual differen- tiation is apparent, X 105. Fig. 9.—Molt in which sexual differentiation first becomes apparent, female nematodes approaching sexual maturity, X 105. Fig. 10.—Sexually mature female nematode, a somewhat more advanced stage than shown in figure 9, X 105. Fig. 11.—Posterior portion of sexually mature female nematode somewhat compressed, X 220: a, Anal opening; b, alimentary canal; c, genital opening; d, vagina; e, e, uteri; f, f, ovaries. Fig. 12.—Egg- bearing female nematode, X 47: a, Alimentary canal; 6, loop of uterus; e, genital opening. Fig. 13.—First visible stage in differentiation of the male nematode (compare with fig. 9), X 105: ¢, t, Testis. Fig. 14.—Mature male still within larval skin, X 85. Fig. 15.—Mature male, X 85. Fig. 16.—Anterior portion of adult male, showing spear and peculiar structure for guiding its movements, X 930. Fig. 17.—Larva entering root of clover, X 100. Fig. 18.— Larva of Heterodera schachtii Schmidt just escaped from egg (compare fig. 3), < 105. Fig. 19.—Anterior portion of same, < 435. Prats II. Fig. 1.—Root-knot on sugar beets grown at the Subtropical Laboratory, Miami, Fla. 1907. Photographed by E. A. Bessey. Fig. 2.—Root-knot on squash, from Beeville, Tex. 1904. Photographed by W. A. Orton. Puate III. Fig. 1.—Root-knot on carrot, from Morrison, Ill. 1908. Photographed by W. W. Gilbert. Fig. 2.—Root-knot on red clover grown in a pot of sterilized soil inoculated with affected roots of Ipomoea ‘syringaefolia, Subtropical Labora- tory, Miami, Fla., 1908. Photographed by E. A. Bessey. 217 82 Bul. 217, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE I. STAGES IN THE DEVELOPMENT OF HETERODERA RADICICOLA (GREEF) MULL., ETC. Bul. 217, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE Il. Fic. 1.—ROOT-KNOT ON SUGAR BEET. Fic. 2.—ROOT-KNOT ON SQUASH. i Bul. 217, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE III. Fig. 1.—ROOT-KNOT ON CARROT. Fic. 2.—ROOT-KNOT ON CLOVER. Page. eeies., Or Control of root-lkmot. - ...\5.< 2: s25- Jes el See 8 55-56, 76 MinessGennan Hast, occurrence of root-knot...----...5.s2s25te00 tens See eske 23 GECMELENEE OL LOOU-KMOUS, a2:.5 2.5) 5 yan eicyeieleranis BRS 23, 25, 38, 42 Puraieocenrtence Gt TOOt-Knots <2 252 Sb 2 noe Se Oe 23, 38, 42 Agrostis alba. See Redtop. Airacondiilons favorable to:root-kmnot: 22. Bisbee Sos a hee es eee 42-44 See also Moisture, and Temperature. eee renee: Of TOOt-KNOt. <-. 42 ..sec22 e220. 02 deel see: 23, 64 Micmanara, Va, investigations of root-knot:....J5v::21.6225-.005 00 co. eee bac. 47 Mimiameuncentibility tO TOot-kNOt.......-.--s--.252se------ 202 eeeee 17, 24, 43 re mamecanErence Of TOOL Knots. ut). soastedee 2 he)... onle lie. ke 23 Rmsetninus pp., Susceptibility to root-knot......- 2202... 5..6-028 Ub ee cee 12, 69 Ammonium silicofluorid, application for control of root-knot...........-..-.--- 55-56 sulphate, application for control of root-knot..........---- 54-56, 57, 58 Andropogon spp., susceptibility to root-kmot...............--.22.-2---2--2--- 12, 21 Anguillula spp., synonyms of parasite causing root-knot.............-------- 8,9, 71 mins, Aeekey in spreading Toot-kmot...5. 2.5 .2-2s5-5--4.---5 39.01 Melosh e 38, 73 PeeRenMn ma Vata liny ests. 2c. o2 . - od ede boy cede ee ese lk Le LG 30 MpPeeiscemimtbiiiy tc LOOt-KNOt..2.. =2\s2e sien -22U see olen eee SS 17, 24 Miainnanacererence Of Toot-kKnot. -......25 2222232 0.2290. 2 Fie ke ee ee. 23, 42, 61 ATIZGnaANoceurrence OL TOOt-knote../6$2.) 2.606 Je Se Sok ive ek 23, 24, 38, 42, 49, 59 Arlcinisan Ore NITeENnce Of TOOt-kKMOt. =< =. 2 Ue. oo. eae ee eden oe hee Avie eae 24 RECS ELONCe Of TOOtKN Obs. asecice 32-2 iva Sue ee es Oa ee. 23, 25, 49 Bepaeeaeiiceptibility to root-knot...s..22..0024 ves.0 2.22 beetle eed 12, 38 Atkininons GH, on root-knot........-<:---.- Se TaatG, 17. 18119,'20, 32135, 36,16 AVIS LOCCUFEENCE OL TOOt-KNOt-0: 222202002. 8b 2 ed Se see ee oe ge beet 23 Upto OCe UEreNnee: Of TOOt-KnObIs2 seb so OL OR oe Sk ocd Oe 23 Bailey, L. H., on methods of control of root-knot............-------------- 43, 72, 76 Bakerene von occurrence. omnematodes... (2 .c25-.-s2h cee ---. ee See 12, 39, 40-41, 52, 57, 61, 82 tiredness, disease due to Heterodera schachtii.............---.-------- 61 Beggarweed, Florida, resistance to root-knot.........--...------- 17, 65-67, 69, 70, 74 Berkeley, M. J., on occurrence of root-knot.......----.---------------- 8, 14, 23, 76 Perey As, investications of root-knot-2/! 222522222220 92..- 22.2.2 2 Peierpy partial, of root-knot.......-22.02229_) 29... 2 eb. f 22 2 76-81 Peace ress cecctance to root-knot: =; 2... 22-22-.-. 22 e ss... 2 et 21 ironman name tor TOOt-KNOt=ss....00 505.252 tel ee aes 5 eR LL: 7 Bouquet de la Grye, on susceptibility of Coffea spp. to root-knot.-..-....--- 14, 71, 76 Peete Meearrcnco Onroot-knot i662 22 255 ct. Ree 9, 23, 49 Breda de Haan, J. van, on root-knot.............-- 11, 12, 13, 14, 16, 17, 18, 19, 54, 76 Breeding. See Root-knot, breeding resistant strains. iencleweememiacenrrence of root-icnot.......2222)s0. 0. MISTY: lee eee 16, 76 Bromus schraderi, resistance to root-knot.............-.....-----s----+---- 21 Calcium carbid, use in experiments for control of root-knot..........-------- 51, 54 Gaiifornia, occurrence of root-knot............------.----2--- 23, 24, 36, 38, 42, 49, 59 Cane, sucar, susceptibility to root-knot.......-.-2.5.002-0222----2.202.205-- 8,19 217 83 84 ROOT-KNOT AND ITS CONTROL. Page. Cape Colony, eecurrence of rovt-knot.....5. 22.2205. ce et one soe- eee 23 Carbon bisulphid, use in experiments for control of root-knot.. 47, 49-50, 51-52, 53, 74 Careless weed. See Amaranthus spp. Carrot, suscepliibility to root-knot ~~... 6... 4002200 sas sn en nen uo abe 14, 82 Casali:'C:, on occurrence of root-knotice os eqs ee = 2 ne oe se oe ee 14, 76 Catalpa, susceptibility to root-knot: 22. 605.0, 2.2.05. -..,..- soso eee 13, 22 Ceylon, occurrence of root-kKnot ....- =< 2,. «cn «anaes sess de enone ee eee 23, 49 Chambers, W. E., drawings illustrating root-knot nematode.................-- 28, 29 Chemicals, use in experiments for control of root-knot.......-.. #.-- 49-52, 53-56, 74 @hitlot,J., on, occurrence of root-knot........-.- <2... 200 5ecee ae aoe ee ee 14, 76 QOhile, occurrence of root-knot.......... isGdebesk 12 eee a ae 9, 23, 42, 61 Ohiaa,occarrence of root-knot..... ... ....-..---....2.200n ant eee dS ee 23, 25 OClimeie, relation to. roct-knos...\....... - +... - beet dS. 21 SI 24, 42-44, 48, 73 Clover, Japan, resistance to root-knot...........-..--~---JOCLONL SDE, . 16, 69 Mexican, employment for reduction of root-knot.....................- 69 species resistant to root-knot . . ......: «zis ceLint de 63, 69 susceptibility to root-knot..............---...----..-- 16,17, 20, 22, 43, 69, 82 @lub-root, variant name for root-knot.....2s00. $505-i. 60s cee see es 2 8 Geile. A. on yoot-knotr. 6. kee eens ree 9, 12, 19, 20, 28, 35, 38-39, 42, 61, 77 Cobey, W. W., and Shamel, A. D., on strains of tobacco resistant to root-knot. 71, 80 Coffee, susceptibility to root-knot.......-.....-..----..-5.--- 9, 14, 49, 50, 60, 71, 75 Colorado, occurrence of root-kmot... i222. 2224 5.)3 122 Jc 6 24, 40 Connecticut, occurrence of reot-kmot: bs Ji tiises 42/2 GU eee Oorn, Indian, resistance to root-knot.......i4<).2c-0) 4J._.b2 e288 ee 21-22 Cornu, Maxime, on occurrence of root-knot...........- ...- 8,14, 16, 17, 19, 20, 21, 77 Cotten, relation to root-kniot......- =. -.-.2.2....«J0seu does SSE Be ee 15, 66, 67 Cowpea, relation to root-knot..........------- 21, 22, 23, 54-57, 62, 65, 66, 68-69, 70, 71 Orab-erass, susceptibility to root-knot.....-.-..... side 6.0) 4s 21, 65, 69 Cramer, P. J. S., on occurrence of root-knot.......is2s:055. 524... Eee 14,77 Crops, nonsusceptible, rotations for control of root-knot ...........--.---.- 65-69, 74 perennial, root-knot, control in field......... -sxi2=250. bh: 2)eeeee 48-52, 74 trap, use in control of root-knot......-......-...2sus-3.20! 3 61-63, 75 Queumber, susceptibility to root-knot.....-.....2cc4she-1 6) 2h DI 14, 22, 59 Dalla Torre, K. W. von, on occurrence of root-knot.........-......-1.--.--- 12, 19, 77 Darboux, G., and Houard, C., on occurrence of root-knot........--- 13, 14, 16, 19, 77 Davaine, C. J., on occurrence of nematodes...-........-.-----..a:s5s=e eee 30, 77 Delacroix, Georges, on occurrence of root-knot....-....-..--------------- 17, 18, 77 Delaware, occurrence of root-knot...--..:.-- 4ysic8626 Us eee eee 24 Dorsett, P.,H., on occurrence of nematodes .U..2 ~j20)-Le asec eon Beoe ae 30, 77 Drying, effect on root-knot, investigations... - . 30, 37-38, 42-44, 45, 48, 60-61, 73, 74, 75 Ducomet, V., on occurrence of root-knot.. !o..20 . 2202-222: ss: - SEE 19, 77 Dyke, W.; on-control of root-knot ....--.--.:22-.s0-. s2t)e-: 26: eee 56, 77 East Indies, eccurrence of root-knot-..-.---jo:cb so: +). vahisieeeaeer es 23, 25, 49, 54 Echinochloa frumentacea. See Millet, Japanese. Eelworm, variant name for nematode causing root-knot.......-....---------- 7 Egg of root-knot nematode. See Heterodera radicicola, egg. Egypt, occurrence of root-knot.....-..-----2--/:--+----+- 2202-2255 2-seseneae 23 Elm, European, susceptibility to root-knot..........---.-------+--+-+---+-++- 20, 39 England, occurrence of root-knot...-.. - ~~. 25 -m 55. be seece =e Bee = 23 Escobar, Romulo, on root-knot infestation of watermelon........---.--------- 40 Euchlaena luxurians, resistance to root-knot.....-.--.------ .. Jot See 21 Europe, occurrence of root-knot.......-...------- 22 -e-2 0%: $4-e2==5==== 4 eee 23 European elm. See Elm, European. Eustachys petraea, unaffected by root-knot .........-..-..----+-----++---+-+---- 21 Everglades, occurrence of root-knot.......--..----------<04 42-«-+- ss s==== eee 42,59 Experiments, cross inoculation, for testing adaptation of root-knot nema- LODO o20 occ nen can nee eee <= onic 2 step ate bie Sess mye epee pee eee 22-23, 82 See also Root-knot, methods of control. Fallow, bare, use in control of root-knot............------------------- 64, 69, 70, 74 Fawcett, G. L., on root-knot infestation of the coffee tree. .....---.---------- 75 Fertilizers, use in control of root-knot in fields.........--...-.---- 52, 56-58, 70, 74-7 Fields, root-knot eradication and control ...........0------------5+--e 48-71, 74-75 217 INDEX. 85 Page. ipetelilion to root-knot..00255 253s scc2 ees 15, 22, 23, 24, 36, 38, 49, 71, 73 Flooding, method of control of root-knot.................---- 42, 52, 58-60, 70, 74, 75 Florida beggarweed. See Beggarweed, Florida. MesnecHee Of KObt-kNOG. 2225 2 2395395 9SES eee Ee OE, 9, 11, 28, 25, 31, 35, 42, 43, 49, 51, 53, 57, 59, 60, 63, 64, 73, 82 root-knot investigation. See Miami, Fla. Formaldehyde, use in experiments for control of root-knot. - - 46-48, 50-51, 53-54, 74 Formalin. See Formaldehyde. France, experiments for cancel or paylloxerd$ -2245 2792 Rt 54 occurrence of root-knot........- PARLE Se) BAG NS SE NTs RAS Snes Mes a 23 Frank, A. B., on root-knot.............---- 8, 12-20, 26, 37, 40, 41, 42, 43, 60, 62, 63, 77 Freezing. See Temperature. Seaway. is 1 -, On occurrence of root-kmot-. 22222. 22) oh. ane = - 2 oo ames 44,77 Gane, root-knot, depth of occurrence in soil-....- 52.2. ee 41, 52 HRSG TMGIRTOTY. N22 5 920 tS St MOS Se no eee Site al 7-8, 39-41 eamunie, G. A., on occurrence of root-knot....... 22.2... a2 22-222 i 16, 17, 20 Gandara, Guillermo, on occurrence of root-knot...............--- 18, 50, 51, 54, 61, 77 Gardens, in Florida, root-knot investigations...............- 9-10, 31, 43, 51, 58, 55, 82 Seem tam ec Utrence OF TOOt-KMOt. ..... 2. oc biemes Se fate eera!a)s fire elon ete 23, 59, 64 German East Africa. See Africa, German East. Germany, occurrence of root-knot or other nematodes............. 8, 23, 26, 52, 57, 69 ieimethewW. W., Ol studies of root-knot........- 2 -2-.-- + toctoh Sect oak - 63, 77, 82 Ginseng, occurrence of root-knot...........------.-+ssssees eee. 18, 22, 24, 38, 43, ie Gnaphalium purpureum, resistance to root-knot..........--...-------.------ eat oe A, O TOOL-KnOoL parasite ot collee..-- 2... 22-2...22--- 2. 0c ese ee 9, 60, e (una, felation. to.control of root-knot......./-..-iS0 dl es. . ele ee. 21-22, 74 See also Barley, Corn, Oats, Rye, Wheat, etc. Guia erecn,, susceptibility to root-kmotis:<2=)242.f2 ses eee oe Es ne 18, 22 Grapevine, relation to root-knot.........-.-...--- 21, 22, 23, 24, 36, 38, 49; 59, 61, 71, 73 Grasses, relation to root-knot..............-.---.-.-- 8, ut; 12, 13, 14 15, 18, 21, 65, 69 Greef, R. pon.oceurrence) of root-knot= 5224 ...222 2602 Jee 0 8, 1, 15, 18, 19, 23, 78 Greenhouses, methods of control of root-knot............--------...-- 9, 24,4448, 74 Gvozdenovic, Franc, on occurrence of root-knot................2.22.22--4---- 13, 78 Paleed..—...)., on occurrence of root-knot. ......-.--s:a- 2-21.42 22h. 12, 19, 21, 78 Hawkins, L. N. OH occurrence of zoptzksiot ii). 28s oS: 2 2cebeao bles 75 Hays, W. M., on Blan Preemie 2 oe a facie. POSTEO SERIE TCE S 72,78 Helenium tenuifolium, resistance to root-knot........--..---+0s-sssssssee ees 21 Henning, Ernst, on ee ices est, Site RM, ihren Pb OE 18, 78 Heterodera javanica, synonym of H. radicicola...:.2idl e222 222228 Sec ee kk 8-9 radicicola, cause of root-knot, life history, effects, etc... -. 25-41, 72, 82 Ce EMeSEDL ON cos) 2 ee 2 oe eee 26-27, 73, 82 larva, description and habits................ 27-32, 34, 73, 82 mature forms, description --2--2-- 5.5502 32- 36, 82 measurements of eggs, parts, Tee "26-29, 32- 35, 37 mole eae iis: Se wear 0) oe 31-32, 34 82 oricinall home: 2552261. ae oe Le ae! 25, 72 Ov erwintering HS, SRY SE IE! Seana es 2 OR DN a as to 36, 73 similarity to NEL echachitits it 16 M221 8, 27, 35, 36-37, 40-41 SY LLOMY TY eo jase. 5 bes eS oe oO Pe 8-9 See also Root-knot. schachtii, cause of disease of the sugar beet................----- 8, 25, 27, 35-37, 39, 40-41, 52, 57, 58, 61, 82 Pacemananiiec ON COOt-KMOL.>--.-< va. ... sees se ae eee ee 23, 40, 49, 61 Miami, Fla., root-knot investigations............---------- 9-10, 31, 48, 51, 53, 55, 82 Michigan, occurrence of root-knot.:........-.----------------+---- 2-28-22 24, 43 Millet, Japanese barnyard, resistance to root-knot....-...-------------------- 21 Millets, susceptibility to root-kmots........------..-----22---2--+s-<05 =e 13, 15, 21 Milo, resistance to root-kmot. --. 22-22: 022.4... estan sees 2 =e ee Mississippi, occurrence of root-knot........----------0--2--220--22 5225s bees 23, 64 Moisture, effect on root-km0t.\- 24.242. 2. s)) feeete Sct Saat ee 4s J ee 42,73 See also Drying and Flooding. Molliard, Marin, on occurrence of root-knot.........------------------------ 12,79 Molting. See Heterodera radicicola, molting. Monetta, S. C., root-knot investigations............-- 9-10, 43, 53, 54, 55, 56, 62, 65-68 Morning-glory, tree, susceptibility to root-knot....-..-.------------------- 16, 22, 82 Mosseri, Victor, on occurrence of root-knot......-..-..----------------- 13,/16, 195,79 Mulberry, susceptibility to root-knot.........-.--..---------------- 17,24, 38, 49, 73 Muller, ©. ; O0 TOOL-KMOUs.. cence ce ee so eccuecesemeens sans aha se ree 8, 14, 17, 26, 79 217 INDEX. 87 Page. Miinter, Julius, on occurrence of nematodes.............--------2-0-0- ee eee 30,79 @ekmolon, susceptibility to root-knot: .--\..- .. 222i 4 ate ns Pass ws eI 14, 22, 59 Meio ee Crs, Gt, OCCURENCES OF TOOt-KMOL..< ...< 15 5/5 = ose ane tesa tee ~'e 9-21, 25, 69, 79 MR OCCUTFENCE OL TOOt-KNOL. .. . ~~ . 22-7 = - Sys HER . DEPARTMENT @2*ACRICULTURE. BUREAU OF PLANT INDUSTRY—BULLETIN NO. 218. B. T. GALLOWAY, Chief of Bureau. CROSSBREEDING CORN. BY C. P. HARTLEY, ERNEST B. BROWN, C. H. KYLE, AnD L. L. ZOOK, Office of Corn Investigations. IssuED Fresruary 17, 1912. i 3° a ae 9d » Me Se WUtysssso> WASHINGTON: GOVERNMENT PRINTING OFFIOE, 1912. BUREAU OF PLANT INDUSTRY. Chief of Bureau, BEVERLY T. GALLOWAY. Assistant Chief of Bureau, WILLIAM A. TAYLOR. Editor, J. E. ROCKWELL. Chicf Clerk, JamEs E. JONEs. CorRN INVESTIGATIONS. SCIENTIFIC STAFF. C. P. HARTLEY, Physiologist in charge. Ernest B. Brown and C. H. Kyle, Assistant Physiologists. L. L. Zook, J. G. Willier,and Fred D. Richey, Scientific Assistants. LETTER OF TRANSMITTAL. ~ U.S. DEPARTMENT OF AGRICULTURE, BurEavu oF Piant INDUSTRY, OFFICE OF THE CHIEF, Washington, D. C., August 14, 1911. Sm: I have the honor to transmit herewith and to recommend for publication as Bulletin No. 218 of the series of this Bureau a paper by C. P. Hartley, Ernest B. Brown, C. H. Kyle, and L. L. Zook, entitled ‘‘Crossbreeding Corn.” This article presents one feature of the work of the Office of Corn Investigations on the project of finding and developing higher yielding strains of corn for different geographical sections of the United States. The success that is being attained along this line is due to the utilization of the effects of acclimatization, adaptation, crossbreeding, and selection. The results of field tests in four States are given in detail. In this report the results are assembled in a manner to show the rela- tive productiveness of first-generation crosses and their parent varieties. While these results include a part of the data that are being assembled to show the effects on corn of acclimatization and adaptation, only such mention is here made of these influences as will prevent their effects being attributed to crossbreeding. These investigations assist in determining what varieties and what combinations of varieties can be most profitably grown in different localities. They also assist in revealing the qualities of seed corn that influence its productivity. Knowledge of this nature is espe- cially needed at this time to assist in establishing successful methods of corn improvement embracing the good effects of selecting fine- appearing ears and of crossbreeding, without leading practical corn growers into the belief that prize-winning ears are necessarily profit- able seed ears or that a well-selected and well-adapted variety is usually less productive than its first-generation cross. The results presented here are the first results of a series of tests being conducted with many varieties under various environments. More work more accurately conducted is necessary before general conclusions of a positive nature are warranted, but the urgent need of facts concerning our most widely grown and most valuable crop makes it advisable to publish in detail these results, which are at once of both local and general value. Respectfully, B. T. GaLLoway, Chief of Bureau. Hon. JAMES WILSON, Secretary of Agriculture. 218 3 er SATUIMCARAT 40 aria, " ee ad Sarno” vo Taner 2 B rereden read wo vanavel asa) srr aor aorreO FLOS BY ferns BD. AL cco perintanl braces 0) baa dtirinoed sintanet of. roa0d oft 6 vase. «dt Yo este sit Yo BIS ct nsolloll wa J al bas atv OO ermal A tom ,waltrabt ts am pyevenn albitia aif T “ire noibeordeeat” Sontony edit 1 aonagites’ rel erro”) to offi ark? to re: jitstib rot mos lo acierta gcibloiy tadyid gaiqolevab et teitt aassnie afl aatatc Letio’T od? lo enone ginatie edt bo noitesilite nit of ash ot om anit som nurtgolse bos ptr AT? . pokatae al WATal i torr iS 4in eotase uot nt ajeat br te. aley oli Ww ida OF WsAmROT # é beldiv@ens ota ef lowe firieq theds bre aaete ctubherent ertireto ny) wm todt alab wl) Wa Hq Sahin aliens dead Bae coilexitantiicow fo Tres etoelto elf woda of at a ais nial saat Yo ebant aed af SLY TOT dows Mins guiboord oT OF be HESITANT H,, Site dad, ej +olie tind 4 trrnkw bi zattahoy fede sonia tats ih Jaleas etabe. Saori ut mwoMm videsiioni Ants od ie meat Det A Ww mio bene yo weitiletp sol: gotlerto ai,daman aga a dia woties et orotuce itl to sebabwondh ° -irrhisneng “phadlient litteesoone “rtileidetes of Jee OF ond atdd & -suit gcitoalsa to atsete boo ait paiserdars taqgay mio lasiioany pathapl tie thie nitibasrdaaors to baw ohio ‘IPTAeaAoody Pie. iets srtirrnd r-ostia jads fotlod or " Ja #4 Visits ty parin low him hatoalioe thaw & ted? 0 eto COLE marae att gad? sviforbhoraa wiant to aacTaa A to erie derit aunty aia atest Dest sorevegy ¥f : SOOT iS. Att OPay s hats nattorigt FA diy ee. latsnen sioted queens: oct af betoubaoe item oba been tasnu act fod Seicerae om orien. OTTO Me io’ 171 suctusting ja ity LS FRWOTS viebhre Tent “10 . in ova sloth .etluet: seed) limtoh at slaty Oo anlar laractes hoa | reteatn #2 7 ‘ un . ety ys Td. Le - “ky noua aitiveneny ty Weg ~, CONTENTS. “es jer pd FELeLT OILS Gs See SO yc ae ee AE pw ee mee teen ees pA Tests in ey ie Be ad ee BR Ie ee ae: ke Ae RE See EE Ay es See oc Vaid SOE ICU Oe Ee ee ae es eee ee 2 ee, ee ee ee ee ee OS ee Prone ithe wariebieg. 2 6.2 SPS: ao os soa lien que sae Growing pure-bred seed for comparison.............-.--------------- Denton Rare (ees Shc aw cto arc ace win ore Vat cage ee oe Pirdero: planting the test TOWSs. << 2). a). oS eomet ob Senet Equality of conditions for growth and productiveness...........----- Praeniation of results in Maryland). ..12. 34:6.0.34245-0-,.jat-* ase - eid records in detail). 2324.20 o.. 25520 soe 2 a teeta ae- Comparative productiveness of seed of 1908 and 1909.....------------- Crosses compared in productiveness with the male parent.....--..-.- Combined results of the four Maryland tests...........--------------- PieiwaritaCeOUs CTOSSES <<. .< a use Seep sais Sa seeps speedos ae = Paoaewantateous Crosses: =. . sia. seee.. seer es Ho dee oe moaamicic re Comparison of first-generation crosses with the 1908 seed of both parents. Relative grain production of parent varieties and _ first-generation TT a er eS eee Beer. oe etre Stover weights of parents and crosses compared.....------------------ DPE MEEe aL Cmleo Cale, 1910-.2 2 sas. cesc ssc as oe soe 2} Segoe ae ee PERI HE GE EME VES s so < Mahe. See Stee oes een Set as MS EE ee Comparison of crosses with parent varieties.......-- Relation of adaptation and yield of parent Sarctee to ‘the behavior oe the ei eae ee te oS is Sah alan dias ema emis Tests in "Raa eae nah he ob Ga) De ces IR Be nS My Ss 1 eM sapere los aaah ViNirasal le oVe THOU Cry eters ade ae elie Lg ON ile OT Alec fo Ro a br et ea ere ah gS Nara OL): aed Se cece ene. EM 5 SMEAR Si TE) CS OE ee ee ee Tests at cet ai Shenmanic hex 5. seaase bed a oeee hens). beh aecide weremisg=t- Boat wait Wacod ex. Jochen Sacco oh decenaa-ebeetie eiaslt seeds Rosiaidtormesna s Vem. 126... Ba oo eines es = a= - soe 4a ae The three Texas tests considered collectively......------------------ The productivity of the parent varieties and its influence upon the productivity of the crosses. ............-----2---- eee cece nents eeeee rit aaotor Gd eer, were teat soe 98 Wee 55. nes oc n wns s Wartecties used.in the experiments. .........2.5--+----.----5-52--5-+550 218 IM nr ehwROnectiONt seeke ns sree fare ei oe iy nee = 26.5 Cita ae See MINICOM OLE Coe ee er ae eee eed St nto are mere Seen MC HIPOTOSEROMITC see so tee ree eins Soren eee an Se tae Menpyteralitie: 52 S06 2s. e fae. 0h. LSS ee Soa. 2. . Ree Nartincotoies tatesborosee oo Sticen.od od Hoey Soe ieee BS ace esi ete Bisdeers: Waite, Dei sois6 oa. sels <2 BS od bee erie sel alanine em x alli Grape rouse eee ee os hic, 5 chee slo osc ae es ee ca seem ero 6 CONTENTS. Tests at Statesboro, Ga.—Continued. Varieties used in the experiments—Continued. Page. Gisitdon Yellow... 220.4. .22 sanncauenp ale erue acme wees wee ann 43 pc oe err neha R SE 44 Witebetiely ca ape eiceing oa'e dtc cnunm ohm whee Beene oe he en 44 Williarspeat : 2 ooo) os 2 ote ge Agee eps Petes oo nce Sn 44 Work of 100-5. oo eae in re hoe ie ep cae ec eects nae 45 Character of the B00 ss . 6.2 «nip scnamdamans .£2275.2022 25. 2.2 ee 63 Inferences drawn from the foregoing data...........-.-.....--------- 63 General ‘consideration of all'the tests... ::iic222222222 0-2-2) ee 64 Indications of Intermediacy-~. 0.2 S22 ios. eee ees) ot eee 64 Percentage of moisture in shelled grain of crosses and parent varieties... . . 65 Unreliability of averages for specific instances........-.--...----------- 65 Index. 2522. 2222S SSSee Se eee ee ee eee ae 69 LL LEST Ea ae Page. Fic. 1. Diagram showing the relative production of parent varieties of corn and their first-generation crosses in Maryland, 1910.------......-..-------- 22 218 B. P. I.—668. CROSSBREEDING CORN. INTRODUCTION. In the United States corn has become the leading and most uni- versally grown crop, perhaps more because of its natural adaptability and productiveness than because of any improvement of the plant intentionally accomplished by man. Human efforts have doubtless had a great influence upon the evolution of maize, and it has been modified so as better to meet human needs. These changes, how- ever, have come about probably more because of the interdependent relations that have existed between man and corn than through knowledge intentionally applied. The evolutionary steps that have developed the maize plant as it exists to-day are so little understood that they are of little value in indicating methods to be adopted or avoided in further improving this crop. Such improvement may rest upon a close study of the effects upon the plant of different methods of breeding and a correct application of the principles evolved. The success of the work of the Office of Corn Investigations in originating and improving high-yielding strains of corn for different sections of the United States has been due to the utilization of the effects of acclimatization, crossbreeding, and selection. Of these three factors crossbreeding is the principal one here under considera- tion; but as these as well as other factors—such as seasonal and soil conditions—usually operate together in influencing plant growth, the effects of all factors that can not be eliminated must receive consideration whenever comparisons are made. Because crossbreeding of corn is so readily accomplished, and the results are so varied and interesting, and because crossbreeding is so generally recognized as a very important process in plant improve- ment, the corn investigations of the Department of Agriculture during 1900 and for several years following consisted very largely in crossbreeding all types obtainable. Of the first-generation crosses tested some were unusually productive, some good, some indifferent, 218 7 8 CROSSBREEDING CORN. and some unusually poor producers. ‘The indifferent and poor-pro- ducing crosses were discarded and selection work started with the unusually productive ones. As the work progressed some decreased in productiveness while others retained their high-yielding qualities, and a few have come into general culture as the best grain-producing strains of certain localities. As most of these crosses when tested in various localities were found to be seldom superior to local strains, the improvement of local strains by selection or by crossbreeding and selection com- bined became a more prominent feature of the corn work. This feature has proved highly satisfactory and profitable to practical farmers, and much experimental evidence has been obtained to demonstrate that strains can be greatly increased in productiveness by centgener selection. Investigations and observations have indicated a number of lines for the improvement of general practices in seed-corn production. In this connection attention is called to the following points regarding corn: (1) That self-fertilization reduces productiveness; (2) that constant isolation, especially when unaccompanied by judicious selection, may result in the multiplication of undesirable individu- als and the augmentation of their undesirable characters; (3) that the emphasis which has unfortunately been placed upon the possi- bility of improving productiveness by planting fine-appearing, prize- winning ears has reacted against the improvement of yields through the selection of seed from high-yielding individuals; (4) that the adaptation of the floral parts of maize to facilitate crossbreeding has played an important part in its evolution, perhaps assisting in giving it greater vigor, productiveness, adaptability, and freedom from disease than other cereals. One or more of these features has reduced yields in so many instances where increased yields were expected that some, and espe- cially those who have not witnessed improvement by selection, have become skeptical regarding possibility of increasing yields by selec- tion and desirous of trying radically different methods. Crossbred seed frequently gives .better yields than either parent, especially if one or both parents are poor producers as a result of self-fertilization, inbreeding, or lack of adaptation or acclimatization. Since crossbred seed corn frequently yields less than one and some- times less than either of the parent varieties, it would be very unwise to advise the general planting of crossbred seed without first demonstrating what varieties should be crossed in different localities to produce seed of higher yielding power than that of the best existing strains. The profits that may result from following 218 TESTS IN MARYLAND. 9 reliable methods and the losses that may result from following erroneous methods along these lines are tremendous because of the great extent to which corn is grown. As acclimatization, crossbreeding, and selection have proved effi- cient in increasing the productiveness of corn, the question of practi- cal importance is a determination of the best combination of these influencing factors. All these factors necessarily have a strong bear- ing upon the results presented in this paper. These results are pre- sented here, however, with especial reference to the comparative productiveness of first-generation crosses and their parent varieties. In a future bulletin the results in these tests attributable to the effects of acclimatization and adaptation will be combined with results of other work and treated with especial reference to these factors and their influence upon yield. TESTS IN MARYLAND. WORK OF 1909. CHOICE OF VARIETIES. In order to make the tests of as much practical value as possible, varieties grown by successful corn growers in Maryland and adjoining States were chosen. Composite samples shelled from a hundred or more ears were used in order to equalize results of individual ear variations. Detailed information regarding the history and description of these varieties is given in Table I, together with the germinating power of each lot of seed, both in the spring of 1909 and of 1910. 12305°—Bul. 218—12——2 —————————————— eee . “pees (8 [BULSLIO 0} Joja1 WoNeUTUIES Jo sede} MooIEd JOY} [[B ‘606T JO POIs 0} SAOJo1 OUO IOMOT OY} WUINIOD OTST OY} UT sodviq Jo sUBOUT Aq WMOYS WOT}CUTUIS Jo sodvyUdoIEd 0414 OL} JO B061) 66 { } 0°66 |S2°6 | 09:6 |-""3Uep Molex | OZE |°""SIBed eT Joy ‘ONO “BuTqUg [~~~ *-"- “Toate OBCIVIO JO WoTooJos ornd y |-***-* “""81 WOTOETOg 96 06 _| 0°S6 | OOO | OO'OT |°-~~” “py ODEteer GZI_ |°°""O88T outs ‘BA ‘AIOyOTH |-->> 7 “""-ureiys peiq-oind AyArey pues youNYSIP YW }--- 7 “**"Supy Al0x0TA oor 66 0°66 | cure ogg [oc etstops< "| azn. [ott “-op---{ ‘ZO6T 9OUTS porq ed \}.-... Se cach as ‘0 66 6 four M Ajunog euoog YM Suryy A1oyOL;T JO sso1g OCT "ON O01 : : | Rae ' “ZO6T "Z06T GOUJS \|........ Eee se Sey O0T 66 f| £86 | $66 | 00°6 FUSP OVUM. | OCT { aouls “Q *q ‘uoZuryseA, | porq end ‘oz AA AJUN0D ouOog YIM UOS}oq Jo aa O0T “ON 8S019 16 BO ai/0:085) 096" .|.08 8. e) MOP Pee | OCT: | Ses UST UGa| tal wae s “song Apoorg jo odAy opqerwa yVyMOTOG |~--- 7 ee ozB[_ Perw ‘00 { \ 0°96 | S26 | 096 | ~"3Uep OFA | OCT | ~~ “O88T GoUTS ‘opYO “WOJeHTA | ----- “O88T BoUIS porq eINd ‘ssolo W |--" 77 “LL UO}VOe[Ag A 66 OOL | 0°01) ¢2°6 OG eee ODE ss OZI |" "“Sxvod cy 1Oy “pW ‘poomaed |-"" "777777 SuTpooig rvpnoyjsed ou Jo uyesys [BOOT VY | * quod Molex Aves eS 66 86 ¢°€6 | SZ°8 =| 008 PERU D BOO AS | OR Gens 2 VLSTOOUISe OPO TS |" 5” a” ee es ae ae TL8T SOUIS UOLJOO[OS BIN |e 9[sBG] UAP[OL) ) OOT cs C98 | 93'6 =, $L'8 SP TCGDIOMU ANG LOLI | aa mes HOm Om OL NT AGIUisult ce mae ee et eee "068T SOUTS TOTJOSTOS GOAN, |" ----- = OULULIOATIS 00T oor | 0°86 | O¢'8 oo'2 = |°79UIB MOTAA | OOL | “UUOD ‘pjaysey | "* 777777“ WoRoeTes SIBOA [BIOAOS JO SSolo BIquysuN UW |---- >>" ““4uIT[W pUqAH sosinyg oO OOT 96 ¢°86 | 00°6 GL’8 oe ORF OU alae See COWS [[TOUAT ASG Galli: ie cg sheer LPS] POUIS poiq ond ‘ssolo Vy yued MOT[POX Prey vA OOT 6 ¢°18 | 06 (0,1) | aa aa) ea nd GIT |*savod GZ 105 “TIT ee St ee ae ee Ge “-“BUTLUvO'T OLYO WoIy UOTJOoJag |~--**- ~~~ sururve'y SIOUN][T a ’ 9G) = 66 66 6°66 | SZ'8 6Z°g = |-°-quep woe, | OTT | CouTs ‘oro ‘moySuruTLAA |--- Tee **""QZ8T BOUTS MOTOo[Es oInd W |---"** 7" 777777 SuUIWIvE'T OTYO S 66 16° ¢°96 | 00°6 C26 ---* ==> == TT 611 ON Rlecolutals) y=I : “OL6I | “6061 ee ior eee ON: AT OLTas. ° Sosa *Aqoul -eieues on “oIny eaomg | SM “SSB PUL JOJO; ar ane Cieraniay Mepre ‘sey uoIt “SoU A, = sk{vuq (quo *(700}) Jed) MoyeuTMey) | ¥[P4S Jo WYSsTOTY x N 10 *3]89) punjhanjyy Ur pasn sassola worjnsauab-js.1if pun ULOI fo saya, —'T ATAV], TESTS IN MARYLAND. ata CROSSING THE VARIETIES. Selection 119, which has been undergoing improvement for 10 years by the ear-to-row method of breeding and adaptation to con- ditions of the Potomac River soils near Washington, was chosen as the male parent, and the crossed seed was obtained by planting one of the other varieties in every third row in a field of this variety located 3 miles south of Washington, D. C., on a small tributary of the Potomac. As soon as the tassels appeared they were removed from all the varieties, so that no pollen matured in the field except on the rows of Selection 119, which fertilized the silks of all the other varieties, forming the supply of crossed seed, the productiveness of which was compared in 1910 with pure seed of the parents. About 30 of the best ears from these detasseled rows were chosen as seed for these tests. ‘These ears were shelled, making a composite sample of each cross, which was used in planting all of the tests. A supply of the original seed of all the varieties used in making these crosses was retained in the seed-corn room of the Department of Agriculture according to the best known methods of seed preservation. GROWING PURE-BRED SEED FOR COMPARISON. In order that the tests of productiveness might not be restricted to the old seed of the parent varieties, isolated plats of eight of the ‘ varieties, including the male parent—Selection 119—were grown in 1909 from the original seed. These 1909 plats were grown in the same localities and under the same conditions as the original seed. WORK OF 1910. LOCATION OF TESTS. Duplicate tests of productiveness were made at Derwood and at Pike Crossing, Md. Derwood is located about 16 miles northwest of Washington, where the soil is of a red-clay, flint-stone nature, and the two tests were located on similar soil. Pike Crossing is situated about 5 miles north of Washington, where the soil is of a mica, red-clay nature. At Pike Crossing the two tests adjoined, but the first test was located on land that had been in sod for some 10 years or more, while the duplicate test was located on impoverished soil that had grown truck crops for fully as many years. At these points the season of 1910 was unusually dry and unfavorable for corn. ORDER OF PLANTING THE TEST ROWS. In order to have the means of comparing the productiveness of the crossed seed grown in 1909 with seed of the parents grown the same season and with the original seed of the parents used in making the crosses, the plantings were made in the order shown in Table IL. 218 12 CROSSBREEDING CORN. It will be seen that by this order the original or 1908 seed of the two parent varieties is planted on either side of the crossed seed, and that adjoining these two rows is a row from the seed of each parent grown in 1909. In all four of the tests the varieties were planted in the same relative order. EQUALITY OF CONDITIONS FOR GROWTH AND PRODUCTIVENESS. Care was taken to so locate the rows that those to be compared would have equal facilities for growth and productiveness. At each location and for each test rows of uniform width were marked off both ways. Five kernels were planted in each hill and the stand thinned to two stalks to the hill. Practically a perfect stand of plants was obtained for each row of each test. Each variety and first-generation cross was thus represented by the same number of plants, occupying the same number of square feet of adjacent, appar- ently similar, soil. : PRESENTATION OF RESULTS IN MARYLAND. FIELD RECORDS IN DETAIL. Table II presents full details of both the original and the duplicate test at Derwood and of like tests at Pike Crossing. The order of occurrence of the varieties in the table is the same as in the test plats. TABLE II.—Tests of parent varieties and first-generation crosses of corn. At DERWOOD, MpD.1! First test. Duplicate test. Yield. Yield. an n c= r= ° 7. 7 I - 29 bese cee 5 .: | Number of $ S| Number of la Petal | z > 3s 5 & |es| 8 8 } 5 3 |¢ 8 8 S 2 mz |e lsh|o |a 1a) 24 8 |S) ) oe Lbs. | P. ct Lbs. Lbs. | P. ct. Lbs. 10 | Selection 119, 1909....| 100} 53 }-..-..-.- 35 45 52} 100 M0 |p 65 B 65 11 | Selection 159, 1909..... 100 54" Soe 40 51 47 98 66; 1h oe 60 26 60 12 | Selection 159, original.| 100 642225 45 59 51 100 i 1 see 60 30 61 13 | Selection 159 Selec- ites gd BE ee 100 56) — 3 20 71 61 | 102 71 1 60 41 60 14 | Selection 119, original.| 100 60) 522 a5 40 56 61 99 66 i-- 28 65 31 63 15 | Selection 119, 1909...-.. 100 63" |-es-= 50 45 59 100 JA Te ee24 63 34 61 16 | Selection 137, 1909..... 100 oe 35 56 67 98 60.)...-22¢ 55, 37 66 17 | Selection 137, original. 97 ot eeeee 40 43 62 100 3 ee 60 37 61 18 | Selection 137 XSelec- (iitas ath 6 Lt ee ee een 101 67 8 40 60 67 100 75 6 65 33 72 19 | Selection 119, original.| 100 DON ese see 45 43 62 98 G8: sceee 50 45 64 20 | Selection 119, 1909... - 99 6Y 2 <2255 35 57 59 100 70) |pxesee 65 29 60 21 | Selection 138, 1909....| 100 APA ore Bs 26 59 71 100 SL eee 45 42 74 22 | Selection 138, original.| 100 7 fl (ee 20 70 66 99 60 |-2 Lee 50 45 68 23 | Selection 138 x Selec- Wong see | enh a 58 | — 9 50 54 74 100 68 0 60 38 69 24 | Selection 119, original 100 Cs 30 62 61 99 bo |255-e3 45 41 59 25 | Selection 119, 1909....| 100 GF The 2 57 39 aff 100 oy Se 55 43 55 218 1 Length of row 164 feet. TESTS IN MARYLAND. 13 Tae II.—Test of parent varieties and first-generation crosses of corn—Continued. At DERWOoD, Mp.—Continued. 32 bases | Field row No. SHS & RES BES aR RB SBA B2S First test. Duplicate test. : Yield. 4 Yield. n n Variety and cross = be = I | % $ © 5 | Number of $ © | Number of | S o9 ears. = o§ ears. ms o a ol 2 5 2 BU, ac x | 3 el ay: s Ble leal B/S /E} a] ae leel el ele a | iS) S z S ad ) S a Sel |e es) Sea | ee |e a | SB A aed ome Selection 119 Selec- Lbs. | P.ct. Lbs Lbs. | P.ct Lbs (ine ee ee 100 60 | —10 60 64 51} 101 66 | — 50 45 62 Selection 119, original.| 99 5 oa | See 20 74 54] 100 (AU eens 2 60 34 63 Whitecap, original....| 100 4O0e 25/3 35 63 49 | 100 ao |eoeeee 40 54 58 Whitecap x Selection LIN |e oe Se aaa 100 58 | —13 30 70 55 | 100 72 6 60 39 ip: Selection 119, original.| 100 fa ee ot 54 60 53 99 S39 See 55 39 55 Selection 119, 1909....| 100 bONes sess 50 47 49} 100 WOiesce se 60 36 56 Ohio Leaming, orig- Tit) | Oe ae 100 eh ee 26 63 27 100 1 eS 50 33 31 Ohio Leaming xX Se- MBeHON 9 W325 =< 100 56 | — 8 35 70 35 100 74 17 7 30 41 Selection 119, original.| 100 DOE aes 32 65 53 97 i eee 50 47 50 Selection 119, 1909. . 98 56 | =.= 2 25 64 53 | 100 56 pees 65 39 43 ani Leaming, orig- 2 &-P ee eS saseee 100 AGN <-> 5 41 52 35 101 cL eer 50 38 34 nines Leaming X Se- leetion. A193... <0. 99 58} — 1 59 55 47 100 55) — 7 45 52 42 Selection 119, original.| 98 48 y= = 3). 35 63 52 | 100 54, |e-2ake 45 54 50 Selection 119, 1909... . 99 GI eesass 46 48 58 100 62 |eote22 60 39 48 Reid Yellow Dent, OMmpinale 2.4. 225. 99 50) Beccse 47 46 39 101 49) ||zaseee 56 29 29 Reid Yellow Dentx Selection 119........ 99 61 | — 6 45 56 50 99 60 3 60 43 49 Selection 119, original.| 99 5O er oes 45 49 61 99 56 | 4eeeR 3 50 52 af Selection 119, 1909....| 101 69) [ee 332 50 51 62 101 753} Bese 55 39 44 cas Hybrid Flint, TP iStih ats sae 100 34. lBe 5 ° g ears. = ° z ears. oa DS 3) 5 ae Biohgatl canto) ie 3 elegy. ai = 5 ny aa & > n La & > = 3/4 /3a| 8 3 | 32.) Shee = zg/sl##\S12/2/2|4|48#|8 1212 73 | Hickory King Selec- Lbs. | P.ct. Lbs. Lbs. | P.ct. Lbs. tion iG... eke. oe 101 63 7 52 50 79 | 100 74 21 77 24 83 74 | Selection 119, 1909....| 100 62) e.. 22< 30 74 59 99 ey eee 48 47 59 75 | Selection 78, 1909....- 100 Dee. 35 62 50 99 if Bee 54 41 51 76 | Selection 78, original..| 99 i I eee 35 77 48 99 90 Jota! 60 37 55 77 | Selection 78 x Selec- UL Crag Le a ee eee 99 58 | — 5 20 80 56 99 70 4 60 41 67 78 | Selection 119, 1909....| 100 (eh eee 38 64 60 99 70". 33s 50 47 65 AT PIKE CROSSING, MD.}! 3 | Selection 159, original - By mistake this row was cut. 73.1" 16) eee 5 46 35 4 | Selection 159 Selec- } | j lon, (IONE Sse bee 82 40 | —20 32 42 39 79 rid 0 0 46 34 5 | Selection 119, original.| 80 al eee 47 32 39 82): 10) [Se ae 0 39 35 6 | Selection 119, 1909....| 79 SOs 2 Se 51 24 40 82.5 UL" ese 0 50 37 7 | Selection 137, original.| 81 rb ee 32 36 40 79 Fit a pee 0 27 31 8 | Selection 137 Selec- rites ib eee ee ee 82 50 2 47 32 46 76 6 | —44 0 30 26 9 | Selection 119, original.| 78 Ad | Ses - So 40 34 45 86 TEA 38 0 39 31 10 | Selection 119, 1909....| 82 yi ee 48 30 42 82] 10% |S22222 1 51 32 11 | Selection 138, original.| 76 SG 29 38 48 80 4h |e ias 0 24 32 12 | Selection 138 xSelec- ; tron VISE. - oaccmee 85 55 16 54 27 61 82 5} | —49 0 25 43 13 | Selection 119, original.| 79 5A ae oe 36 35 48 80 72 es 0 33 | 33 14 | Selection 119, 1909....| 86 zk See 45 36 46 77 Vad} |Saee 0 48 34 15 | Selection 119 Selec- Ort L19ee. = Bee ke 80 44 | —12 43 31 42 76 7 | —45 0 33 35 16 | Selection 119, original.| 80 43) ss 39 37 43 79 82 |..228 1 38 36 17 | Whitecap, original....| 80 39 ee 40 26 42 7 4}. ee 0 21 29 18 | W piece X Selection iD ee See eee 84 48 | —4 43 33 49 81 5 | —61| °~ 0 26 39° 19 | Selection 119, original.| 85 zal (2 See 44 34 45 79 GEslensess 0 36 35 20 | Selection 119, 1909....| 83 Sill sees 47 32 50 82 144 [ees 1 51 37 21 | Ohio Leaming, orig- : toh aS {Ree ae ee 81 3671222 31 48 25 81 8) |eaee 1 43 21 22 Ohio Leaming Selec- tion, TOM 2. teens 83 45 | —16 48 29 34 80 9 | —36 0 46 27 23 | Selection 119, original.| 80 it A ee 48 28 48 81 | 12k |e 2 49 38 24 | Selection 119, 1909....| 81 54 eee, 50 29 50 80 {M132 -|s 2 0 54 37 25 | Illinois Leaming, orig- Tt Re eee RRS 78 AS eae 51 28 33 82 del | ess 0 41 30 26 | Illinois Leaming x Se- leetion! 1199-252, 2ee 83 47 | —12 52 22 50 82 8 | —44 0 43 39 27 | Selection 119, original.| 79 G0} |\ Seen 52 24 47 81 OF te 0 41 41 28 | Selection 119, 1909....| 81 GS | | ae 52 24 57 79)| 152 eaeee 0 59 35 29 | Reid Yellow Dent, Original .22. S225. 80 36 Roce 38 36 32 78 64 |------ 0 38 26 30 Reid’ Yellow Dent X Selection 119....... 82 49|—7 54 24 45 81 | 1223 | —27 0 59 36 31 | Selection 119, original.| 82 Gall: Sea ol 44 32 49 3 Va be 2 ee 0 48 41 32 | Selection 119, 1909....| 82 Cyt | eee 47 28 54 811200)... 0 65 39 33 cree Hybrid Flint, ginal?> J 2.secect<) 85 |e) | ee 44 33 27 81 7 |boooe 0 36 26 34 Ses Hybrid Flint Selection 119...... 82 49|—1 56 20 41 82} 19 | —15 10 50 37 35 | Selection 119, original.| 82 AQ ME 3 55 21 45 80!) 2h lbesces 2 54 46 36 | Selection 119, 1909....| 83 ATONE coe 36 39 49 T7.|) 24B emcee 4 57 41 37 | Silvermine, original...) 77 32) es ce 20 52 46 73 |r 14p eee 0 55 24 38 | Silvermine Selection NNO Nn os Ae aioe 86 40 | —20 33 37 39 82} 144 | —12 0 58 37 39 | Selection 119, original.| 79 BONeas ce 44 32 48 79 Tlecetee 0 32 46 40 | Selection 119, 1909....1 82 BS) las ae 48 31 52 81 BF bee. 2 0 40 42 1 Length of row 135 feet. 218 TESTS IN MARYLAND. 15 TasiE II.—Tests of parent varieties and first-generation crosses of corn—Continued. At PIKE CrosstnGc, Mp.—Continued. First test. Duplicate test. Yield. Yield. geye & : Variety and cross. 3 by ‘ 3 be S - DB = = Number of a Ss | Number of = og ears. og ears. > ° a ° me o we os w os s a oh Bu | 2 ea ae i Lo} . o = : 5 . Z eeege ee | Sie 6 | ate Bal Soe ae & Sy (PES Ciara ellen ele hea A eA |e Nopeis Nees Lbs. | P.ct.| | Lbs. Lbs. | P.ct Lbs 41 | Golden Eagle, original.) 74 264 =e) 20 46 25 81 Wh ide ae 0 20 21 42 | Golden Eagle x Selec- | ROT LILO! oe srorefaiere oo 78 45|/—8 26 46 36 84 63 | —21 0 39 32 43 | Selection 119, original. 74 45" | 25 ee 40 28 45 80 Te | Soa 0 34 43 44 | Selection 119, 1909... . 78 Abt ets. 44 28 46 80 co) ee 0 39 46 45 | Fraley Yellow Dent, oniginall = 2.22... 79 HOw esti 48 27 53 82 5-2 |be ase 0 29 46 46 | Fraley Yellow Dent X Selection 119.......- 77 44 |} —10 40 25 53 84 94 12 1 44 54 7 | Selection 119, original. 79 SOM Ee eee 47 28 55} 181 Sk |Pcaee- 0 44 49 48 | Selection 119, 1909... - 77 Sails oe 48 23 58 81 a | Sete 0 58 51 49 | Selection 77, original. - 77 oe ae 40 32 50 82 3 2) a ee 0 40 42 50 | Selection 77 X Selee- yr) 0 de [ht ee eee es 71 46 | —13 41 21 48 82 8 —20 0 44 48 51 | Selection 119, original. 78 D2ia| meek <2 40 34 56} 181 te lees ar 0 42 52 52 | Selection 119, 1909... . 79 DS) |eeses= 44 29 59 82 Shilscsee 3 0 42 49 53 | Red Blaze, original...} 79 44 lez tsee 52 20 44 81 Giyalesesez 0 37 29 54 | Red Blaze Selection MO te ES boss 73 48|-—9 52 18 45 81 7 —20 0 42 44 55 | Selection 119, original. 78 SD ileisem ice 48 24 54 |. 182 1S Bsecee 1 50 48 56 | Selection 119, 1909....| 73 52/5 82 52 16 58 82 |PyI2k iz dsaee 1 51 48 57 | Cross 100, orizinal..... 80 Ts ee ae 40 24 49 82 gS el eae 2 16 44 58 | Cross 100 X Selection Li SSS oe eee aes 71 48 | —14 48 17 50 81 10 —31 4 35 55 59 | Selection 119, original. 72 S26) a. 222 52 17 50 | 182 IGE, | Sees 4 45 50 60 | Selection 119, 1909.... 82 (0 ee ee 52 24 51 82 TSO IE Seer 5 45 57 61 | Cross 120, original..... 65 ABieece 2: 38 24 48 81 Lidalest: 10 36 44 62 | Cross 120 X Selection AOS) # bess eeates 77 58 12 60 12 57 82] 203 22 10 42 56 63 | Selection 119, original.| 82 Chl naa ee 45 38 AT Mek So: |e de || roses 6 46 53 64 | Selection 119, 1909....} 80 ZT eee 36 37 51 SO) ere |p 6 39 53 65 | Hickory King, orig- ale... hee ese. 85) ease 44 20 56 80 IS* |p seeee 12 45 47 66 | Hickory King XSe- lection 119.......... 75 49 10 58 14 51 83 173 6 6 40 54 67 | Selection 119, original.| 75 AD ee as 28 3G Dae 804| 1645) see 3 49 50 68 | Selection 119, 1909... . 80 ABA = Seat 36 40 48 80 ISH Wee 5 5 33 48 69 | Selection 78, original... 77 So eerce <= 24 39 33 83 Oe eer 0 34 36 70 | Selection 78 X Selec- MOM AIG. 22522 se -5c.- 2 82 42 2 32 38 36 81 144 11 4 41 42 71 | Selection 119, original.| 80 Si laste: 20 46 AG NARS ile oat Ss |e 1 41 45 72 | Selection 119, 1909....| 81 Siulbeee oe 23 43 46 Zieh walsy we an eee 6 39 41 1 1909 seed substituted for original seed. Table IT shows the usual inexplicable variations of test-plat work. Especially do such variations occur in the duplicate planting at Pike Crossing where the soil was so deplete of humus that from a financial standpoint the crop was a failure. Under these very adverse con- ditions it is rather surprising that the results accord with those of the other three tests as well as they do. COMPARATIVE PRODUCTIVENESS OF SEEDS OF 1908 AND 1909. Table II shows 42 instances in which the 1908 seed and 1909 seed of the male parent were planted in adjacent rows. In 33 of these 42 instances the 1909 seed produced the better, in five the 1908 218 16 CROSSBREEDING CORN. seed produced the better, and in four the yield was the same. The 1908 seed produced 1,797 pounds of ears and the 1909 seed produced 1,938 pounds, a decreased yield of 7 per cent, due, perhaps, to the poor development or loss of vigor of the 1908 seed. The 1909 seed was grown from the 1908 seed under conditions that prevented any crossing with other varieties. Its greater productiveness therefore can not be attributed to mixture with other varieties. While the 1908 seed of Selection 119 produced 7 per cent less than its progeny seed grown in 1909, it is not certain that the age of the 1908 seed was the cause of the decreased productiveness as the seed germinated perfectly the spring following its maturity, and also showed a germination of 98 per cent in the spring of 1910. The 1909 seed showed a germination of 100 per cent in the spring of 1910. A comparison of the productiveness of the 1908 and 1909 seed of the female parents shows sufficient instances in which the 1908 seed produced better than the 1909 seed to make the average production of the 1908 seed equal to that of the 1909 seed. CROSSES COMPARED IN PRODUCTIVENESS WITH THE MALE PARENT. In computing the per cent of increased yield over the male parent in Table IT the seed of the male parent grown the same year the cross- ing was accomplished is considered. As none of the female parents consistently produced better than the male parent, the male parent of all the crosses, Selection 119, is taken as the basis with which to compare the crosses. In all cases the average yield of two rows, the nearest one on either side of the cross, is compared with the cross. Considering that contradictory results from any of the four tests is sufficient cause for ignoring all four of the tests, we have remain- ing five crosses which produced uniformly less than their male parent, and two comparisons in which the cross uniformly produced better than either parent. The five first-generation crosses (X Selection 119) that uniformly produced less than the better of the two parents are Illinois Lea- ming, Sturges Hybrid Flint, Silvermine, Golden Eagle, and Selec- tion 77. The two first-generation crosses (X Selection 119) that uniformly produced better than either parent are Cross 120 and Hickory King. COMBINED RESULTS OF THE FOUR MARYLAND TESTS. In Table III the four separate Maryland tests are combined. In the Derwood test some of the female-parent varieties were represented by both 1908 and 1909 seed. In such instances the average of the two has been used. In these combined results this comparison of the crosses with the better yielding of the two parents is a straight comparison of the crosses with their male parent, for it 1s more pro- 218 TESTS IN MARYLAND. Bi ductive than any of the female parents except Fraley Yellow Dent, which it equals. TaBLeE I1I.—Productiveness of first-generation crosses of corn compared with that of the better parent, 1909 seed of the male parent being considered. Row No. Variety and cross. Num- ber of stalks.! Water-free basis, Ears. Tn- crease Ee ooo oj pf = Selection 159 X Selection 119. Selection 119, 1909........... RelecinOnl sie oo ons as cals Selection 137 X Selection 119. Selection 119, 1909........... POWCHOMN ISSR... ceess ese Selection 138 x Selection 119. Selection 119, 1909........... Selection 119 X Selection 119. Whitecap, original.........- | Whitecap x Selection 119.... Selection 119, 1909..........- Ohio Leaming, original...-.. Ohio Leaming X Selection Illinois Leaming, original. .-. Illinois Leaming X Selection LH oa tee on ee ee Selection 119, 1909.......--..- Reid Yellow Dent, original... Reid Yellow Dent X Selec- OMG) = Po emncio sees Selection 119, 1909........... Sturges Hybrid Flint, origi- feenon LIQ Ss ess. soce eae Selection 119, 1909........... Silvermine, original.......-. Silvermine X Selection 119 .- Selection 119, 1909........... Golden Eagle, original....... Golden Eagle X Selection 119. Selection 119, 1909........... Fraley Yellow Dent, original. Fraley Yellow Dent x Selec- {ACGEE 1 ma Selection 119, 1909..........- BAIGCLIOM Wipe eiaeloore es ose. osa3 Selection 77 x Selection 119.. Selection 119, 1909. .........- Red Blaze, original.......... Red Blaze X Selection 119.--| Selection 119, 1909..........- RTOSSILOU ae cba ass = oe oe Cross 100 X Selection 119 ....| Selection 119, 1909........--. CROSS OO Masa ee eS ia Selection 119, 1909........... BCIGMOLU I Sic oi=) aia: o.27ajo 5 :a0:5'= Ae: Selection 78 X Selection 119-.. Selection 119, 1909........... 359 348 359 359 359 361 360 Grain yield. Stover yield. Mois- ture in In- | shelled lft crease | grain crease Roce when ae s Wai eavier| ears Ears. so Weight. stover- were | produc- weighed. parent. ing parent Pounds.| P.ct. |Pownds.| P. ct. ‘Pxcts 178 | -—9 194 | — 2 31.4 L95? |Paee aces WGTASSeccee 4 28.8 37/8 Peers > O]0e ee ae ae 28.5 198 3 211 6 30.0 190/152 2 hae LOH oe Fee 28.8 TAS Soo 22222 221!) Beene se 30. 2 187 | — 2 247 12 31.9 TGP ee 0 eee 28.8 177 | —10 190 | — 1 28.8 aS oeeaeee ial eee aoe 27.2 183 | —7 215 12 27.7 DOR Woo s os 0 ny legen ee 2 28.8 PAD) eee a a aa ae 22.1 184] — 4 137 | —27 22. 2 LSOM| Soe eenes TSS ese ce ces 28.8 ADEE Sects 132 Soseocns 27.6 168 | —9 178 | —7 26.7 LOL |eeosseme TOS o.cs cose 28.8 1 F976 VE ea a cA ig) |e eae 24.8 183 | — 5 180 | — 9 26.3 1d oer LOOM e eeeee 28.8 1030 weetaoee DDN eer sys 19.9 170|—9 162 | —18 25:5 A78t | hoses JO5h|Haerenae 28.8 138) |Poscecse 7 V8 lg (eae Paes 23.8 166 | —11L 167 | —18 27.6 IGT a ecaare ste 1} WY. bn) as 28.8 (5 i aes 1 i a 25.6 169 | — 9 157 | —25 25.5 Mi5g| st cee OB sage 28.8 LY 6 eee aes 7 (il ele 27.2 173 | — 3 231 6 29.2 S80) |e22252 PAVE eee west 28.8 LG S| e7 eee eis NOD ee anecen 30. 7 167|—9 197 | —9 30.0 ISG) Sos. PPR il EAS 28.8 LAT | ey eh AnH Eee Ses 26.0 180 | — 5 184 | —16 27.4 193 Eh eal MATES Ste L8 28.8 138) |iz-e ee cee if) al (Pea 27.4 169 | —1L 208 | — 0.2 29.3 ibs Aedage 203) |acetera cies 28.8 iO) | 2eee. = TSSHeH2.. S50 32.2 215 20 234 14 29. 2 PAE. 741 eee al 28.8 T64e. aniecisa 265" ean ae. 33. 7 204 13 267 1 32.0 ASG: PRIS os Den tseek. tos 28.8 163) |i 5-5. ily hal ese 28. 1 184 0.3 201| — 6 29.8 113 Beets Pt ea 28.8 1 Length of row 598 feet. 12305°—Bul. 218—12——3 wee eweee weet eeee 18 CROSSBREEDING CORN. Eleven of the fourteen crosses of distinct varieties produced less grain than the better yielding of the two parents. When the pounds of ears harvested is reduced to a water-free basis, according to the percentage of water in the shelled grain at harvest time, the general results remain the same, namely, 11 comparisons in which the first- generation cross produced less and 3 in which it produced more than the better yielding of the two parents. In Table IV those crosses which produced better than either parent are classed as advantageous. The others are classed as disadvan- tageous. TaBLE 1V.—First-generation crosses of corn (male parent, Selection 119), showing pounds of grain produced (water-free basis) and classified as advantageous and disadvantageous. Yield. Female parent and classification. Of parent. Tncrease = Of cross. Hottcr Female. | Male. parent. Disadvantageous—Crosses less productive than the better parent: | Pounds. | Pounds. | Pounds. | Per cent Whiteca 106 132 e aD eee ee eee 141 — 6 NNGIS ERMINE eno a ass ace acne Se ee toet oe seer 103 132 123 —7 Raid Vallow Dent. 220 ~t dco secs = He ase sere ares eee 107 138 135 —2 Sturvesety brid) Whtt.co2 ce. o soeens oo eee see ne senna 83 133 127 —5 Bilvermuiney conc -hes—c ce ts nes espe cae eine em a = ar oe eel 105 134 120 —10 Goldan Wail st eceseee a oe aes tan cere eas emer eeeseeas 87 132 126 —5 Fraley Yellow Dent.....-..-.-- ee nr eRe eee 126 126 122 — 3 SGIGCHONY = ctee cece sess see sc cpsaocee asa awee duleneine epee 116 130 117 —10 HLGOGMALOs. coos e pecs sere pee oc ao aes canes Repeat 109 135 131 —3 ho UU US i seals AE mos acl 2 Ak Whe RE AE, erly Peele mae 100 135 120 -—l1 SeleCtlon WS~ s.cjicimcin coe sce =e eae Soe eee ea tee eee ee 117 131 129 -—1 ASVOTAGG wie se 5 oe aos cn se oe ee agate hala iors 105 133 126 — 6 Advantageous—Crosses more productive than the better parent: OMOPLSRITING «See oe eee sae ae nen gaan 109 137 143 5 Crpeshl DUS 23a. 2 eee eee - cen ere oe ae eee eae mee ae oe 121 128 152 19 ICKL RN See eee one ae eee ee ee lanier 109 128 139 8 IVOTAUC a anc 3 5 riae See wee epee oon ose oto meaiain aes 113 131 145 10 ADVANTAGEOUS CROSSES. Without consideration of water content the Ohio Leaming cross would be a disadvantageous cross, but the dryness of the ears, due doubtless in some degree to the earliness of the female parent, causes it to fall into the class of advantageous crosses with an increased yield of 5 per cent over Selection 119. A cross made in 1900 in which this strain of Leaming was used as male parent also produced dry and unusually solid ears. Cross 120 was originated in 1902 by planting occasional rows of Hickory King in a field of Selection 119. All Hickory King stalks were detasseled. Since 1902 Cross 120 and Selection 119 have been improved in yield and adapted to climatic and soil conditions near Washington, D. C., by yearly growing ear-to-row breeding plats and saving seed from the best stalks of the highest yielding rows. 218 OO TESTS IN MARYLAND. 19 It is of especial interest that these two improved, acclimated, and related strains when crossed in 1909 should give a first-generation cross of much greater yielding power than either parent. This first-generation cross produced better than any of the other first- generation crosses and better than any of the other varieties tested. It is the only cross that produced far better than either parent in all four tests. By these tests the value of the seed of this particular first-generation cross for the conditions prevailing at these points in Maryland in 1910 has been demonstrated. These two strains are now being crossed extensively in producing seed for general planting. This cross-pollinated seed is designated “‘ First-Generation Cross No. 182.” The third and last advantageous cross of the 14 crosses, as classi- fied in Table IV, is the same cross that gave origin to Cross 120, which, after six years of selection and adaptation, produces some- what less than the first-generation cross of the same parents made in 1909, after each parent has undergone six years of selection and adaptation. This fact indicates that it is more profitable to accli- mate and improve the parents of an advantageous cross separately and cross them yearly to obtain seed than to cross them once and then rely upon the acclimatization and improvement of the cross. Furthermore, since Cross 120, after six years of improvement, when crossed with Selection 119 gives a first-generation cross of superior productiveness, it would seem that the recrossing of a cross some- times gives better seed than the crossing of the original pure-bred varieties. The advantage may be due to adaptation, as one of the original parents, Hickory King, has not been adapted to conditions near Washington, D. C. DISADVANTAGEOUS CROSSES. The Whitecap variety is adapted to conditions in Delaware, where it is quite extensively grown. It yields a very large ear, with a large cob, and yellow kernels with white caps. Neither in weight of ears as harvested nor on a water-free basis did the first generation cross of Whitecap and Selection 119 produce as well as the male parent. The Illinois Leaming, though a pure selection from the Ohio Leaming, is now very unlike it in appearance. The Illinois Leaming is of a rougher type, with broader kernels. According to pounds of ears at harvest the crosses of the two strains of Leaming with Selection 119 fell below the male parent in production. The Illinois Leaming cross did not produce as well as the Ohio Leaming cross, and the grain contained more water at harvest time. Making the comparison of yields on a water-free basis the Ohio Leaming cross is advantageous and the Illinois Leaming cross is disadvantageous, 218 20 CROSSBREEDING CORN. Sturges Hybrid Flint, the only flint variety used in these experi- ments, is a large-eared yellow corn adapted to Connecticut condi- tions. It has stalks considerably shorter than those of the male parent and is 20 days earlier. ‘The cross was intermediate between the two parents in size and time of maturity. The first-generation cross produced much better than the female parent, but not quite as well as the male parent. Silvermine, a white dent, and Golden Eagle, a yellow dent, are the earliest varieties used in these experiments except Sturges Hybrid Flint. Their first-generation crosses with Selection 119 produced much better than the female parents, but not quite as well as the male parent. In comparison with the results from this same seed as tested in California (discussed later) it should be noted here that, while in Maryland Silvermine is but an average producer and Golden Eagle is second to the poorest of all the varieties, under California conditions both these varieties rank very high in production. Fraley Yellow Dent is the variety that for 15 years has been grown on the Derwood farm on which two of these four tests were made. It is a productive variety adapted to the conditions at Derwood and unrelated to Selection 119. Among the 14 first- generation crosses tested this is the only instance in which both parents are more productive than the first-generation cross. The 1908 seed of the female parent produced slightly better than the cross. Except that Fraley Yellow Dent differs in color from the male parent and has not been improved by ear-to-row selection, the conditions of this disadvantageous cross are similar to those of the most advantageous cross of the series, both parents being well adapted to climatic and soil conditions and highly productive. Selection 77 resembles Cross 120 and like it has undergone many years of selection. Cross 120 is adapted to Maryland conditions, and Selection 77 to Scioto River Valley conditions in Ohio. With Selection 119 as male parent Cross 120 makes a highly advantageous cross and Selection 77 a disadvantageous cross. Cross 100 was made at the same time (1902) and in the same manner as Cross 120, Boone County White being the male parent in each case. Hickory King, a broad-kerneled small-cobbed corn, was female parent of Cross 120, and Dotson, a long-kerneled, small- eared, small-cobbed corn, was female parent of Cross 100. The two crosses have had similar ear-to-row selection since 1902. Cross 100 has yearly been grown on poorer soil than has Cross 120. Although of such similar history and treatment, when these crosses are crossed with the related variety, Boone County’ White, one 218 TESTS IN MARYLAND. re | makes a highly advantageous first-generation cross and the other a disadvantageous first-generation cross. Of all the varieties used as female parents, the most productive and the seven least productive formed disadvantageous first-genera- tion crosses with Selection 119. COMPARISON OF FIRST-GENERATION CROSSES WITH THE 1908 SEED OF BOTH PARENTS. Although placing the odds in favor of the crosses, a comparison is here made between the productiveness of first-generation crosses and that of the parents as grown from the original (1908) seed. There are 31 instances in which the first-generation cross occu- pied a row between rows of either parent in which the 2-year-old seed was planted. In these 31 comparisons the cross exceeds the better of the two parents in 14, equals it in 1, and produces less in 16. Of these 16 cases the male parent exceeds the cross in 15 and the female parent (the Fraley Yellow Dent variety) once. It should be noted here that if these Maryland tests had been restricted to the original seed of the parents, as has been done in a few reported tests of this nature, the first-generation crosses would have stood much higher in production in comparison with the parent varieties. RELATIVE GRAIN PRODUCTION OF PARENT VARIETIES AND FIRST-GENERATION CROSSES. Expressed in terms of bushels per acre, allowing 70 pounds of ears containing 15 per cent of moisture to the bushel, the parents and crosses pale as follows for the four tests comipitede Di eumnCHELIOS SeRdS. te at uctro. semiat ty. Horas hese ovis aes cult aahwodedneseitans 49 First-generation crosses, 1909 seed...... UIA SRS 3 to EET we Se 47 15S UE SLD eo, 216 eee ol ad gy eee ats. a eae age gt a aN RSP 45 Poniaeaate its. Mostly, LOUS SECU. «1.00 hosvendsss sob cigs Sage ns Beea beeen ees 39 This relative production is shown in figure 1. As the yield for each field row shown in the diagram is the combined yield of a row from each of the four tests, the curves show the relative production of the different lots of seed with fluctuating variations and varia- tions due to soil conditions somewhat reduced. The four Maryland tests show the production of the crosses in general to be much above the average for the parents and somewhat below the male parent. Of the 14 crosses between distinct strains the cross of Cross 120 with Selection 119 is the only one that is remarkably superior to Selection 119 for the soil and climatic con- ditions under which the tests were conducted. The increased 218 29 CROSSBREEDING CORN. productiveness of this cross seems sufficient to warrant the crossing of these two strains in producing seed for general use in Maryland and Virginia, where conditions similar to those of the tests exist. As 1909 seed of the male parent occupied every third or fourth row in all four of the tests, a check or standard is afforded for com- paring the productiveness of all the varieties and crosses. In Table V the varieties and first-generation crosses are classified and arranged in separate columns in the order of their productiveness, the most productive being mentioned first and ranked as 1. In computing the comparative productiveness of the varieties and crosses for this table the yield of a variety is decreased or increased proportionately FIELD POW NUMBERS . / 5 fo 45 20 25 30 oS 40 45 50 5S : ULEAD TCA AAT UIT Tes Bi g 8 QBUSHELS PER ACRE 15 PER CENT MOISTURE, 82° &0 Fig. 1.—Diagram showing the relative production of parent varieties of corn and their first-generation crosses in Maryland, 1910: A, Male parent, variation of 1909 seed; B, male parent, mean of 1909 seed; C, mean of crosses; D, variation of crosses; HE, male parent, variation of 1908 seed; #, male parent, mean of 1908 seed; G, variation of female parents; H, mean of female parents. as the average yield of the two nearest rows of Selection 119 exceeds or falls short of the general average of Selection 119 for all rows in all the tests. From the seven best female parents the crosses of six are found among the seven best crosses, Selection 77 being the only high- producing variety whose cross is a poor producer. Along with this indication that the productiveness of the parents influences the productiveness of the cross there are sufficient exceptions to indi- cate that the productiveness of a first-generation cross is sometimes determined to a great degree by other factors. 218 TESTS IN MARYLAND. 23 TasLe V.—Parent varieties and crosses classified and ranked according to the computed production of ear corn (basis of 15 per cent moisture). . : . : Yield Rank. | First-generation cross (X Selection 119). Parent variety. per acre Bushels PRMOLONS 120s mate anes oe oe sete oe ack le rae cannons ote wells ce ecece ccgetecomaessaba sees 2) TESTA eel AG Yee 08 TRE ec os Se ge ads ics cnt 6 ta ICO SU EIOE BORE CIO DOO ne ance aasaaerac 53 PRI SCANT pe 2 re ee ee ee ce tet te ae meme nla cae sae sae cle sine acleinc sistee emote 51 | SS eS ee a ae er ae ae Selection 119 verene for 60 rows). - aes 49 Be eee aanciee Sees tec oaccicks eons =e pay Yellow Dent. 48 6 | Selection 78.......-. Wes 48 7 | Reid Yellow Dent... 47 8 | Fraley Yellow Dent. . = 47 DRIBINEM BIAZO ES ois. 254 ocn eheciece ice eke 47 SCPE eS EL U DIIGMliN tas teeta = Seca | = sent totes See ee ora eae ef Sejse Se wccecwecseess 46 HCG OCT APT Cnn. ose o te od cese ois |e nn onetime Somes cme oes ao eee Se ccedeeee eter 46 POM ee oe Soames cia ssc bc cate tce se escle ses Cross 120....-. eae Sgt Baers neo ese 46 SEMIN IIECCEM eae tts Key. cok ee. SRR EEE SYS BO OAS ee ARS tae es. ee eS Bt 46 PELE HIOIS CATT B58 stapes oc tis acts ereicim [s wrele Sie roye ats Winn Or iaicne oe cio nin winiwiniqarciniaie lula me eicimle 45 PE SIEMOGIING Lae No ae $5526. IS ej de ae al nade ceske ae Tae ae seeded = Sass gad tote bok 44 i = Bas Sa) OR SR aa eel he be edt madame orgie hrc cant ee 44 Selection Wate ase aa eee ee eee ee 44 BeleChONaieccce cre or noe noes eee eo 43 Ree ae ges SUS oe ako oa endl ea ke om Smee nee we ose sna Meee see at oe ees 43 HIckOny, Kanteen toa nano ean aoe ae ae 41 ed Blaze erase a. cease ee eee eee ee ees 39 Ohio Leaming....-.. ee 39 22<|pSilvermime . 2222). 2: 38 .--| Illinois Leaming... 38 ‘| Reid Yellow Dent.. 38 Wibiteeap Nes see os ac. See ieee kensce gaaeies 36 Cross lOO eon cme ood cata ce ae So acratewiate 36 Golden Mscler oa ees aaneeee an eneee see 32 Sturges He brid MING Fs Sees CTE ee 30 STOVER WEIGHTS OF PARENTS AND CROSSES COMPARED. As no determinations were made of the water content of the stover, a comparison of weights of stover at harvest time does not repre- sent food value and is of little importance except in indicating the earliness of maturity of the crosses and parent varieties. The stalks of the later maturing varieties contained considerable sap when weighed the latter part of October, while those of the earlier matur- ing varieties contained very little sap. In 4 cases out of the 14 the stover weight of the crosses is lighter than the average of the two parents. In 3 of these 4 cases the female parent matures fully 10 days earlier than Selection 119. In general, the crosses seemed intermediate between the parents regarding height and time of maturing. It seems that the earlier maturing parents transmitted to their crosses their early-maturing character in sufficient degree to cause the stover to weigh less than the average for the two parents. Sturges Hybrid, the only flint variety in the test, is an exception in this respect. In no instance was the stover weight of a cross as light as that of the lighter pro- ducing parent. The cross of Cross 120, which gave so remarkable an increase in grain production, also gave 14 per cent increased stover weight over 218 24 CROSSBREEDING CORN. the heavier producing parent and 16 per cent increase over the average of its two parents. The Whitecap cross also gave 16 per cent increase over the average of its two parents and 12 per cent over the heavier producing parent, but in grain production it fell 6 per cent below the better of its two parents. Of the 14 first-generation crosses of distinct varieties 10 produced fewer pounds of stover than the heavier yielding of the two parents. CORN CROSSES AT CHICO, CAL., 1910. CONDITIONS OF THE TEST. The crosses made in 1909 in Maryland were also grown at Chico, Cal., in 1910, in comparison with their parent varieties. The plant- ings were so arranged that each row of the cross came between rows of its parent varieties. The soil upon which these plantings were made was medium loam which had grown alfalfa for four years previous to 1910. The land was broken to a depth of about 10 inches in December, 1909, with a second breaking in April, 1910, to a depth of 6 inches, and marked out in shallow furrows 34 feet apart. Both plowings were made in lands running north and south and the corn rows were marked out east and west, so that no rows would fall on dead or back furrows. On April 14 three kernels were dropped by hand in each hill in the furrows and lightly covered with the foot. Hills were 34 feet apart in the row and 80 to each row. Four cultivations were given during the season. On account of the surface soil being somewhat dry at planting time and some seed being taken by gophers, an uneven stand resulted. The rainfall after planting amounted to less than one-half inch and no irrigation was given. Sufficient water was contained in the soil early in the season to give all varieties a good growth of stalk, the average height being about 84 feet. This moisture supply was not great enough, however, to produce a good crop of ears. Many of the ears were small and about 25 per cent of the stalks were barren. The number of stalks per row, number of hills, average number of stalks per hill, pounds of ears per row, average number of pounds per stalk, percentage increase in yield per stalk of cross over the better parent, number of good and poor ears, and weight of stover are given in Table VI. 218 CORN CROSSES AT CHICO, CAL., 1910. 25 The order of plantings is preserved in the table, but for greater ease in comparing the cross with its parent varieties each row of Selection 119 is given twice. The yield per stalk of the different varieties is represented graphic- ally in diagram 1. Dracram 1.—Variation in yield per stalk of crosses and parent varieties of corn at Chico, Cal., 1910.1 Field Pound. Variety and cross. Zo | 0.0 ba oa bs ou PeleChOH: VEGI fs 8. Sao oe ole oases oecie Tilinois LeamingX119 ............-..-- 24 Minoisseaminy’ 22.7.2) .-3:0 225-90. = 5t SelECHON (Se At ach t-Ree ons abies «teen 2 147 63] 2.3] 39 B51 57 68 | 117 . 796 17 | Selection 138X119: ...>----.---.-- 141 67} 2.1] 50 355 4 62 72) 156 1.105 18 \| Selection 138). 2. - ..-..-22sses-c23 146 69 | 2.1} 50 342) | pence 68 70 | 135 - 925 19)| Hickory Wing. 22. .---=---2--=2 122 59] 2.1). 27 727 Ne eae oe 56 62 | 106 . 870 20 | Hickory KingX119..........-.- 129 60 | 2.1] 39 303 | —15 72 52 | 122 - 946 91) ‘Selection 119....-.:.--.-.-------- 163 70| 2.3] 58 356) 2... 74 80 | 132 810 21 Selection: 119.2 2-eve. 3s. 5055-54 163 70| 2.3) 58 5 eee 74 80 | 132 - 810 22 | Golden EagleX119............-- 144 66 | 2.2] 64 445 16 92 47 | 120 - 834 Golden Eagles: 22-22222s2225222 122 58 | 2.1] 47 S85] 228s 72 42 75 615 28 WATEOCAD 6 o.0 oe see ac ae 109 50| 2.2} 26 238, | ..--24 35 52 | 110 1.010 25 WihitecapXau@:- sao can cseee 116 59 | 2.0} 37 319 8 44 56 | 129 1.113 26)) (Selection 119-22... -22-.-..--5..- 126 53] 2.4] 37 294 oot 37 69 | 110 . 872 261 Selection 119. ....-. 22:22:52.0 126 BSN Qa Sz tM ee 37 69 | 110 . 872 27) Cross 100X119 - csc es ete 123 61} 2.0} 40 . 325 11 55 60 | 113 -918 28) | Cross 100 oo cscs sees suse 121 58 | 2.1] 21 ry Bn ee 52 63 | 101 . 834 20)| Selection 150... 2---:.-2----<-2-% 99 Go) 159) 26 -263'\..- 28 34 85 859 30 ! ‘Selection 159X119_..-.....-..-.- 107 54] 2.0! 31 - 290 | —11 40 57 | 104 . 972 31] ‘SelectionW19; ve cc-~ oo. eee 115 52| 2.2] 374 326122 ee 46 57] 111 - 965 31.1 Selection 11922. oosceensceecencs 115 52] 2.2} 373 B20 Jee 46 57} 111 + 965 32 | Ohio LeamingX119............. 114 53} 2.1] 37 324 | —15 50 62 92 . 806 33 | Ohio Leaming...........c222.6- 102 54] 1.9] 39 SB2 ioe oe 64 40 60 - 587 34 | Sturges Hybrid Flint... -...-.. 79 49| 1.6] 19 PAL oo s285 40 40 67 - 849 35 | Sturges Hybrid Flint 119...... 106 50} 2.1] 35 . 330 | —11 52 60} 106 1.000 36) Selection 110. 2 3-- <> sna- 80 41} 2.0] 294 S36 (sez >4 42 40 77 - 961 36: | Selection 119.5. < Chisholm... 9-2 <---.550 sac 100 19 12 . 120 —2Z1 3 49 HO PPMUNSON Spots u sec tiic se eetsidcaweccactas. 97 21 9 2003) bere eed 0 43 Pie Chisholm sh e252: Shee. epee Ae. 79 1 13 Say ae 6 45 12 | Gourd Seed X Chisholm.............. 96 13 17 Si leiee 16 5 68 oieamera seca: 2-2) Re. 2 5 Peon A. $8 4 14 LAS 9S. 2 208 0 57 WAM CAMS OME Se te hehe oc a Geshe 89 0 123 LAOH See 6 39 15 | Lily of the Valley X Chisholm........ 100 7 184 - 182 5 6 57 16) |My; of the: Valley: 5.2... --2082.2..4.. 95 6 164 LAR es ee aes 8 56 iis MeSH Olina s =) oe Se. ee kB 78 2 124 Sl GON 225 5 Shee 4 43 PSiwelews >< Chisholm 2222-2 2.208.2.0 8. 101 27 144 - 144 —17 2 61 PORMAOW Reet op eee cee. 101 il 9 089 s}222 5 su 0 49 PORmOnASHOlM =. 525.5) Dee 3A A. 84 3 154 eLSA E22 ee 2 57 21 | Selection 136 X Chisholm.........-... 100 9 194 -195 23 6 66 ZAR SIeCoION L3G -. 2+ Saacc22 82-08-2225 FRic 101 13 16 S15 8"| Sone 3 72 Sti) (C) iv Gls) bat ee, ee ee ee Ce 81 8 104 ~ 130) Beer 0 48 24 | Surcropper X Chisholm............... 106 3 234 219 — 8 5 79 PAE || 1S) EEG 0) 6) 1X a a 100 6 23% 8 fd ees eae A 8 80 AGT MMESH OMI oes Pace tc kee hec.oh Sb. 94 8 12 ~28) || Seas © 1 47 27 | Dan Patch X Chisholm............... 93 8 23 . 247 13 3 83 2} (pene atcht ss. --2 $28.0255.-08....5 82. 94 5 204 SALSA 5 74 JD) || Ge Sl Tes 2 eee eee ee 89 7 12 Sibi Perea 4 45 30 | Selection 137 x Chisholm............. 102 22 174 «5-28-85. .1ohaess 20 53 0 20 27 11 | McCullough x Chisholm. ............-- 49 0 30 20 12:) MeCutlongh. .... she .2 = & osc - 5p 48 0 13 30 ft) WRISHOMM I. oc. s Se. = ee =e sen 54 0 19 30 14 | Ferguson Yellow XChisholm.........- 60 0 38 23 157) Hereuson: ¥ ellow: Se. 5-4 e0-- =~ lee 50 0 15 34 16 || WEHISROUT Sige ft sees = ot 65 0 23 38 17 | Gorham YellowXChisholm.........-- 51 0 21 32 1BilGorhant Weliow: -a0e2-s< 4.85222 .$-2.- 34 0 10 19 26 | Selection 137 -...:.5.2.-- 40 0 4 30 27 | Selection 137 x Chisholm 55 0 21 32 28 | Chisholm....... 55 0 30 20 29 | Selection 136. . 65 0 38 30 30 | Selection 136 Chisholm. 75 0 45 30 fl Chisholm. 3-c..... Pees _ 2 Se = Sao 38 0 12 27 2] SHYCIOPPOh> os... 2 St. cen eee ase = 51 0 20 33° 33 Sureroppet Chishoim==.. 9.5.23 46 0 23 23 $2) Chisholm... 2) Sees Oo ee ese 35 0 14 18 B84) BIDW.< -2 eee. 2 P.-E 51 0 15 34 39 Bir >< Chisholm sae)... = S45 eee 63 0 25 41 40 :@RisholnN .. .- 5 cates on eee 48 0 22 26 AL \ Gourd Seeds... er: - Le: ee 66 2 40 25 42 | Gourd Seed XChisholm...-..-....-..-- 68 0 56 15 43 oe Rie SOS 2 1 epee oe. CS dee ty et 35 0 10 23 AA Manson 32-22. |. 5419-6. 7 -ake et Be 45 0 26 21 45 Baton ne Chisholmet .. - 5.53255. Pee: 52 0 30 25 461" Chisholinic:::. Set 165-52 854-3 See 49 0 22 24 AT | Mosby Prolitic.2 0 ast eset ea ees 44 3 24 24 48 | Mosby Prolificx Chisholm_..........-- 53 5 42 13 49 OHISHOMM oc. as seen eee eee } 41 0 16 32 In 10 of the 12 comparisons the cross outyields the better parent, the increase ranging from 3 to 29 per cent; in the remaining 2 com- parisons the cross yields 18 and 9 per cent less than the better parent. TEST AT CORSICANA, TEX. At Corsicana the test was located on sandy loam of medium fer- tility. The corn was planted in hills 34 feet apart each way, culti- vated well, and kept free of grass and weeds. The planting was made in a different manner from that at Sherman and at Waco, a smaller number of rows of Chisholm were planted and these were 218 TESTS IN TEXAS. 35 arranged so that two of the crosses were planted adjacent to the same row of Chisholm. One of the crosses (Schieberle x Chisholm) was cut by mistake when green and fed to stock. The order of planting the varieties and crosses, and their field-row numbers, together with the results of the test, are shown in Table XI. TaBLe XI.—Comparative productiveness of parent varieties of corn and first-generation crosses at Corsicana, Tex., in 1910. {Area of each row one eighty-sixth of an acre.] Yield of ears (husked). | Number of ears. =! Male Suck- ow Tart stalks ers Tn- Wa: Variety and cross. per per bs Per | cTease aa Tow. Tow. i over ood. | Poor. row. | stalk. Rotten | parent. Pounds.| Pounds.) Per ct. 7fe|| Asis 10) ee ee ae oe ae 74 6 Zoe | Or SL Ts pa me na 24 32 8 | Singleton XChisholm.................. 76 2 24 foo2 2 27 37 RGIS OUUA ooo ee Ss prea oe seins fasion 70 4 204 220d leak oes 28 28 10 eee noun SME Ea 78 0 27 346 11 32 30 DI MCO@HNOUPH . oasis oe net ni a 2 75 2 234 016 Ree 30 33 i2apwergusonm Yellow. 22 s.605.25. 2h 20 b>. 83 0 344 BUG; |Eeoyes aes 40 35 13 | Ferguson Yellow XChisholm..........| 83 0 32 386 —7 40 30 ie) | (GlsCSti) eae ee ee ee eee 84 4 264 BING) ene 30 33 15 | Gorham Yellow XChisholm........... 77 0 304 396 21 40 31 ee Gorham: ellow=.. 2. <.-2-55-00. 252248 69 0 22 BLO) eek ae? 20 40 PMEMOIBCHIONM GO 2 4... 2382 =e gel 83 0 35 LA ee ae 48 28 18 | Selection 136xChisholm_.......... ... 80 5 35 437 4 40 36 19 Ue ae aaa e eee bec area ee 65 0 22 Beis Seaeeee 23 30 20 | SureropperXChisholm...............- | 87 3 354 408 —2 40 40 ZA EGO] 0) 0,2 an ee 79 0 33 ALS, |e -$- 420 36 43 em eparvbapcns 222s eh We eo eee oS | 78 2 34 BSG) (ER oe S22 44 28 23 | Dan Patch Chisholm... .........5..- 84 12 39 464 6 | 38 47 wae) (Cstsiye haps sn oe es ae 85 3 30 C23 tal koe pase 35 38 Zaeelow . 22.7... 4... 282. - 5... 95 5 344 363 —2 36 48 ROMMENO Wisc eects ec ecsde- hee Se SL. 77 3 25} SLO ee eee ae 26 40 Zfawweavsortne Valley =. 282% nbn ae aso | iD 2 30% 407 |) eee 26 34 28 | Lily of the Valley xChisholm........- 74 0 393 534 31 51 26 POU MU AISH OUT) ino 8 eR S S 67 5 26 OBB Ale econ 28 30 30 | Gourd Seed XChisholm............... 78 a 34h - 442 7 40 36 PRI MOCLOUIEGUS COGS co ccd ae age 76 0) 314 eS eee | 28 41 BPA] fb Toh 15 6 ae dpe te ao Oe 77 3 254 aooly (Senos 28 40 oo) Munson Chisholmt.,.. 6. - 2.6 << =< 2 =. | 84 4 303 363 —2 32 43 Sgiill (Ointl Ve) bac te ea Sie ae eee | 76 0 27 DOD | oes 35 30 35 | Mosby ProlificxChisholm.............| 85 8 34 400 6 52 27 SONPMOSHy PIOMNEH 2 ones see eee ee 81 11 274 S40h Ee eemens 52 30 avo |eshivanti i kya a one: ae 68 0 25 368')|-seoeeee 30 28 38 | Selection 137Chisholm._.............. 77 0 284 370 — 2) 32 36 32)1) CONG) iri eee eee ee a 75 3 30 ADO) ||: saetacte | 28 34 22 pA CATT STING) NOL id pe MME et 77 4 23 32,! lal Cee ese 24 44 A/a) Eouiiman Chisholm .2.9.5222 2%. 2... 2. 79 8 214 272 —14 24 44 MERE AILS Se soem en. See nee oe | 77 0) 18 | YAY Sener 16 36 The cross outyields the better parent in 8 comparisons out of the 14, the increase ranging from 2 to 31 per cent; in the remaining 6 com- parisons the better parent outyields the cross by 1 to 9 per cent. THE THREE TEXAS TESTS CONSIDERED COLLECTIVELY. In considering the three tests collectively the relatively higher production of the Chisholm variety (male parent) at Sherman than at Waco and Corsicana is apparent. At Sherman it outyields the cross in 9 and the female parent in 10 out of 15 comparisons. At Waco it 218 386 CROSSBREEDING CORN. outyields the cross in but 2 and the female in 5 out of 12 comparisons. At Corsicana it outyields the cross in 4 and the female parent in 5 out of 14 comparisons. The results at Waco and Corsicana are prac- tically a reversal of the results with Chisholm at Sherman. The 5 varieties that outyield Chisholm at Sherman are Surcropper, Dan Patch, Seléction 137, Lily of the Valley, and Ferguson Yellow Dent. The first three varieties are earlier maturing than Chisholm; their increase in yield over Chisholm is considerably greater than the increase of Lily of the Valley and Ferguson Yellow Dent over Chis- holm. This would indicate that the superiority of the first three varieties has been due chiefly to their earliness, which made them particularly suited to the drought conditions that prevailed at Sherman in 1910. From previous experience there is reason to believe that during a normal season Chisholm would be considerably more productive than any of these three varieties. The fourth variety (Lily of the Valley) is another strain of the same variety as Chisholm, its increase over Chisholm is not especially significant, although perhaps indicating a slight superiority, as Lily of the Valley outyielded Chisholm also at Corsicana. The increase of Ferguson Yellow over Chisholm is slight, and can not be regarded as indicating very much, if any, superiority. Taking into consideration the aver- age behavior of Chisholm in all the rows in which it was planted, it perhaps should be considered as superior to any of the varieties for practical growing at Sherman. The relatively greater productiveness of Chisholm in the Sherman test than at Waco and at Corsicana is due probably to the fact that Chisholm is a northern Texas variety, and the particular strain used in these experiments has been grown for many years on fertile black lands near Sherman. This doubtless has caused the variety to be better adapted to its environment at Sherman than it was at Waco or at Corsicana. Its yields also indicate that it was better adapted to the Sherman environment than were the other varieties in the test. The higher yields of the three early maturing varieties does not seem to have been due to better adaptation, but rather that the abnormal conditions of the season were less disastrous to them than to the later maturing varieties. The increase of Ferguson Yellow Dent, itself a northern Texas variety, is so slight that no generalization is warranted that it is better adapted to the Sherman environment than is Chisholm. Of the varieties used as female parents none has been bred for any length of time for the conditions encountered at any of the three places. At Sherman the conditions were very adverse and the yields very poor. At Waco, in the Brazos Valley, conditions were more favorable. The soil retained the moisture better than the soil at 218 TESTS IN TEXAS. 37 Sherman and more moisture was available for the growing crop; higher yields were made, but Chisholm seems to be less suited to the conditions than most of the other varieties. The female parents made an increase of 223 per cent in average production per stalk over their average production per stalk at Sherman; the same increase for Chisholm is 186 per cent. The results at Corsicana were similar and as pronounced, although actual yields were lower than at Waco. As has been stated, Chisholm at Sherman, to which conditions it has been thoroughly adapted, outyielded the cross in 9 out of 15 comparisons. At Waco, planted in the deep, sandy soil of the Brazos Valley, conditions to which the variety is apparently not adapted, it is outyielded by the cross in 10 out of 12 comparisons. At Corsicana, under conditions to which it was apparently also not adapted, it is outyielded by the cross in 10 out of 14 comparisons. In the Waco and Corsicana tests the crosses in the majority of comparisons outyielded the parent varieties. None of the varieties used in the tests had been bred for any length of time for the environ- mental conditions encountered at either place. At Sherman the Chisholm variety, which has been grown for many years in that locality, outyielded the crosses in most of the comparisons. This would indicate that in general a variety well adapted to its environ- ment is not improved nor its productiveness increased by crossing with other varieties possibly less adapted to the environment. What results would be obtained by crossing varieties that have been bred in the same locality and under the same conditions for a long period will have to be determined by further experimental work. Although in this connection attention should be called to the fact that crosses with such varieties as McCullough, Ferguson Yellow, and Singleton (all established northern Texas varieties that have been bred under very similar conditions to Chisholm) are less productive than Chisholm. THE PRODUCTIVITY OF THE PARENT VARIETIES AND ITS INFLUENCE UPON THE PRODUCTIVITY OF THE CROSSES. In Table XII an attempt has been made to trace as far as the fifth or sixth rank in yield the factors showing to what extent the highest yielding crosses are progeny of the highest yielding varieties; also to what extent the highest yielding crosses may be identical with the crosses showing highest percentage of gain over better parent. Table XIII is a similar enumeration of the poorest yielding varie- ties, poorest yielding crosses, and crosses showing the greatest per- centage of decrease as compared with the better parent. In the Sherman test the six highest yielding crosses are identical with the crosses of the six highest yielding female parents, but they 218 38 CROSSBREEDING CORN. do not rank in exactly the same order as the parent varieties. The crosses showing the greatest percentage of increase over the better parent are identical with four of the highest yielding crosses. In the list of poorest yielding crosses four are identical with four of the crosses of the poorest yielding female parents with Chisholm. The crosses showing the greatest percentage of decrease as compared with the better parent are the same as the poorest yielding crosses and, with one exception, are progeny of the poorest yielding female parents. In the Waco test four of the highest yielding crosses are identical with four of the crosses of the highest yielding female parents. Of the crosses listed as showing the greatest percentage of increase over the better parent four are identical with four of the highest yielding crosses, three are progeny of three of the highest yielding female parents, and two are progeny of two of the poorest yielding female parents. Four of the poorest yielding crosses are progeny of four of the poorest yielding female parents. The two crosses that are less productive than the better parent are both progeny of low-yielding female parents. 218 39 *BUBOISIOD 7B 4S} OU} UI ION “OOB AA 18 480} OT] UI JON 1 TESTS IN TEXAS. 9 ees sseseeeeyong ue [ttttteceeftetteesteeee SOU AGOOTGO 5 OEE OGOE o] PEC OC ONCE MED NSAP aC OOGE COC RE |i toaeee Bence aannee area aoeHECorcc ewe to as ee OUTTOLADACSONM INO. ounce: seenkes oan CHIOUCOLOLI SMI Che | mn lean idaaaam se GC peed PANO eRe wilt wee > eee peeg pinoy TL RT cage alas ie DOASIDINON) |AGro we | ss ass aes P ‘QI WOTOoTEG | 98G° | g ‘MOT[OX UOsnsIEy | OIF’ 9 J MOT[OA WOSNSIE\T Tt | Pee SSeS EHO GET. alas cee ¢‘poog pinoy | gop: sf raise ¢‘teddoxomg | gIp: | Jeddorimsg{| Aes) Eg) FZ Pe a DOL OAMOLEUTOS NIGP OY Ohl te oe ee) ae @ Yow UBC | LEP’ F ‘9ST WOrydoToS 9ET UOTO9TEg 1 AOTIBA OU} JO AWT | FEG° PeAS TSA COnOLATA ny Ove Woles! sr sss wiecaan CenevCdaGea |kOche: ili =. 2. :ueue youed Usd L Shigpioadelesmae kere 4 opraqaryag [terete cin winicis cn cuRR bea emeaatee ciate oil lfc tale we eller wee nenes Cuesta batee eee epee eee J Ge ll ea: aa Tee DOGSUDIOS)! IWEGG: celina’ Sess ose PF OlLaq OUTOS \|,G.G" 92) |"= "Sse & ‘QET WOLDoTeg 981 WODeTOg 1Z [MONO UOSSIOM: |\nenes) L|Pat eee @‘ogT womoojeg | Gogg: sss oo- 7 ‘efmeqeruogs | 9zG: 2 |- Sacjhcloimenyi{ 008 M ma a ah ACTOR COD ee” | Treen Skeeter GOMLOSUNT OG || re ae ner ie ieslets ZRULOSTOUAT ROGGE alles “nec bi caiaae a mWOsUN\, 62 hye hao) pao hile|| Wrc(t)o os | pe iets TcpsosipIMOy): |pegoe Pest se oe oe Te Dees PIO: |PeRG loces foes ween posg panor) pee Ca, chins 9 ‘LET WOTJORTOS | LLT* g ‘poog pinoy) "Terese" * poses pinoy ee oa Pinca Pees PMO EIaLy seeeeee es ="§ 9ST UOT}O8TOg c 9ET WOTo0[oS ; ibe de toe Aeon SIV EST s Bea CA SUN O ATL Lbs ms, 3 t AcqTeA ort JO ATPT|)---.----... uvuLeyg ese OS ee 0 eT Coes ee Dace eee ae ee ae eee cele — ie isi al GET WOHOOPOS | LHD fe ERO Me RCT Cree De @ ‘reddosoing | 880 fn *roddoromg WU? lad “Spunog “spunod “Spunod “IBIS 3 “TRIS ; “TRIS “urey) “(mmpoysTyD X) AVoIe A rod sien rod 2M rod “AYOUB A pax | PUP (wpOYsIyD X) Aone A prearx | Pe (ulpoystyO X) Aone A DIOL : “AYTROOT “‘quered 10140 IOAO OSBOIOUT 5 ha 3 *(ssouaAtOnpoid Jo 1ap10 jo ose} Uo010d YSstTY SuULMOYS ssoIg sso0 SuypIeyA-431H SENG) ur ‘surporA ysoq) yuored oyeue7 2 in| “OI6T ‘spxay, ur ‘squasnd Burpjarh ysaybry ay2 07 asnaiour fo aboyuaosad ysaybry burnoys sassoua pun sassoio burpjarh ysaybry ayy fo uoynjay— |X AAV], A s i) <) o “4 — a eS) = = = 2 R fe) = ) 40 “asBold0(] uosunyy “*** L8T WOToeTog ““MOT[OA WOSNSIO CBee omieas tea rae oe uvwyny{ uosunyy uoJe[sUIS uel yy 5 Fe ER opoqaryag “"*-OUTO1g Aqsow “(ampoystyD X) Ajorre A “‘quered 10}40q Woy oSsverd0p Jo osvjusoled ysty SULMOYsS ssorg “OOBM 4B 4804 UL ION 1 £98 re RAIA SR aeaocre “OL ‘uosunyy 2£9¢ —” ‘Wires dee Saas ape eo ate “OT ‘MOL See, S|). ae “7 LL Susnoymn gow Zeek © [awww eww nen encase “ZI: “101 0] ulg ls Ob imncsiaee a aiis €1 ‘ueulyn yy O6F 6° ele et owe tt ec cece g ‘sno TNO Ww SP Cs (CC ee a aay 6 ‘MOTE 1) lg ieee ihe ot ‘1eddos91ng rae, Fite TI ‘optord Aqsow RB a ae ay ZI ‘LET Uo}oa]0g RMS Se oi ala le TT ‘uoqo[sutg Al es Cs ZI ‘uosuny|, ee Ramla £1 ‘OpHoId Aqsow (Vas ae ad rie PI ‘olreqoryos tho : ee ey FI ‘ueuygnyy a pd “yu pparx | PUB CatfogstyD X) AQoreA *SSO10 SuLp[orA-100,4 £98 Ce Co i ay OT ‘MOTEL 968° ocr 2-22) KOTO we 104) A ay Calon ZI _Wojopsuts GP A ee eee “TT “sno Moon, ZLZ° seen ASOT ‘uBUyn EL or = [aww ww wwe weet eee - 6 ‘MOTEL a, a i Seapets 11 ‘OpHod Aqsoypy J)! Sih Ie aes “9 ‘MolfoX WeyIOH 1) ie ahead: 8 “ysnoTINOoW Pi GI ‘LET Wor}o0]0g Rae Ba oe IT ‘uojoysurg al Cs (CS ee ZI ‘mosuny|, FFI Cs Cf aa 8 ‘MOT. TT eae a | ae “eT ‘OUHOId Aqsow (LOM UA a eR ea PT ‘uBugN “Spunod phe “yues prota | PUB CwMToYstYD X) Aor A *ssorg, A cere - MOLE OLGR. — \likvas paeguee MOT[OA WBYIOH Ce 25 ||iec akon boo caana WOJO[SUIS a apie “ysnolIngoW peg7 [toe BSR rere ueMyn yy ere freee RESET OE Cee rier MOLE PORE TN, Ipieeag eee ouord Aqsow PEGE | jthissisesiscie’s MOTOA WBYIOY (UT Saal dllg Seg pane ease es ysnor[npoW OG Pe a cig yeaa LET WOrOeTOg GIL” £60° BRO? [eee t eet e teste ee eens MOTE LO eget aee Shae '2= oppor AqQsowW 6z0°0. [ttre Belen | UeWAN FL *Spunog “BIS Jod *AYONIV A PIOLA *(ssouoATjonpoid jo JopsO OSIOA UI Ul SuIperA 4so1o0d) yuored opeure,y “7 "**"""BUBOISIOD Bis(ule se sw id\e/a --"OOBM “AYITROO'T ‘OL6L ‘spxay ui sjuasd burpjarh ysamo) ay) 07 asnasoep fo abnyuao.ed 480jn016 burnoys sassouo pun sasso.o burypjarh 9 sano) ay, fo wounjay— TI IX ATAV 218 TESTS IN TEXAS. 4] In the Corsicana test four of the highest yielding crosses are pro- geny of four of the highest yielding female parents. Among the crosses showing the greatest percentage increase over the better parent three are identical with three of the highest yielding crosses, two are progeny of the high-yielding female parents, and two are progeny of the poor-yielding female parents. Of the poorest yield- ing crosses, four are progeny of four of the poorest yielding female parents. Out of the crosses showing the greatest percentage of decrease from the better parent, one is the progeny of the poorest yielding female parent, and two are the progeny of two of the high- est yielding female parents. Two are identical with two of the poorest yielding crosses. It is evident in these tests that in general the most productive crosses have come from the most productive female parents; that the crosses showing the greatest percentage of increase over the better parents are in most instances identical with the highest yield- ing crosses. Likewise, in most cases, the poorest yielding crosses are from the poorest yielding female parents, as are also most of the crosses that show the greatest percentage of decrease in yield. There is no instance in which one of the highest yielding crosses springs from one of the poorest yielding female parents. There are, however, both in the test at Waco and at Corsicana, two crosses (Gorham Yellow & a ka: aati tag oe) oe ee er Oy ake Sc isPos: 2.8 st L ne Tee eee PP eG Dea san 5 Sta er 8 pe oy py ae 8 ee oe A ere UG haan e Ee EEN a ps Se gaa ote 6 ae rere aire pee th eee. sae "<5 0) ol ae Bethe Re | eS : P cm" Ee : 6 Sear) 2 eo el sda) * € ein SST “ee OD Sy ie ie Sane | Sau amt id (el |e aa 4 eet "3.18 ; Brine oa sa dahil cade ! me" ST ; ol Nal 9 A § 5 ea wae ep eg OAl pale mee YL oe a 28 i gee 8 Hap Nhe «fh ears OT ig aoe ‘2 ig p pees gi ce ut. g a | ae E L rae a oe eae Bost *L WoljoIg “9 MOONS *¢ WOTJOIS *p UOTJONS "g MOTJONS *% UOTONg *T WoLjoeg [oyorg O10q {IBY YIP ssoso s}t pue uosuIETTTA ‘A {UOC OVA SIOSPOY YIPAA SSodO S}T PUB MOSUUVITITM “Q ‘(SMOI AT) OYTOId O1OGTIVW YATA\ ssoso S}I PUB [OTOPOU MA “F “FUE OTYM SiOspOY YIP ssoso S}f pus La eb ‘g foyloid O10g|IBY YIM ssoso Ss} puw [epuny “Yy ‘UEC SYM Si0SpoOyY YPM ssoso s}t puew [Span x?) POY UIIM Ssoso S}T PUB MOTIIA UONTIS ‘O foYOId CLOG [IVP WIT SSOJO S}T pUB OYTOIg Sdopuvg ‘vy ‘yued ATM SIeSPOY UIA SSoJo S}I PUB OYTOLg SiopuBg ‘Pr LOYOId OLOGTIVIY YIP SSOI Sj PUG JUOT OFM SIOSpoY “T “UOT OTA SIOSPOY YALA sSsolo ST PUB YUE OFT M S1OSpPOy ‘y ‘oyTO1d O1OGTIVW ILM SSOsd S$} PUB OIOGSO}BIG JO OANCN ‘f ‘ued MMM SIOSpOY YALA Ssoso S}T PUL O10GSO}L}Yg JO OATVN ‘7 SOYWOId OLOGTIVIY YILA Ssodo Syt puw OyOId Aqsow ‘7 {yuaq ei S103 pox WIPA\ Ssoso sz pus oyTorg Aqsoyy ‘Y ‘oyTOId OLOGTIBW YPM SSOJO $}T PUB OYTOIg OLOQ WIV ‘7 *}UOCT OU M SLospOY YITA\ SSOJO S}T puB OY TOId o1OgUeAy “7 {oYTO1d OOGTIV YILA\ Ssolo st pus oyTorg exo0g ‘Gg ued SYA SiodpoOrY YALA ssoso s}L PUB OYTOId OY00D “OD ‘OYTO O1OQ[IV, UIA SSo1O S}T PUB WOT}OeIOg wuUpry ‘_— {UE MAA SIEspPOY YIPA SsolO s}T puB UOTOAI0g YOUpPTY ‘V :(Z JO 4dooxo YOwo JO SMOJ OT PUB Yowo JO sivo QT) AUOZOId Polqsso1o ITOY} PUB SEToLIBA OY} 0} soy} ‘sina fiuaboud pougsso.o ayy pun usoo fo sina paiq-aind yourbio fo OT6T us ssauacyonposd ayy Bursndwmoo sof synjd buysay fo unjq—% WVAOVIG 218 TESTS AT STATESBORO, GA. 49 CONDITIONS FOR GROWTH. The land had been thoroughly plowed several weeks previous to planting. Just before planting, furrows were opened with a large shovel, which not only permitted planting below the level in moist earth, but also helped to throw to one side hidden obstructions that might interfere with a uniform thrust of the hand planters used. A marked wire was used to regulate both the spacing of the hills in the row and the spacing of the stalks in the hills. The writer_and his assistant planted all of the seed. Each man carried seed for a certain member of the hill only, and together they planted each hill, On removing the planter from the ground the foot was placed upon the spot and the weight of the body was thrown upon it in stepping forward to the next hill. Care was taken to remove trash or any other obstruction that might interfere with proper planting. Nine square feet per plant were allowed, so that very little compe- tition for sunlight was possible among the plants. The rainfall was abundant except for a week or 10 days previous to tasseling. A liberal supply of commercial fertilizer was used. Abnormal growth (barrenness, smut, etc.) was very rare among the plants, but there were missing members of some hills and a few missing hills. However, in securing the data that follow, considera- tion was taken only of hills that grew under normal conditions and whose members seemed to have had equal opportunity and were normal. MANNER OF HARVESTING. The harvesting was done by four men. One carried a notebook and kept all of the records. Another carried a knife and selected and cut the hills of a row that were suitable. The other two men took the stalks as they were cut, one carrying the first member only and the other carrying the second member only. The fodder was thus collected and carried to the end of the rows and there weighed, and the collective weights of the two members of each hill were recorded separately. The ears were then separated from the stover, and the weight of each together with the number of ears was recorded. MOISTURE IN GRAIN HARVESTED. Through the courtesy of the Office of Grain Standardization mois- ture determinations were obtained of grain shelled from many ears of each variety and each cross. The extreme variation among the varieties and crosses was less than 2 per cent of moisture. The shelled grain of Aldrich Perfection and Whelchel contained 16 per 218 50 CROSSBREEDING CORN. cent of moisture, and the other varieties and crosses contained about 1 per cent less. The appearance of the large cobs of the Whelchel and Aldrich Perfection varieties and the rotting of the ears indicated that the entire ears of these varieties contained a greater excess of moisture than did the shelled grain. In these two cases a correction for moisture content would give a more valuable comparison, but since the moisture content of the entire ears was not determined the comparisons of productiveness are in all cases based on the weight of ears as harvested. PRESENTATION OF RESULTS IN GEORGIA. DATA COLLECTED AT HARVEST. Table XVI gives in detail the data collected at harvest time in 1910. TABLE XVI.— Yield record of 11 warieties of corn and their crossed progeny tested at Statesboro, Ga. ALDRICH PERFECTION ? XK MARLBORO PROLIFIC ¢.1 Weight of product (pounds). Number of ears Seed “ber Total Per stalk cent oer ear of Kind of product. : ; of ; Origi- Origi- Differ- Origi- nial Cross g Cross ate Cross. 1 ys 9.75 9. 50 0.70 0.68 | —0.02 — 3 15 14 i 13.75 14. 25 -98 1.02 -04 | °° AY coe eee 2 eae 4. 25 5.00 - 53 . 63 -10 18 8 ° f sae 6. 25 8. 25 . 78 1.03 »2 5 Yi eee) |i ie = 2 3 12 ars §.75 (23) . 48 . 60 -12 26 Le 12 S124 iis | Sas ee ee 8 12.00 - 58 . 63 -05 9 24 28 es . 89 -91 -02 1 |S eee (eee 9 12. 50 - 43 . 60 ah. 39 21 30 , s 19.75 . 69 .94 . 25 SOME cme se eee 10 18 {ean ho ae a Oat Eat 11.00 Lao .61 . 65 . 04 it 28 23 ‘Sa a 18. 25 17. 50 1.01 .97 | — .04 =F soe ee eee 1 Favoring the cross: Ears, 7 out of 10; stalks, 9 out of 10. Average weight of ears per stalk produced by the female parent, 0.54 pound; by the cross, 0.59 pound. Average weight of stover per stalk produced by female parent, 0.83 pound; by the cross, 0.95 pound. Increased yield of cross over the female parent: Grain, 10 per cent; stover, 15 per cent. 2 Favoring the cross: Ears, 7 out of 10; stalks, 4 out of 10. Average weight of ears per stalk produced by the female parent, 0.51 pound; by the cross, 0.55 pound. Average weight of stover per stalk produced by female parent, 0.81 pound; by the cross, 0.83 pound. Increased yield of cross over the female parent: Grain, 8 per cent; stover, 2 per cent. 218 52 CROSSBREEDING CORN. TasLe XVI.— Yield record of 11 varieties of corn and their crossed progeny tested at tatesboro, Ga.—Continued. CocKE PROLIFIC 9 X RODGERS WHITE DENT ¢.! Weight of product (pounds). Number of ears Seed Nom my 4 m produced, ear | of Kind of product. otal. er stalk. No. a 1s. Origi- Origi- Differ- Origi- oe Cross. rift Cross. | “ance nat, | CTOss. 1 6.75 5.75 0. 52 0.44 | —0.08 13 13 12.00 9.25 92 tl. | — 621 | Sepa eee 2 9.25 | 10.00 ~ OL . 56 . 05 18 20 14.00 14. 50 -78 -81 03 | . dightit. St Ss2eeeeeeee 3 9.00 | 10.00 - 43 .48 . 05 22 22 ‘ 12.75 | 15:25 - 61 aoe 12) . ot R05 eee 4 8. 25 7.00 - 46 .39 | — .07 20 18 14. 25 10. 00 .79 -56.| — .23)|,. =30N. 222 eee eee 5 5.75 4.25 .48 .35 | — .13 13 12 8.75 6. 25 -%3 52.| — 21), pie eS eee 6 6. 25 6.75 45 - 48 . 03 16 14 : 9.75 | 9.25 70 -66 | — .04\) ests ae 7 10.25 | 10.50 49 «50 ol 22 21 16.25 | 15.25 77 213) — «04)),, =e lee 8 11.75.) 13.575 51 - 60 09 28 31 17.00 | 19.50 74 .85 11) . Mb 4s225 See 9 9.00 9. 50 43 ~45 02 25 22 14.50} 16.00 69 .76 O71). “Beh 2a 10 6. 50 7.25 - 43 - 48 05 16 17 9.25} 10.50 62 -70 08 | .d4 02st h-2ueee MARLBORO PROLIFIC 2 X MARLBORO PROLIFIC ¢.? 1 11.00 0. 51 0.52 0.01 2 27 27 17. 25 -90 .82 | — .08 = Oil): Soo eee 9 11. 50 «DL . 64 -13 24 19 25 18.75 -81 1.04 23 yh ee en, 3 12.00 S02 | = heOr 05 9 25 28 21525 . 88 1.01 13 1685. See e eee 4 8.00 . 54 -40| — .14 —26 22 30 13. 25 -81 -66 | — .15 I$: -T5.4.|- beans 5 6. 50 ~ 52 -43 | — .09 —16 20 16 11.25 - 88 .75 | — .13 =155: DAS eee 6 10.00 .47 - 53 06 11 23 22 15. 25 oe . 80 09 134: .- 22 .5-|-22 eee 7 12.25 44 - 56 ol 26 26 33 19. 25 . 69 . 88 .19 WGile 2 seeks be oes 8 14. 25 46 SOR. 11 24 29 38 21.75 .78 - 87 09 12): = 2 os2|beareeee 9 10.75 -53 -47 | — .06 —12 30 26 | 17.00 . 83 -74 |] — .09 S4l: Seb eee 10 9. 25 - 43 -40 | — .03 —8 27 24 13.75 .70 -60 | — .10 144). eel eee 1 Favoring the cross: Ears, 7 out of 10; stalks, 5 out of 10. Average weight of ears per stalk produced by the female parent, 0.47 pound; by the cross, 0.48 pound. Average weight of stover per stalk produced by female parent, 0.73 pound; by the cross, 0.71 pound. Increased yield of cross over the female parent: Grain, 2 per cent; stover, 2 per cent. 2Favoring the cross: Ears, 6 out of 10; stalks, 5 out of 10. Average weight of ears per stalk produced by the female parent, 0.49 pound; by the cross, 0.51 pound. Average weight of stover per stalk produced by female parent, 0.80 pound; by the cross, 0.82 pound. Increased yield of cross over the female parent: Grain, 3 per cent; stover, 2 per cent. 218 TESTS AT STATESBORO, GA. 53 Taste XVI.— Y eld record of 11 varieties of corn and their crossed progeny tested at tatesboro, Ga.—Continued. MARLBORO PROLIFIC 2 X RODGERS WHITE DENT ¢.! Weight of product (pounds). Num- Per Number of ears Seed} ber cent produced, ear | of Kind of product. Total. Per stalk. of No. aia differ- S. Origi- | Gross. | Orig | Gross, | Difter-| °°” | Origi- | nal. “| nal. SS: | “ence. na gnGES 7 13.25! 0.58} 0.53|—0.08| —9 33 28 OAS We teGeila OK --c Gs |) eS lshec acl oe 5 Ton: (4814 2541 208 12 28 7 SOO) Seine 196) ~ 215 ie 922 ea ae ‘ Toles fsa, c5ee| e208 4 29 7 23.95} .90| 1.06| .16 Te 2 ae 7 De e 1s pe 158 60") 2 02 3 37 7 26.75 | 1.05| 1.07] .02 rsd ae” > Riven ; IGG she le esd]. rox 8 27 28 B00 et ion 210 14 ie a + ‘ Wog le. isa. 257) °..05 9 28 8 21.00} .88| 1.00| 12 ileal | Rael), Sey . iste aaltepet eit 26 29 28 Slee We. .OR || 19 51 hat aan |) DHE F Gee Lalas Shel =O eo 29 om) (obsar les ALG homie: ce reer ee ae 5 1050. (Sao 258 200 0 22 20 mop igal. i938) 02 cll 2 Me ROA a i 1G see eA az 33 15 22 15 Toe: Sete eset 290 pe i © eae | See : 15 85 34 oul i 4 34 30 25 24 25 3 j Vt, | eee) Saas | | See f 31 22 26 5 c Te Nee 5 i 19 i9 i8 9 i9 i : Oi els ie : 8 8 rhe! Papal | Beneae : | ae in peters ob ee 22 2 9.00 | 10.00 39 43 04 11 3 25 Biman rt aati oe 18.00 | 18.00 78 78 00 i) sd ane eal 1 Favoring the cross: Ears, 7 out of 10; stalks, 8outof10. Average weight of ears per stalk produced by the female parent, 0.53 pound; by the cross, 0.57 pound. Average weight of stover per stalk producea by female parent, 0.93 pound; by the cross, 1.01 pounds. Increased yield of cross over the female parent: Grain, 7 per cent; stover, 8 per cent. 2 Favoring the cross: Ears, 10 out of 10; stalks, 6 out of 10. Average weight of ears per stalk produced by the female parent, 0.49 pound; by the cross, 0.55 pound. Average weight of stover per stalk pro- duced by female parent, 0.85 pound; by the cross, 0.89 pound. Increased yield of cross over the female parent: Grain, 13 per cent; stover, 6 per cent. 218 54 TasBLe XVI.— Yield record of 11 varieties of corn and their crossed progeny tested at Seed ear No. O66" NI VERE Oe eo Oh = i=) 63 OD ETL a) GS a a C0 PUN et — oS CROSSBREEDING CORN. Statesboro, Ga.—Continued. Mossy PRouiFIC 9 X RODGERS WHITE DENT ¢.! Weight of product (pounds). N Lol —= Pha er n n of Kind of product. Total. Per stalk. of po — differ- ills. ence, Origi- | , Origi — Differ- nal, | TSS: | na Cross. | ‘once. 18 | ars. 6.75 | 10.00 0. 38 0. 56 0. 18 48 2525] Lc ees Seo eee ec 13.00 | 15.75 Gre . 88 . 16 21 7 Ears. 6.75 8. 25 - 40 -49 .09 22 Bialik... 2 84 Lie Secs 11.25 | 12.25 . 66 ota - 06 9 22 Ears.. 8.75 12. 50 «40 Pry Ae ig 43 Pi ariesees: See 5 aS 14.75 | 20.25 . 67 .92 = 20 37 18 1Op rae 9.00 | 11.50 - 50 . 64 .14 28 Bibs... 3 Sees .c See 14. 50 18. 50 - 81 1.03 -22 28 22 Ears... 8.50 | 11.00 . 39 . 50 yi! 29 Rigike®], Sastre 14.25 | 17.50 . 65 . 80 -45 23 20 {ea ene acatae | eee 8.50 | 11.50 - 43 - 58 ~15 35 Stabs cot Sow lea 14.75 18. 00 .74 - 90 . 16 22 22 Warsss. 10. 25 12.75 47 . 58 ae 24 Stalks 3.32222. -- ose 17.25 | 20.50 . 78 - 93 -15 19 23 {sain =e 10. 25 13. 00 ~ 45 . 57 ae 27 Opals sane eee 19.50 | 21.75 «85 - 95 -10 12 18 WATS conde aoe ee cena: 10.00 | 10.75 . 56 - 60 -04 8 Stalks: 224 20 tee 16.75 18. 50 - 93 1.03 .10 10 25 {ee PSR oes eae 10.75 13. 75 - 43 . 55 -12 28 cis eae ee ee eee 20.25 | 23.25] .81] .93] .12 15 NATIVE OF STATESBORO 9 X MARLBORO PROLIFIC ¢.2 g) |fPars------------------ 13. 25 12. 75 0. 63 0.61 | —0.02 —4 Stalks: 2: 232° 5222225 21.25 | 20.00 1.01 -95 | — .06 —6 20 i Dr ee ee 10. 75 11. 50 . 54 .58 . 04 it i Stake == 2 seo = Se eee 17.50 | 18.00 . 88 - 90 . 02 3 pipiens” oo? ee ee 3.25| 3.25 . 46 . 46 00 0 Gistlics: = Seen eee eee 5. 50 5.00 .79 -71 | — .08 —9 23 | MATS Se oee pee eae 11525 | 12:25 -49 .53 - 04 9 Siaiks:: <2 2 Sesh 18.75 | 21.50 - 82 - 93 Syl 15 21 aise 22-22 2-2 2th 9.00 | 10.50 - 43 . 50 - 07 17 Sialks-cs so ee ssi eee yo) zeus 73 . 85 .12 16 13 | Wars... fc 55 2es2es see 7.00 6.75 -54 .52 | — .02 —4 Stalks) < oP pe 2h st eee 11.00 11. 50 . 85 . 88 - 03 5 15 Wars Soi peee cece ae 25 7.00 . 48 -47| — .Ol —3 Stalks: ..<. 2222522 = $251) 2-0 Py (3) .73 | — .02 —2 10 | LOC peace ene ess 6.00 6. 25 - 60 - 63 - 03 4 (SIDER eso csc see 10.00 | 10.50 1.00 1.05 - 05 5 18 | Marsh: 2-5 7.75 | 10.00 - 43 . 56 213 29 Slalksts tee so teer ceo A3425 |) 15.25 .74 . 85 ri 15 13 QUIS Sea cee ete esae ees 6.75 7. 00 - 52 . 54 - 02 4 Stalks. eas aaa 9.75 10. 50 Wo: | . 81 . 06 8 Origi- Crom. 25 23 ie ia 70 oii a Bi as ai |e ae ae ae cette ie ae sim ai} 7" 6 is 3) ata 38'| "a0 22 23 ie stem Se ‘tite a 24 [777785 Sits of bi ilies ial] ae i ig} G6 Si: Tinie bo ai: ig} do ie ig [id 1 Favoring the cross: Ears, 10 out of 10; stalks, 10 out of 10. Average weight of ears per stalk produced by the female parent, 0.44 pound; by the cross, 0.56 pound. Average weight of stover per stalk produced by female parent, 0.76 pound; by the cross, 0.91 pound. Increased yield of cross over the female parent: Grain, 28 per cent; stov: 2 Favoring the cross: Ears, er, 19 per cent. 6 out of 10; stalks, 7 out of 10. Average weight of ears per stalk produced by the female parent, 0.51 pound; by the cross, 0.54 pound. Average weight of stover per stalk produced by female parent, 0.83 pound; by the cross, 0.88 pound. Increased yield of cross over the female parent: Grain, 6 per cent; stover, 6 per cent. ’ 218 TESTS AT STATESBORO, GA. 55 TasLe XVI.— Yield record of 11 varieties of corn and their crossed progeny tested at Statesboro, Ga.—Continued. NATIVE OF STATESBORO 2 X RODGERS WHITE DENT 7¢ 1 Origi- nal. Weight of product (pounds). Per stalk. Differ- Cross. ence 0.50 | —0.13 -85 | — .18 . 61 -O1 1.03 | — .O1 . 66 - 00 ie aL - 00 50 | — .08 79 | — .23 . 62 - 06 1.03 . 06 «55 05 -95 | — .10 - 46 - 02 79 | — .04 nut aly .99 -23 Aina) . 20 . 93 . 29 - 46 - 00 . 80 12 RODGERS WHITE DENT 2° X MARLBORO PROLIFIC 3.2 ced) per ee er ear | of Kind of product. Total. No Breet ro Origi- | Cross nal. Sage i 7.50 1 15 12.75 2} a 3 a 1b | a < | 28 6 11 10. 0 7 18 if 5 10. 50 8 19 18.75 9 22 {Stalks Cie | eatin 14.00] 20.50 10 21 ars.... -— 9.75 9.75 Staiks==—) Seo. Se 14. 25 16.75 1 18 iS ee 10. 00 10.75 Siaks ctf Pe ae Se 15.50 16.75 2 22 lie a eS See ee 11.50 | 11.00 SE Ree — see a es 16.75 17.00 3 19 ESE Rael | eee eae 9.75 | 12.00 SUS NS = See SA 15.75 | 19.00 4 21 (sp ee = ee a 12.00 LTS Sips ee 17.50 18.75 5 25 STSe.. Sap ee oni ae 11.75 | 13.00 Se See ee 18. 25 20. 50 6 17 OC nae (aes Gee t00)) 10625 iaikss.- 2 88o— ce 12. 25 15. 25 7 22 107) Se ee ee 10.00 | 10.50 Btslks oars oc a: 15. 45) 6215 8 17 10-0 The SAR Ree pe 9. 25 9. 25 Sialksts sate 2. Coe te 14. 50 14.75 9 12 LUT gee | eee ae Be, See 6.75 ‘SiC ERAS 2 cage Se 8.00 11.00 10 17 HATS ei. seme ee 8.50 9. 50 SEALS toes ce ee 13.50 15. 00 8 8 —4 1 23 21 —2 7 11 12 37 24 5 6 0 2 28 38 12 11 Number of ears produced. prlee Cross. 17 15 MM i9| 7 | (2 A ec Ise 5 1a St a 19°14 5 wa i! inh say Nt og ve ee gee ee 13) ho a0 ier: i9| 19 i2e op aaliy cae Stir Dit 1 er 18 24 1a. O85 ta ee ne OF | 45 ee ih ae Oe | fa may, it as aL hy REO iF iy Mette iy Al | De 1S 17, |i, 9 ba 13 | de ise 19) 14 ee 1 Favoring the cross: Ears, 6 out of 10; stalks, 4 out of 10. Average weight of ears per stalk produced by the female parent, 0.51 pound; by the cross, 0.54 pound. Average weight of stover per stalk produced by female parent, 0.88 pound; by the cross, 0.92 pound. Increased yield of cross over the female parent: Grain, 7 per cent; stover, 5 per cent. 2 Favoring the cross: Ears, 7 out of 10; stalks, 10 out of 10. Average weight of ears per stalk produced by the female pement 0.50 pound; by the cross, 0.55 pound. e duced by fema parent: Grain, 10 per cent; stover, 12 per cent. 218 Average weight of stover per stalk pro- parent, 0.78 pound; by the cross, 0.87 pound. Increased yield of cross over the female 56 CROSSBREEDING CORN. TasBLE XVI.— Yield record 11 varieties of corn and their crossed progeny tested at tatesboro, Ga.—Continued. RopGERS WHITE DENT 2 X RODGERS WHITE DENT ¢.! Weight of product (pounds). Number of ears Seed er ce io ear of Kind of product. Patel. Per atalk, £ No oda differ- lus. ence, Origi Origi- Differ- Origi- tg tos a) A leet oe Cross. 1 4 Ros 2 5 Rh dos 4 7.00} 5.25| 0.64] 0.48] —0.16| —25 13 i Stiles: fee eae. 11,35] $.95.)0) 1.02 .75 | — .27 | 27) |e--=--2-|-t-rene= 9 i (PRS. 2c FE. 13.25 | 11.25 .58 dQ |= !00) |) neal 28 25 Btalie:.- 2. 8) -/c: aie 21.25 | 17.00 92 74 | — .18 |\...=90) =-=-- oe 3 ig (es 2 EP 795) 6% 52 43°) — 200 |\.. 14 14 alice: ee 11.00 | 10.75 .79 S77 || —~ 02) ||, Saige See eet sere 4 pet |p = == Fee 2--or ee 13.25 | 13.50 . 60 61 01 2 31 28 Stalice: . 10:| . .=2°9}|/ Ree 6 13 oe See SS Pee FT 7.00] 7.25 54 56 02 4 14 18 Sisiks:. | S265" oe 13.00] 12.25] 1.00 94 |. —..06 |. 16ers 7 17 (Marses-. - 23-25... 5 = 9.75 | 11.50 57 . 68 11 18 21 23 Sinlks:. 3.66.2. tae 15.00] 17.50 .88 | 1.03 15 174 ee 8 29 ee Be Ga bee 12.00] 10.50 55 AS |= 07a 25 22 Stalks... 2 64... 2 20.00 | 20.00 91 91 00 0: 9 7 ee io. ee ER 4.00 4.25 57 61 04 6 i" 9 Gtalizsts 0 205 bee 7.25} 6.50] 1.04 £93 |) = <1" |). . Sa008 | Bees ee 10 | (tess eee eee se 11.00} 10.00 61 £58) =. 05a eee 21 Siabicns., Spb! oe 17.00 | 15.50 94 -86)|\ —. .08: |. 2191/2 ae 1 Fayoring the cross: Ears, 3 out of 10; stalks, 3 out of 10. Average weight of ears per stalk produced by the female parent, 0.56 pound; by the cross, 0.51 pound. Average weight of stover per stalk produced by female parent, 0.88 pound; by the cross, 0.80 pound. Increased yield of cross over the female parent: Grain, —8 per cent; stover, —9 per cent. 2 Favoring the cross: Ears, 6 out of 10; stalks, 3 out of 10. Average weight of ears per stalk produced by the female parent, 0.57 pound; by the cross, 0.59 pound. Average weight of stover per stalk pa by female parent, 0.94 pound; by the cross, 0.96 pound. Increased yield of cross over the female parent: Grain, 4 per cent; stover, 3 per cent. 218 TESTS AT STATESBORO, GA. Be Taste XVI.— Yield record oh 11 varieties of corn and their crossed progeny tested at tatesboro, Ga.—Continued. SANDERS PROLIFIC 2 X RODGERS WHITE DENT ¢.! Weight of product (pounds). gent | Per | Number ofears ale gl Total. —_| Per stalk gent, |~ | PREM ear of Kind of product. 2 $ ‘ of No penect | differ- ills. | ence. | Origi- Origi- Differ- | Origi- Sar Cross. ag Cross. aids. A Cross. ee 4.75 5. 00 0. 48 0.50 0. 02 5 10 il DROIES ae eee a ne ee 6.75 7.25 - 68 73 . 05 a] |e ec eg Ser 2 20 aES 2 Ae setae aan ee 9.50 | 11.50 - 48 - 58 - 10 21 21 23 IBEKS ee oo ore 14.50 | 18.00 -73 - 90 17 Ne IE Eee ae (eee See 3) 15 LOE eee ae 150) 10525 -50 . 68 18 37 16 19 Biatks: 2. S52. 2 oe 12.25 | 16.00 - 82 1.07 25 FT| [23 geen es) eta ae 4 18 ATS 23 5 Pie once es 9.75 | 10.50 54 -58 04 8 19 21 S17.) ee eens 14.75 | 18.00 . 82 1.00 18 POTN pee | bet pe 5 | 2.50 2. 25 - 63 -96 | — .07 —10 5 4 5. 00 3. 50 1. 25 -88 | — .37 2 Nal ees) Meee = 6 10.00 | 12.50 - 50 . 63 13 25 21 23 15.00 | 20.00 75 1.00 25 o 2 Tl Reames Pers aeeee 7 8.25 8. 25 -55 -d0 00 0 20 16 11.25 | 12.25 5 - 82 07 OSs re .Alecee ces 8 10.25 | 10.25 -57 -O7 00 0 21 | 21 15.00 | 14.75 - 83 -82 |) — .01 B= )3| |S See Rae 9 9.50 | 10.75 - 45 SL 06 13 22 25 14.25 | 17.50 - 68 - 83 15 PAD ee Nee toe 10 23 ATS ee ere =e SIE 10.50 | 12.25 - 46 -53 -07 17 24 23 Sie ae eee 16.00 | 19.25 -70 . 84 -14 NOM se case, al eee = © X MARLBORO PROLIFIC ¢.2 1 13.75 0.49 0.72 0. 23 49 20 31 20. 50 - 82 1.08 26 OQANE 2: Se sa Beeteaee= 2 10. 25 49 49 - 00 0 23 | 23 16. 00 81 76 | — .05 0) eee ate! bes pester 3 140 57 -92 | — .05 =—.9 19 18 11.75 - 97 -78 | — .19 at hy eee poi e ae 4 8. 00 -49 -47 | — .02 —3 18 23 12. 50 76 74 | — .02 ae ka Seeeaaee \soose)sa05 5 10. 50 46 -55 - 09 20 19 23 17.25 68 91 23 Sot less Se a3 (ese shee 6 10. 00 47 3 - 06 11 20 | 21 15. 00 76 79 - 03 Bi Soe sel eee eae 7 6. 00 46 50 - 04 9 12 15 11.00 73 92 -19 Abaleee sees leew ees 8 9.75 56 54 | — .02 —3 18 | 18 5 15. 00 85 -83 | — .02 =a Dates? AE zeta 9 15 LUE ie Bore ened os 7.50 | 10.75 50 72 22 43 15 24 SU a ees 1150s) L5.%5 ds 1.05 . 28 By Col | Sebati res 10 “Fy | oe eee ae a 10.00 | 10.50 53 | 55 . 02 5 25 | 23 UARKS eo ce eats ee 14.75 | 16.50 78 | 87 - 09 2 PE cee eye 1 Favoring the cross: Ears, 7 out of 10; stalks, 8 out of 10. Average weight of ears per stalk produced by the female parent, 0.50 pound; by the cross, 0.57 pound. Average weight of stover per stalk produced by female parent, 0.76 pound; by the cross, 0.89 pound. Increased yield of cross over the female parent: Grain, 13 per cent; stover, 17 per cent. 2 Favoring the cross: Ears, 6 out of 10; stalks, 6 out of 10. Average weight of ears per stalk produced by the female parent, 0.50 pound; by the cross, 0.56 pound. Average weight of stover per stalk produced by female parent, 0.79 pound; by the cross, 0.87 pound. Increased yield of cross over the female parent: Grain, 12 per cent; stover, 10 per cent. 218 58 CROSSBREEDING CORN. TaBLE XVI.— Yield record of t 11 varieties of corn and their crossed progeny tested at atesboro, Ga.—Continued. STATION YELLOW 9 X RODGERS WHITE DENT 7.1 Weight of product (pounds). aoe — Bor Nene ae Seed! ber cent P , ear | of Kind of product. Total. Per stalk. “of No. eg ; differ- s. | ence. Origi- Origi- Differ- Origi- a Cross. | “naj Cross. | ‘ence. 7 Cross. 1 16 (ean nee. 2 1 ae. 2 8.25 8.7. 0. 52 0.55 0. 03 6 17 17 DIES. Se wc eee 13.00 | 14.00 - 81 . 88 - 07 de Se) eee 2) 29 Mane. 3. coe oa cae 11.75} 15.75 . 53 72 -19 34 24 24 Siakks: 2). t 3355. es 20.00 | 26.50 -91 1. 20 29 | 83". 2 s scieec |e eee 3 | 18 res me bi CB 11.00 | 10.50 - 61 -58| —.03| —5 20 19 } BLGEKS oo. 3. Seek. ee oe 19.25 | 19.50 1.07 1. 08 -01 | 112) 32a ae) as eee 4 19 (eon So ee 10.00 | 11.00 - 53 . 58 - 05 10 23 19 Stalks: 222... 2c 16.50} 18.25 . 87 - 96 - 09 bl eee ee ee 5 | | Se ee ee raed. 9.50 | 13.25 . 43 . 60 BY eT age 26 Sere | ts) << a i md 14.00} 19.7 . 64 - 90 - 26 re eee eee 6 | 19 {Sean See BAe 11.25 | 12.25 . 59 . 64 - 05 9 26 21 | Bis. 3- Ses. toes 19.00 | 19.50 1.00 1. 03 - 03 el Eee ae a 16 {Sea at ee oo ee 8.75 8.7 - 55 - 55 - 00 0 16 16 SiMKS.. = wee ace ee 15.00 | 16.00 -94 1.00 - 06 T las. see] =e 8 21 (gant ae do eee op ee | 11.75 | 13.50 - 56 . 64 - 08 | 15 21 21 Sg 5 6.25 | 6.50 . 48 .50 - 02 | 4 14 15 10.25! 9.75 .79:|-. 275 | —.04 5 |2:: 2) eee 5 | 6.50| 10.00} .38| .50/ .21| 54 17 19 10.50 | 17.25 62| 1.01 39 | 64.22: SEA ees zy 8.50} 8.50 50 .50 00 | 0 18 17 13.00 13.00 76 . 76 00 | 0 |2.: | WILLIAMSON Q X RODGERS WHITE DENT ¢2? | ! - xy OE casas 8.50| 9.50} 0.47] 0.53] 0.06 12 | 19 21 Sisiks!.. ee 15.50 | 17.50| .86 .97 ea 13'|!.:488.1|. Se : on | teen Bas ees Le 10.75 |- 14.75 49 . 67 .18 | 37 22 28 Spalikss 2se. obs 18.50 | 25.75 84] 1:17 . 33 | 39'|...3222.5|eeee 3 18 on ee ee ope TAS 10.50 | 11.00 58 3 ee) 5 19 20 Stalks:..5. 212. eee 16.75 | 17.50 93)|.caacOTdl iw .04| 4|..252-2:| ee ‘A PA | (cnet 11.50) 14.50 30 . 63 .13 26 26 22 NStalette hse et: 20.25 | 26.00 roy hm ee | meas 28" sees eee 3 4 [Rare Rene Bee 6.75 | 7.50 48| .54| .06 11 14 15 ? [2 a See 11.25 | 12.50 .80| .89; .09 fijos: 5 2h|aeeeeee 6 16 er POE LP ee 7.00 9.00 77 ee J) ee 29 16 16 SEalkS! 5 oy eee 11.75 | 15.50 S73:\5 S07 | * 324 32,123) Bo laa 7 6 (eae ae 3: ee 3.75 | 3.25 .63| .54) —.09| —13 7 6 \\Stalks-.-.225.<-* 20g 6.75 | 5.50} 1.13 192 | =.21 "| fo) P as (eae SpE SS eae 5 4.25| 5.00| .53| .63 .10 18 9 8 2 ae a I 6.75| 825| .84] 1.03] .19 oe = P 15 [Barge oes ooo 7.75| 800| 152] .53| OL Zh aie 15 I\Stalks-- 2 ees. -. <3 xe 13.00 | 13.00 | 87 £87;|-~ A008) Diilkce eee 2 Seen 10 13 ieee ater She heated 32 7.50 | 6.75| 50| .45| —.05 10 15 15 Stalks) <. fee 12.00 | 12.00 | 80} .80| .00 Olas: 2. eee 1 Favoring the cross: Ears, 4 out of 6; stalks, 3 out of 6. Average weight of ears per stalk produced by the female parent, 0.46 pound; by the cross, 0.54 pound. Average weight of stover per stalk produced by female parent, 0.76 pound; by the cross, 0.87 pound. Increased yield of cross over the female parent: Grain, 16 per cent; stover, 14 per cent. 2 Favoring the cross: Ears, 8 out of 10; stalks, 7 out of 10. Average weight of ears per stalk produced by the female parent, 0.50 pound; by the cross, 0.58 pound. Average weight of stover per stalk produced by female parent, 0.85 pound; by the cross, 0.99 pound. Increased yield of cross over the female parent: Grain, 14 per cent; stover, 16 per cent. In Table XVII a comparison of the effect of crossing is made between the varieties as a whole, when crossed by Marlboro Prolific and when crossed by Rodgers White Dent. The percentage of increase or decrease in yield of the cross is given, and also the number of rows out of 10 in which the production of the crossed ears was greater than that of the original 2-year-old seed of the female parent grown in the same hills with the cross. 218 TESTS AT STATESBORO, GA. 61 TaBLeE XVII.—Summary of the 10 ears of each variety tested with their crossed progeny. Marlboro Prolific sire. Rodgers White Dent sire. Increase of cross over 1908 seed of Increase of cross Female variety. over 1908 seed of | Rows favoring Rows favoring the cross. the cross. female parent. female parent. Ears. | Stalks. | Ears. | Stalks. | Ears. | Stalks. | Ears. | Stalks. 'Percent.| Per cent. Percent.| Per cent. Aldrich Perfection. ........-- 12 — 6 6 5 10 15 7 9 Speke ve roune.. 2.2. ..2-52-..- 8 2 7 4 Z —2 7 5 Marlboro Prolific............. 3 2 6 a 7 8 7 8 MesDy EOC. ....22--->--.- | 13 6 10 6 28 19 10 10 Native of Statesboro.......-. 6 6 6 7 7 5 6 4 Rodgers White Dent......-.- 10 12 7 10 -—8 -—9 3 3 Sanders Prolific.............- 4 3 6 3 13 17 7 8 Station Yellow...--..-.-..-..- 12 10 6 6 | 13 13 if 9 UDG Ey pe ee ed SEs eee — 3 —2 4 6 | 7 7 7 8 VOU eo | 16 14 14 13 14 16 8 rf General results. .......- | 4 6.9 | 6.1 | 9 | 9 6.9 7 1 Only six rows considered. Table XVII shows that when crossed with Marlboro Prolific all but one variety (Tindal) gave a gain in ears, and all but two varieties gave a gain in stover. When crossed with Rodgers White Dent all varieties except the sire variety itself gave a gain in ears, and only two gave a loss in stover. SOME CROSSES SUPERIOR TO EITHER PARENT. Since the yields of the crosses are compared only with the female parent, it might be concluded that this general higher yield of the crosses is probably due to the still greater productiveness of the male parent. This conclusion, however, is not supported in the cases where Marlboro Prolific and Rodgers White Dent serve as females in the experiment. In both instances the resulting cross produced better than its female parent and since Rodgers White Dent is more productive than Marlboro Prolific, as shown in Table XVII, the cross in which Rodgers White Dent served as female must be con- sidered more productive than either parent. In Table XVIII is shown the average ranking of the varieties according to their productiveness in 1910 in the test plats at States- boro, Ga., where each variety was grown in the same hills with its crossed progeny. TaBLeE XVIII.—Arrangement of varieties of corn in the order of their productiveness, as indicated by the average yield per stalk when grown in hills with their crosses. ps Ears per | Average 7 ite Ears per | Average Name of variety. at ae Name of variety. ar Ser Pounds | Pounds. Manners ievolitic 2. -.22222021 0. 535 1 Native of Statesboro. -......-.- 0. 51 4b Aldrich Perfection............ .53 2a || Station Yellow................ Sok 4c Rodgers White Dent.........-. aoe 26: ||\(CockelProlifie. “23-4 22422224. 32 -49 5 SUT oe es eae -515 3 Williamson 2552. -2-- - Beas ub - .48 6 Marlboro Prolific............-- 51 4a\\| Mosby ‘Prolific: 225223222293. t=" 2465 7 218 62 CROSSBREEDING CORN. It will be seen that seven varieties equal or excel Marlboro Pro- lific. When these seven varieties are crossed with Marlboro Prolific as sire six out of the seven first-generation crosses exceed the Mar!- boro Prolific in grain production, and five in stover production. It will also be seen that two varieties equal or excel Rodgers White Dent. When these two varieties are crossed with Rodgers White Dent as sire both of the first-generation crosses exceed the Rodgers White Dent in grain and stover production. It will thus be seen that out of the 20 crosses made 8 have given grain yields greater than the better parent, and 7 have given stover yields greater than the better parent. RELATION OF THE PRODUCTIVITY OF THE CROSSES TO THE PRODUCTIVITY OF THE PURE STRAINS. It is a striking point in connection with the foregoing table that all those female varieties giving more productive crosses than either — parent are grouped at one end—the upper end—of the ranking list for production and with but one break in the rank. None fall below fourth in production in a total ranking of seven. With one excep- tion the varieties that can not be said to have given advantageous crosses with either sire are grouped at the other or lower end of the ranking list. Omitting Marlboro Prolific and Rodgers White Dent, nine other varieties are crossed by each of these sires. In six out of the nine comparisons the crosses with Rodgers White Dent are more productive than those with Marlboro Prolific. In view of these points and the fact that Rodgers White Dent is more productive than Marlboro Prolific it is found that the pro- ductiveness of both parents seems to stand out clearly as a factor in influencing high yield in first-generation crosses. The Tindal variety, however, is a striking exception to this seem- ing tendency. The rank of this variety is third in productiveness, but when crossed by Marlboro Prolific its yield was actually less than its poorest producing parent; and when erossed by Rodgers White Dent the cross was less productive than that sire. Because of this exception, this apparent tendency can not be relied upon as a guide in the selection of suitable varieties for practical crossing. ADAPTATION AS A FACTOR IN THE PRODUCTION OF HIGHER YIELDS THROUGH CROSSING. As the difference between the lowest and the highest producers is less than 5 bushels per acre, it would seem that it might be ques- tionable to dicuss this subject with the data at hand. In justice to the subject, however, it should be stated that the appearance of the corn produced indicated more variability in adaptation than do the weights. 218 TESTS AT STATESBORO, GA. 63 It is interesting to note in this connection that the variety Mosby Prolific is farthest from home, that it has been carried to a more radically different soil than any of the other varieties, and that it is ranked lowest in yield and failed to give a practical cross. Cocke Prolific is the next farthest from home, ranks third from the bottom of the list, and was impractical for crossing with either Marlboro Prolific or Rodgers White Dent. The Williamson corn ranks next to Mosby Frolific; as it had been given considerable selection at home for years, it is reasonable to suppose that its low yield is due to poor adaptation. It is thus seen that three out of the four varieties that were imprac- tical as crosses with either of the two sires were also poorly adapted to the conditions at Statesboro. The Tindal variety again stands out as an exception. INFLUENCE OF SEASONAL DIFFERENCES. In 1909, while the crosses for this test were being grown, a careful comparison of the varieties was made. The season was different from that of 1910, and the effect is clearly shown by the ranking obtained at that time. The ranking for 1909 was: DS ie Tindal. Sib de, Samara aa Williamson. Decond. .. 220 Station Yellow. Seventh st). JliSie4 Mosby Prolific. (6) Native of Statesboro. | Highth.......-...... Aldrich Perfection. Molmthmee se oo. - Rodgers White Dent. | Ninth...............- Cocke Prolific. Mtilat REN See 2 LEE Marlboro Prolific. | Pemtheiis i LeO 2 Sanders Prolific. Apparently the difference between the two seasons has resulted in changing Sanders Prolific from last to first in rank and Aldrich Per- fection from eighth to second. The first year less difference in pro- duction was shown between the two sire varieties than was shown the second year. In 1909 Mosby Prolific (poorest in 1910) ranked better than Aldrich Perfection (second in 1910). Tindal ranked high both years. The differences shown by the two tests are radical, but hardly more than is frequently found in variety tests of more than one year. If, as has been previously indicated, there is usually a relation between high yield and adaptation and the advantageous crossing of corn, then it would seem that seasonal differences may play an important part. | INFERENCES DRAWN FROM THE FOREGOING DATA. From these tests it would seem that the productivity of first- generation crosses is usually correlated to the productivity of the parent varieties, and the yield of the parent varieties is largely dependent upon their adaptation to the location and the season during which the test is made. 218 64 CROSSBREEDING CORN. As seasonal differences have a marked effect upon the comparative production of varieties the success of a cross one season may be found fleeting if continued. The fact that the variety Tindal in its adverse performance toward crossing has rather emphatically ignored all the influences of rank and adaptation that seem to govern other varieties may indicate that advantageous exceptions may also be found; but whatever further investigation may demonstrate, present knowledge indicates that the economic increasing of corn yields by means of crossing is attended with many complexities. GENERAL CONSIDERATION OF ALL THE TESTS. INDICATIONS OF INTERMEDIACY, As the varieties crossbred at the various points are varieties that have met with general favor as grain producers, the characters of the male and female parents of each cross are not radically different, and consequently any intermediacy of a cross is not as apparent as it might be if the parents were much unlike. However, in many instances intermediacy between the two parents was observed regard- ing various characters; such as productiveness, height of stalk, length of growing season, and percentage of moisture. Averages of many crosses usually indicate intermediacy, because exceptions in one direction from the median points are offset by exceptions in the other direction, but under the conditions of these and other tests of this nature so few instances have been shown in which the first-generation crosses produced less than the average of the two parents as to indicate that the average productiveness of first-generation corn crosses is usually above the average of the parents. It may be that this indication will not be found entirely due to advantages regarding adaptation, age of seed, self-fertilization, etc., that most of the reported tests t have given to the first-generation 1 Beal, W. J. Reports, Michigan Board of Agriculture, 1876, 1877, 1881, and 1882. Ingersoll, C. L. Seventh and Ninth Annual Reports of Purdue University, 1881 and 1883. Sanborn, J. W. Indian Corn. Agriculture of Maine, Thirty-third Annual Report, Maine Board of Agri culture, 1889-90. Kellerman, W. A., and Swingle, W. T. Crossed Varieties of Corn. Bulletin 17, Kansas Agricultural Experiment Station, 1890. McCluer, G. W. Corn Crossing. Bulletin 21, Illinois Agricultural Experiment Station, 1892. Morrow, G. E., and Gardner, F. D. Bulletins 25 and 31, Illinois Agricultural Experiment Station, 1893 and 1894. Webber, H.J.,and Swingle, W. T. Hybrids and their Utilization in Plant Breeding. Yearbook, U.S. Dept. of Agriculture, for 1897. Vanatter, Phares O. Annual Report, Virginia Agricultural Experiment Station, 1906. Shull, G. H. The Composition of a Field of Corn. Report, American Breeders’ Association, vol. 4, 1908 Also A Pure Line Method in Corn Breeding. Report, same, vol. 5, 1909. East, E. M. The Distinction between Development and Heredity in Inbreeding. American Natu- ralist, vol. 43, No. 507, 1909. : Collins, G. N. The Value of First-Generation Hybridsin Corn. Bulletin 191, Bureau of Plant Industry, U.S. Dept. of Agriculture, 1910. Increased yields of Corn from Hybrid Seed. Yearbook, U. S. Dept. of Agriculture, for 1910. Hays, H. K., and East, E, M, Improvement in Corn. Bulletin 168, Connecticut Agricultural Experiment Station, 1911, 218 EES ——— = GENERAL CONSIDERATION OF ALL THE TESTS. 65 crosses, and that further work with all conditions more nearly equalized will demonstrate a general tendency for first-generation crosses to pro- duce better than the average of the parents. Such a general tendency might be due to prepotency of the higher yielding parent. It is more profitable to grow the higher yielding parent except in cases in which the first-generation cross produces better than either parent. Since some first-generation crosses are more productive and some are less productive than their better parent, the greatest benefit can be obtained by planting such as may be found more productive than the highest yielding variety of a community. PERCENTAGE OF MOISTURE IN SHELLED GRAIN OF CROSSES AND PARENT VARIETIES. Because of care in allowing the ears of all varieties to dry thor- oughly before yields were weighed it has not been necessary to calcu- late corrections for moisture content except in the Maryland tests. The moisture content of shelled grain from a large number of ears of each variety at each point was determined by the Office of Grain Stand- ardization of the Bureau of Plant Industry. Regarding this char- acter, averages as given in Table XIX show the first-generation crosses to be intermediate between the parents. TABLE XIX.—Average percentage of moisture in shelled grain of crosses and parent varieties on dates when yields were weighed. | Average | First-gen- Tests, jects wae of both | eration Bil * | parents. | crosses. | Maryland......-. ES nae See oe ge oS ee CS ee EEO | 27.29 28.77 28.03 28. 32 Saliernines a. eo. 3 Sete, Se ee ee 10. 22 11.74 10. 98 10. 90 (REE Sais caenee oo (aoe eee SEE eee ee = eee ee et ee 12.39 11.45 11.92 12.13 JLDVEN..... Lone ae ee ee ee ee eee 15. 40 15.01 15.21 15.00 HE GIST Grr ee = Se eee Be Se eee Rees ee 16. 33 16. 74 16.54 16.59 UNRELIABILITY OF AVERAGES FOR SPECIFIC INSTANCES. With investigations of this nature the investigators as well as the readers are desirous that the work should discover some law of nature. However, the development and evolution of plants furnish so many exceptions and variations to even general laws that it is impossible to foretell the effects of crossbreeding particular varieties by the effects secured previously from crossbreeding other varieties. Types, varieties, strains, ears, and even kernels of corn contain in their lineage such complexity of structure and characters that it is not surprising that this work, necessarily of a preliminary nature, should unfold more problems than it solves. The results are interesting because they contain evidence in sup- port of various theories, but the chief value of the work is its indi- 218 66 CROSSBREEDING CORN. cation of what can be accomplished in the field of research and more especially in establishing methods of producing high-yielding seed corn. The influences that show with the greatest uniformity in these tests are those of acclimatization and adaptation. The results given here of these influences will be combined in a future publication with results obtained in other localities showing the effects on maize of acclimatization and adaptation. In studying the effects attributable to crossbreeding it is necessary to recognize the effects due both to acclimatization and to adaptation. The distinction between the effects of acclimatization and of adaptation is brought out in the tests of identically the same lots of seed in Maryland and in Cali- fornia. In Maryland, because of their acclimatization and adaptation some varieties produced much better than others of the same growing period which were brought from distant States. None of these varieties were acclimated to California conditions, though some of the earliest maturing, which were least productive in Maryland, were most productive in California. Their early maturity proved an adaptation which enabled them to escape the later and drier part of the summer. In Texas, varieties that have been subjected for years to practically the same climatic conditions indicate different degrees of adaptation to clay soils and to sandy soils. Tests of this nature thus far reported indicate that first-generation crosses usually produce better than the average of the two parents. It is not certain that this is entirely due to the advantages that these tests have given to the crosses regarding age and vitality of seed, or to the year of adaptation and selection incident to growing the crossbred seed under the same environment in which the test of productiveness was afterwards made, but to which the parent varieties were not adapted. If further tests should show that with all conditions equalized there still exists a tendency for first-generation crosses to produce better than the average of the two parents, it might be taken as an indication that the higher yielding parent is usually prepotent. A production better than the average of the two parents, unless it be better than the production of either parent, would furnish no practical method of originating strains superior to those already existing, except in cases in which the crossing might originate strains that combine or nick better than previously existing straims. When all influencing factors, such as age and maturity of seed, acclimatiza- tion, and adaptation are equal, and the first-generation cross is more productive than either parent, it is a clear instance in which a prac- tical advantage is derived by crossbreeding. Variations found to apply to varieties are also found to apply to different ears within a variety when they are crossbred and tested separately—in other words, some ears are crossed with another 218 GENERAL CONSIDERATION OF ALL THE TESTS. 67 variety advantageously and some disadvantageously, though in general there is a tendency for the different ears of a variety to respond similarly to the crossing. Another line of work being con- ducted by the Office of Corn Investigations indicates that what has just been said about the crossing of one variety with another also applies to the crossbreeding of individual plants within a variety. Just as certain pairs of varieties combine or nick advantageously, while other pairs nick disadvantageously, so some pairs of individual plants nick advantageously, while other pairs nick disadvantageously. This shows the results obtained by crossing two varieties without reference to individual plants to be but an average of the results that would be obtained by crossing many individual plants of those varieties. The average results may be an improvement over either parent and still fall short of what could be obtained by restricting the crossing to the individuals that nick most advantageously. In connection with this consideration of crossbreeding, it is inter- esting to note that such varieties as Selection 119, Selection 160, and Chisholm, which are among the most profitable varieties for their respective localities, have not been crossbred or mixed with other varieties for many years. The same can be said of leading strains of corn of other localities, and their merits are doubtless largely due to effects of selection, acclimatization, and adaptation. The results of these tests show that with corn some first-generation crosses are more productive than either parent, that some are inter- mediate between the two parents in productiveness, and that some are less productive than either parent. They also show that the determination of the particular first-generation crosses that can be most profitably grown is attended with so many complexities that careful tests must be made in a locality before the farmers of that locality can be intelligently advised whether it is to their interest to continue planting a pure-bred strain, or to plant a first-generation cross of certain strains. In crossbreeding corn for practical results it seems the duty of State experiment stations and of corn breeders to determine what two varieties nick to best advantage in producing seed for different environments. Whether the yearly production of a particular first- generation cross will be found advisable, or whether its use in making other crosses will be found more profitable, must be established by further work, and perhaps for each individual case. Progress in producing higher yielding strains of corn depends upon the proper combination and application of the effects of acclimatization, adapta- tion, crossbreeding, and selection. 218 »® a - Srey if sleee ae ss a 7 ul om bhig Ndeucnes + cece Gaeibl at Cherieguatay = alr Ee. Sintec) Auwretaltis ail! cA Dirge ia - ee eS Bled Aree to 9s! joe... cageourry oift of heater NM taibitsgeddcetacihcl esodagite yn bey pee wie a Gin teers Vict say bo —uein se vy treble eae ay ter tat 4 (GEihe tassel: tashdodet Ws gia ‘wt i "gawhs:roep hired bai sist it 6 SruthY SeSeO Wb aia a eg a= lashireiael jaws sarge? eludes) ey iba eee ne irhe-sweotroerbuestl: doity ater illic athe liana , Tate S59 pow ity gt bonnie de elie ; piscpae Tb td hxc nut jie? wh > ee Levheveted Asa sdb x ‘ af grb lire. Duss babost Page fs ints ina 743 ‘ove ioteles Gea vi beecll it, ‘ 5 - - - ’ p +s > sigs ) oe -@4 in i of DA i's ci $i 28 rein i+ oft ART Ire "Ss an ¥ 7+ ‘ on win } jee FRR Mo] Picii at Uae s i 7 pi ieeirtmloih thee ahd Uriel, ok ae i +i" ortesons ty sovhess Disco MEP ier ee ‘ as — 7 iv ; ten lie egbeo ees nie Ars Tat 4 e a x oliinttoeer geo Gt Hite Sar ae » » * 4 ~ - az i i » \ Gar ear ” rath Astopis Tad = é A ; $25 : Lye FtEAS Cait. | 24 r See ait F > wicnm ab aa eee ‘ ‘ ' fae Sanifoos, opie ps | 3 Eeet s re S34 o> PAT “eel q 3 Hh oVSiGu Ini ae ’ 7 : ? ince ep" ate ichh4 iin fat Sy Fyihidivey IS ey aa : fs vey 8 F . 4 ‘ } 3% i% . . — - ~“ See e ; iff iat * ¥ 2< tat 3 i Ot ea *r + : | sca | fs ‘ SL etre we F a ~ 4 3 | ' 7; > a peo “peels oly Renae as ws L iM . bb siiaoiecok irae sige nepiives Ls 4 INDEX. Page Acclimatization, factor in the production of higher yields of corn...........-- 7-9, 18-19, 27, 30, 36, 63, 66-67 See also Adaptation. Adaptation, factor in the production of higher yields of corn..............--.. 8-10, 18-22, 28-30, 37, 62-63, 64, 66-67 See also Acclimatization. Age of seed. See Corn, age. PU IMUMACCI LCE, VATIOUON Ol CODD. 2 oe. 5 = snjete ene acc oie Cacia H a. =24-5= 22m sas bee 10, 31 Tests in crossbreeding corn, general consideration. .......-....------------- 64-67 See also Corn, Experiments, Yield, etc. Lexas, adapted varieties of COrs oo. «2-2 sae ee- on tenance samen Ae 10, 31, 36 testa int crossbreeding Cota. .< sc2ee3 sep Seo ons esa 30-42, 65, 66 Vanatter, P. O., on.crossbreeding corm: =: .--::::2:22:2220:55 0-505) 64 Varieties of corn used in tests - Sb ceckttesn aces tebe ae ne oe te 10, 12-15, 17, 18, 23, 25, 26, 28, 31, 33-35, 39, 40, 42-45, 47, 48, 50-61, 63 See also Corn, varieties. Virginia, adapted varieties of corn : .. -....- -+------0--+<-65--56— eee 21-22 Vitality of seed corn. See Germination. Waco, Tex., tests in crossbreeding corn. See Experiments. Washington, D. C:,; source of varieties of Cor: - 222222 5.56264 .05-e55e eee 10, 19, 46 Webber, H. J., and Swingle, W. T., on crossbreeding corn............-...-- 64 Weevils, damage to varieties of com. < . -..4 2202-2 U.¢2:-2e4- oe 0b oe eee 42-44 Yield, comparison of crosses and parent varieties of corn. ......-- 12-30, 3242, 50-67 See also Grain and Stover. factors influencing productiveness of corn. ..-----. 7-9, 19, 22, 28-30, 62-64, 66 218 O eos DEPARTMENT OF AGRICULTURE, BUREAU OF PLANT INDUSTRY—BULLETIN NO. 219. B. T. GALLOWAY, Chief of Bureau. AMERICAN: MEDICINAL LEAVES AND HERBS. BY ALICE HENKEL, Assistant, Drug-Plant Investigations. IssueD DECEMBER 8, 1911. WASHINGTON: GOVERNMENT PRINTING OFFICE. 1911. . = oe 4 me ra Ve ea LP ul oy - e " > < ee : RSeey? 5: 10 THIMTAATIE > ve 9 Pr ~' ou ak? ‘ ; RE BUREAU OF PLANT INDUSTRY. Chief of Bureau, BEVERLY T. GALLOWAY. Assistant Chief of Bureau, WILLIAM A. TAYLOR. Editor, J. E. ROCKWELL. Chief Clerk, JAMES E. JONES. DRUG-PLANT, POISONOUS-PLANT, PHYSIOLOGICAL, AND FERMENTATION _ SCIENTIFIC STAFT. Rodney H. True, Physiologist in Charge. A. B. Clawson, Heinrich Hasselbring, C. Dwight Marsh, and W. W. Stockberger, P H. H. Bunzel, James Thompson, and Walter Van Fleet, Experts. j Carl L. Alsberg, H. H. Bartlett, Otis F. Black, Frank Rabak, and A. F. Sievers, C€ W. W. Eggleston, Assistant Botanist. S. C. Hood, G. F. Mitchell, and T. B. Young, Scientific Assistants. re Alice Henkel, Assistant. G. A. Russell, Special Agent. 219 2. LETTER OF TRANSMITTAL. U. S. DEPARTMENT OF AGRICULTURE, Bureau or Piant Inpustry, OFFICE OF THE CHIEF, Washington, D. C., April 15, 1911. Srr: I have the honor to transmit herewith and to recommend for publication as Bulletin No. 219 of the series of this Bureau the accom- panying manuscript, entitled “‘American Medicinal Leaves and Herbs.’ This paper was prepared by Miss Alice Henkel, Assistant in Drug-Plant Investigations, and has been submitted by the Physiolo- gist in charge with a view to its publication. Thirty-six plants furnishing leaves and herbs for medicinal use are fully described, and in some instances brief descriptions of related species are included therewith. Of the above number, 15 are official -in the United States Pharmacopeeia. This bulletin forms the third installment on the subject of American medicinal plants and has been prepared to meet the steady demand for information of this character. It is intended as a guide and refer- ence book for those who may be interested in the study or collection of the medicinal plants of this country. The first bulletin of this series treats of American root drugs, and the second of American medicinal barks. Respectfully, Wo. A. Taytor, Acting Chief of Bureau. Hon. James WILson, Secretary of Agriculture. 219 3 ao ae if i ‘ _ Soe = nea 7 7 Rett a } 7 4 ] - ie 7 a € : o} wton wilt a ty ungnetl GANT Yo oahiae off? Tor (PE ce A bi ‘1 , (bali §ffAaortee bites TOTES ‘rat Lost} ik ealh yh bowery), say, 196 Se a ¥ Gmilyvd hottie Pr Ae Pim te eee eB spawn k ae ~ Bao ee Sat sory wt Cire Hath & 2 wiidenri) stig | 1 pay taste boone sinless 08 11 et 4 bea tal j nl 7hhaa 57! ; , ’ ia es : ; ; ail rij mm £4 hi “age Sy print hes Ts, ras it [etn ema oo sae sind Ww ahi ; att mw Meanph, yon 2 c é ~ CONTENTS. I TE re a= on yin ee os aa asia a se wae Soe 2m Ve yl ee RR MNEMERIC MEST CR ATG SIGE «oo oa aici vik ne sete lan) a nce Die oa ches =nps op etna aia Plants furnishing medicinal leaves and herbs. .-................------------ MeEMnOREC OIL PLOT PErCOTINa)- =~. 2- -..< = oe <= Fe mane ass > eee meeriett (Hepatic hepatica and. H.-acuia) S22: 32.22. 28225. 2 siesta ME MenetHe ( CMCMAONTUNE TU0IUS) -- 2. Senvne tes SQL opiet'e 2a elas abies. Ee oe SO SRAZEL CLAMAIMCHS VL GUNA) aan anemic s an aan as ye ceed a Dee hee Sn etreRTIPENIR, ( CURSUL TROTUCTOIE) == 02 Re oes Reo no ap a Soins nots oa os Preemine primrose (Ocnotherd Otennis) = === 2 a oe one ai eee ren Mrceniaraiit (HMOdiClyOnN CALifOTNicuin). ...-..- + --=--- qe 05+ ones ep oe meena Chumapniua wmbellata)... 22.0024. 2-2.t0 2 kee. he bee ceee se Mmm tare! (Karina latifoled).. =. sso: = a0 sae = teow as tates anaes Rrmnee pm BLd (CP RETOOL TOPICTS) == Sesh psi oma ca le aaa 2 ni ain gad info al Miamterercen (Gavliheria procumbens). ~ << iio. 2-2 eo win oid em eee nae os SMEMICENCY CATELOSIA DINIIOS UUO-UTSD) aa a me a aaa as 2 ww ys en = eS wade ai ipmetsbean | Menyantics- iryoliata)... 22.22.22 5-.2---- esses see naa ne SenCNCUiciario laberiporn) 1252222 0s e225 ee ata at eee Oe FRORChOMaGy (MOTT OULTE DULG ATC) otocerat = ac « aiked -s se ees - eee MERE CTU) Ss =F ann seg SE Sid Sintec’ mike Sree wih a cas RUE RVAAED HLS COTD UNIS COTOVICE ) oo akc a asa am on fel alco eie x tsi oie ble oe estnrarrO Al (LICH COME PILLEGUOUMES) 2 = an 2 aim wine www ot5 sino ose atniajapnin ease =i Ie Weed CY COPIUS WITGUTICUS) 222.0222 Sana) ¢.e ois oe eo tans eee ae Senet MCHING-DUDCTUG) -.. 52.022 Soc ce os Bowes sesie chess -shepeee oa MMM AMICUS PPICOLD) 2 = See cae = ao 6S ha on winless nes on aie ee: SER ern WEEG f LGrRE SUTAMONUUNY) <.-) - a.- acaS 2p diosa ie eterm oiccale Arai 3 Se See MPIC CREIGIO ONTUTO ) «aa ci oa dase waa ae Bia et as oe ld Wonunon specawell (Veronica officinalis)... - <2 o-oo mini ee ea SEO VE MUFLERLIS UIMRTED).. 250 eR ys oe ae an eis Sasi = amnvenriter(MitciChia FPNCNS). i=." 62 2 Lhe eek aso gee cis slg pee MRMURMGRHCIMGMIIE TID)... 2s a2 p0iSee 2s - 2 SIRES 2 a a RE oe oe ae OMe CEL PULOTUUT DCTJOLUALUM) « - =~ = = = = 2 2 3m a2 aye opm 2 maim anna anil wep emi = Gum plant (Grindelia robusta and G. squarrosa)..........---------+------- Gaunds fleabane;(Leptilon canadense) .: 2; 2.22 =e 2G 2s d2 ke aloe = - en as = = Sime (enti lea MUI FOV) ..2 oom 3.42 os enn Doe een tae aes oe metal TANGERINE DULGGTO) << =5.2.% <3 5423. JB Aer oes Sete dae! aoe eae EMO. (A TEEIVISIA COSITENVUTIR) — an .— in ain ope win ie 22/2 gee = is da imitans s/n = MME PASSE OUMITIOTE).- . - = = 2 aia'a = aie ce Rae ai Re nae Sn aa ee = EPREUECUL CENCONUVILES MLCTRCI OUR) ow ope opm a oi wa nicks a stl aa cio Sie = Piessedinistie (Onicus benedictus)...)-> 02.2222. ete cess eee went Fic. eo hRwnNeH So 0 6 69 6o°hS NO tS NO MD wh NN ee eS ww a oO ILLUSTRATIONS . . Sweet fern (Comptonia peregrina), leaves, male and female catkins. ... . Liverleaf (Hepatica hepatica), flowering plant........---- ery . Celandine (Chelidoniwm majus), leaves, flowers, and seed pede. ‘acne eee . Witch-hazel (Hamamelis virginiana), leaves, ey and capsules.... American senna (Cassia marilandica), leaves, flowers, and seed pods. . Evening primrose (Oenothera biennis), leaves, flowers, and capsules... . Yerba santa (Eriodictyon californicum), leaves and flowers........--.- . Pipsissewa and spotted wintergreen (Chimaphila umbellata and C’. macu- lata), flowering and fruiting plants... --....-.-<- -=.-205 s--peee eee . Mountain laurel (Kalmia latifolia), leaves and flowers.......-.-------- . Gravel plant (Epigaea repens), leaves and flowers......---.---------- . Wintergreen (Gaultheria procumbens), flowering and fruiting plants. - - . Bearberry (Arctostaphylos wva-urst), leaves and fruits........-.-.----- . Buckbean (Menyanthes trifoliata), flowering plant..........-.-.-.--- . Skullcap (Scutellaria lateriflora), flowering branch, showing also seed Capsules: .... 2: co ee. ens 5 cosa ek ene ew ene eens oes ee enn . Horehound ( Marrubium vulgare), leaves, flowers, and seed clusters. - - . Catnip (Nepeta cataria), leaves and flowers........---------------- al . Motherwort (Leonurus cardiaca), leaves, flowers, and seed clusters. ...- . Pennyroyal (Hedeoma pulegioides), leaves and flowers.......-.------- . Bugleweed (Lycopus virginicus), leaves and flowers. .....-..---.------ . Peppermint (Mentha piperita), leaves and flowers....-..---.--------- . Spearmint (Mentha spicata), leaves, flowers, and running rootstock... . Jimson weed (Datura stramonium), leaves, Teas and capsules. ..... . Balmony (Chelone glabra), jeaves and flowers....-..------------- pe . Common speedwell ( Veronica officinalis), leaves and flowers. .---.----- . Foxglove (Digitalis purpurea), leaves and flowers. .-...-------------- . Squaw vine (Mitchella repens), leaves and fruits.....-.-.------------ . Lobelia (Lobelia inflata), leaves, flowers, and inflated capsules.....-.. . Boneset (Eupatorium perfoliatum), leaves and flowers....------------- : area erindelia (Grindelia squarrosa), leaves and flowers. .. =. = .aas5ee , : Yarrow (Achillea millefolium), leaves and pees ar aeS . Tansy (Tanacetum vulgare), leaves and flowers......----------------- . Wormwood (Artemisia absinthium), leaves and flowers. .....--------- 34. . Fireweed (Erechthites hieracifolia), leaves and flowering topswes-eceaes . Blessed thistle (Cnicus benedictus), leaves and flowers.......-..----- 2 Coltsfoot (Tussilago farfara), plant showing root, leaves, and flowers... 219 6 ms | B. P. 1.—669. AMERICAN MEDICINAL LEAVES AND HERBS. INTRODUCTION. Less difficulty will be encountered in the collection of leaves and herbs than in the case of other portions of plants, for not only is recognition easier, since, especially in the matter of herbs, these parts are usually gathered at a time when the plants are in flower, but the labor is less arduous, for there are no roots to dig or barks to peel. Of the three dozen medicinal plants mentioned in this bulletin, 15 are recognized as official in the Eighth Decennial Revision of the United States Pharmacope@ia. This is more than half of all the leaves and herbs included in the Pharmacopeia. Among the plants included in this bulletin are peppermint and spearmint, which are found not only in the wild state but the culti- vation of which for the distillation of the oil constitutes an impor- tant American industry. Especially is this true of peppermint, thousands of acres being devoted to the cultivation of this plant, principally in the States of Michigan and New York. A number of other plants mentioned in this paper furnish useful oils, such as oil of wintergreen, pennyroyal, fleabane, tansy, wormwood, and fire- weed. ; As in the case of other bulletins of this series, an effort has been made to include in it only such plants as seem most in demand, lack of space forbidding a consideration of others which are or have been used to a more limited extent. With two or three exceptions the illustrations have been reproduced from photographs taken from nature by Mr. C. L. Lochman. COLLECTION OF LEAVES AND HERBS. Leaves are usually collected when they have attained full develop- ment and may be obtained by cutting off the entire plant and strip- ping the leaves from the stem, using a scythe to mow the plants where they occur in sufficient abundance to warrant this, or the leaves may be picked from the plants as they grow in the field. Whenever the plants are cut down in quantity they must be care-~ fully looked over afterwards for the purpose of sorting out such 219 7 8 AMERICAN MEDICINAL LEAVES AND HERBS. other plants as may have been accidentally cut with them. Stems should be discarded as much as possible, and where a leaf is composed of several leaflets these are usually detached from the stems. In gathering herbs only the flowering tops and leaves and the more tender stems should be taken, the coarse and large stems being rejected. All withered, diseased, or discolored portions should be removed from both leaves and herbs. . In order that they may retain their bright-green color and char- acteristic odor after drying, leaves and herbs must be carefully dried in the shade, allowing the air to circulate freely but keeping out all moisture; dampness will darken them, and they must therefore be placed under cover at night or in rainy weather. A bright color is desirable, as such a product will sell more readily. To dry them the leaves and herbs should be spread out thinly on clean racks or shelves and turned frequently until thoroughly dry. They readily absorb moisture and when perfectly cured should be stored in a dry place. Leaves and herbs generally become very brittle when they are dry and must be very carefully packed to cause as little crushing as pos- sible. They should be firmly packed in sound burlap or gunny sacks or in dry, clean boxes or barrels. Before shipping the goods, however, good-sized representative samples of the leaves and herbs to be dis- posed of should be sent to drug dealers for their inspection, together with a letter stating how large a quantity the collector has to sell. With the changes in prices that are constantly taking place in the drug market it is, of course, impossible to give definite prices in this paper, and only approximate quotations are therefore included in order that the collector may form some idea concerning the possible range of prices. Only through correspondence with drug dealers can the actual price then prevailing be ascertained. PLANTS FURNISHING MEDICINAL LEAVES AND HERBS. Each section contains synonyms, the pharmacopeeial name (if any), the common names, habitat, range, descriptions, and information concerning the collection, prices, and uses of the plants. The medicinal uses are referred to in a general way only, since it is not within the province of a publication of this kind to give detailed information in regard to such matters. Advice concerning the proper remedies to use should be sought only from physicians. The state- ments made in this paper as to medicinal uses are based on informa- tion contained in various dispensatories and other works relating to materia medica. 219 PLANTS FURNISHING MEDICINAL J.EAVES AND HERBS. 9 SWEET FERN. Comptonia peregrina (1.) Coulter. Synonyms.—Comptonia asplenifolia Gaertn.; Myrica asplenifolia L.; Liquidambar asplenifolia L..; Liquidambar peregrina L. Other common names.—Fern gale, fern bush, meadow fern, shrubby fern, Canada sweet gale, spleenwort bush, sweet bush, sweet ferry. Habitat and range.—Sweet fern is usually found on hillsides, in dry soil, in Canada and the northeastern United States. It is indigenous. Description.—The fragrant odor and the resemblance of the leaves of this plant to those of a fern. have given rise to the common name “sweet fern.”’ It is a shrub with reddish-brown bark, growing from about 1 to 3 feet in height, with slender, erect or spread- ing branches, the leaves hairy when young. The thin narrow leaves are borne on short stalks and are linear oblong or linear lance shaped, about 3 to 6 inches long and from one-fourth to half an inch wide, deeply divided into many lobes, the margins of which are generally en- tire or sparingly toothed. The catkins expand with the leaves. (Fig. 1.) The staminate or male flowers are produced in cylindrical catkins in clusters at the ends of the branches and are about an inch in length, the kidney-shaped scales overlapping. The pistil- late or female flowers are borne in egg-shaped or roundish-oval catkins, the Fig. 1.—Sweet fern (Comptonia peregrina), leaves, male and female eightawl-shaped bractlets catkins. persisting and surround- ing the one-seeded, shining, light-brown nut, giving it a burlike appearance. The whole plant has a spicy, aromatic odor, which is more pronounced when the leaves are bruised. Sweet fern belongs to the bayberry family (Myricacez). Collection, prices, and uses.—The entire plant is used, hut especially the leaves and tops. It has a fragrant, spicy odor and an aromatic, slightly bitter, and astringent taste. The present price of sweet fern is about 3 to 5 cents a pound. It is used for its tonic and astringent properties, principally in a domestic way, as a remedy in diarrheal complaints. 97225°—Bul. 219—11 2 10 AMERICAN MEDICINAL LEAVES AND HERBS. LIVERLEAF. (1) Hepatica hepatica (1.) Karst.; (2) Hepatica acuta (Pursh) Britton. Synonyms.—(1) Hepatica triloba Chaix.; Anemone hepatica L. (2) Hepatica triloba var. acuta Pursh; [Tepatica acutiloba DC. Other common names.—(1) Round-leaved hepatica, common liverleaf, kidney liver- leaf, liverwort (incorrect), noble liverwort, heart liverwort, three-leaved liverwort, liverweed, herb-trinity, golden trefoil, ivy flower, mouse-ears, squirrel cup; (2) heart liverleaf, acute-lobed liverleaf, sharp-lobed liverleaf, sharp-lobed hepatica. Habitat and range.—The common liverleaf is found in woods from Nova Scotia to nortbern Florida and west to Iowa and Missouri, while the heart liverleaf occurs from Quebec to Ontario, south to Georgia (but rare near the coast), and west to Iowa and Minnesota. Description.—The hepat- icas are among the earliest of our spring flowers, blos- soming about March, and frequently before that time. They grow only about 4 to 6 inches in height, with leaves pro- duced from the roots on long soft-hairy stalks and spreading on the ground. The thick and leathery evergreen leaves are kid- ney shaped or roundish and deeply divided into three oval, blunt lobes; the young leaves are pale green and soft hairy, but the older ones become leathery and smooth, expanding when mature to almost 3 inches across; they are dark green above, sometimes with a purplish tinge, and also of a purplish color on the under surface. The flowers, which are about one-half inch in diameter, are borne singly on slender, hairy stalks arising from the root, and vary in color from bluish to purple or white. Immediately beneath the flower are three small, stemless, oval, and blunt leaflets or bracts, which are thickly covered with soft, silky hairs. (Fig. 2.) The heart liverleaf is very similar to the common liverleaf. It grows perhaps a trifle taller and the lobes of the leaf and the small leaflets or bracts immediately under the flower are more sharply pointed. The hepaticas are members of the crowfoot family (Ranunculaceze) and are perennials. The name ‘‘liverwort,” often given to these plants, is incorrect, since it belongs to an entirely different genus. Collection, prices, and uses.—The leaves, which were official in the United States Pharmacopceia from 1830 to 1880, are the parts employed; they should be collected Fic. 2.—Liverleaf{ Hepatica hepatica), flowering plant. 219 PLANTS FURNISHING MEDICINAL LEAVES AND HERBS. Line in April. They lose about three-fourths of their weight in drying. The price at present paid for them is about 4 to 5 cents a pound. Liverleaf is employed for its tonic properties and is said to be useful in affections of the liver. CELANDINE., Chelidonium majus L. Other common names.—Chelidonium, garden celandine, greater celandine, tetter- wort, killwart, wart flower, wartweed, wartwort, felonwort, cockfoot. devil’s-milk, Jacob’s ladder, swallow- wort, wretweed. Habitat and range.—Cel- andine, naturalized from Europe, is found in rich damp soil along fences and roadsides near towns from Maine toOntarioandsouth- ward. It is common from southern Maine to Penn- sylvania. Description.—This plant, which has rather weak, brittle stems arising from a reddish-brown, branch- ing root, is a biennial be- longing to the poppy fam- ily (Papaveracee) and, like other members of this family, contains an acrid juice, which in this species is colored yellow. It is an erect, branched, spar- ingly hairy herb, from about | to 2 feet in height, with thin leaves 4 to 8 inches in length. The leaves, which are lyre shaped in outline, are deeply and variously cleft, the lobes thus formed be- ing oval, blunt, and wavy or round toothed, or rather deeply cut. They have a grayish-green appearance, especially on the lower surface. The small, 4-petaled, sulphur-yellow flowers of the celandine are produced from about April to Septem- ber, followed by smooth, long, pod-shaped capsules crowned with the persistent style and stigma and containing numerous seeds. (Fig. 3.) Collection, prices, and uses.—The entire plant, which was official in the United States Pharmacopeeia for 1890, is used. It should be collected when the herb is in flower. At present it brings about 6 or 8 cents a pound. The fresh plant has an unpleasant, acrid odor when bruised, but in the dried state it is odorless. It has a persistent acrid and somewhat salty taste. Celandine is an old remedy. it has cathartic and diuretic properties, promotes perspiration, and has been used as an expectorant. The juice has been employed externally for warts, corns, and some forms of skin diseases. aS) Fic. 3.—Celandine (Chelidonium majus), leaves, flowers, and seed pods. 12 AMERICAN MEDICINAL LEAVES AND HERBS. WITCH-HAZEL, Hamamelis virginiana L. Pharmacopaial name.—Hamamelidis folia. Other common names.—Snapping hazel, winterbloom, wych-hazel, striped alder, spotted alder, tobacco wood. Habitat and range.—The home of this native shrub is in low damp woods from New Brunswick to Minnesota and south to Florida and Texas. Description.—This shrub, while it may grow to 25 feet in height, is more frequently found reaching a height of only 8 to 15 feet, its crooked stem and long forking branches covered with smoothish brown bark, sometimes with an addition of lichens. A peculiar feature about witch-hazel isits flowering in very late fall or even early winter, when its branches are destitute of leaves, the seed forming but not ripen- ing until the following season. The leaves are rather large, 3 to 5 inches long, thick, and borne on short stalks; they are broadly oval or heart- shaped oval, sometimes pointed and sometimes blunt at the apex, with un- even sides at the base, and wavy margins. The older leaves are smooth, but when The upper surface of the leaves isa light- green or brownish-green color, while the lower surface is pale green and somewhat shining, with prominent veins. The threadlike bright-yellow flowers, which appear very late in autumn, are rather odd looking and consist of a 4-parted corolla with four long, narrow, strap- : shaped petals, which are twisted in vari- ous ways when in full flower. The seed capsule does not mature until the following sea- son, when the beaked and densely hairy seed case bursts open elastically, scattering with great force and toa considerable distance the large, shining-black, hard seeds. (Fig. 4.) This interesting shrub is a member of the witch-hazel family (Hamamelidacez). Collection, prices, and uses.—Witch-hazel leaves are official in the United States Pharmacopeeia. They should be collected in autumn and carefully dried. Formerly the leaves alone were recognized in the United States Pharmacopeia, but now the bark and twigs are also official. The leaves have a faint odor and an astringent, some- what bitter, and aromatic taste. They bring about 2 to 3 cents a pound. The soothing properties of witch-hazel were known among the Indians, and it is still employed for the relief of inflammatory conditions. 219 Fic. 4.—Witch-hazel (Hamamelis virginiana), leaves, flowers, and capsules. young they are covered with downy hairs. PLANTS FURNISHING MEDICINAL LEAVES AND HERBS. Ls : AMERICAN SENNA. Cassia marilandica J,. Synonym.—Senna marilandica Link. Other common names.—Wild senna, locust plant. Habitat and range.—American senna generally frequents wet or swampy soils from New England to North Carolina and westward to Louisiana and Nebraska. Description.—This is a native species, a member of the senna family (Cesalpini- acez), which is closely related to the pea family. It is a perennial herb, its round grooved stems reaching about 4 to 6 feet in height. The leaves, which are borne on long, somewhat bristly hairy stalks, are 6 to 8 inches long and consist of from 12 to 20 leaflets placed opposite to each other on the stem. Each leaflet is oblong or Jance-shaped ob- long, blunt at the top but terminating with a short, stiff point, rounded at the base and from J to 14inches long, the stalks supporting them being rather short; the upper surface is of a pale-green color, while un- derneath it is still lighter in color and covered with a bloom. On the upper surface of the leaf stem, near its base, is a promi- nent club-shaped gland, borne on a stalk. The numerous yellow flowers are borne on slen- der, hairy stems, produced in clusters in the axils of the leaves at the top of the plant and appearing from about August to Septem- ber. The pods are about 3 inches in length, linear, somewhat curved and drooping, slightly hairy at first, flat, and narrowed on the sides between the seeds. They contain numerous small, flat, dark-brown seeds. (Fig. 5.) Collection, prices, and uses.—The leaves, or rather the leaflets, are the parts employed and should be gathered at flowering time, which usually occurs during July and August. They were official in the United States Pharmacopceia from 1820 to 1880. American senna leaves have a very slight odor and a rather disagreeable taste, somewhat like that of the foreign senna. It is used for purposes similar to the well-known senna of commerce imported from abroad, having, like that, cathartic properties. The price at present paid for American senna is about 6 to 8 cents a pound. SD Fic. 5.—American senna (Cassia marilandica), leaves, flowers, and seed pods. 14 AMERICAN MEDICINAL LEAVES AND HERBS, EVENING PRIMROSE. Oenothera biennis L. Synonyms.—Onagra biennis (L.) Scop.; Oenothera muricata L. Other common names.—Common evening primrose, wild evening primrose, field evening primrose, tree primrose, fever plant, night willow-herb, king’s cure-all,! large rampion, scurvish, scabish. Habitat and range.—This is a widely distributed herb, its range extending from Labrador south to Florida and west. to the Rocky Mountains. 1t usually frequents fields and waste places, oc- curring in dry soil. Description.—The even- ing primrose is a coarse an- nual or biennial weed, which has the peculiarity that its flowers do not open until evening, remaining open all night and closing the next morning, but not expandingagain. Itisgen- erally stout and erect in growth, from 1 foot to about 5 feet in height, simple or branched, usually hairy and leafy. The leaves are 1 to 6inchesin length, lance shaped and sharp pointed at the top, with wavy toothed margins narrowing toward the base. With the exception of some of the leaves near the base, most of them are stemless. The spikes of fragrant sulphur- yellow flowers are produced from about June to October and, as already stated and .as indicated by the name ‘‘evening” primrese, they are open late in the evening andduringthenight. They are borne at the end of the Fic. 6.—Evening primrose (Oenothera biennis), leaves, flowers, and stem and are interspersed capsules. with leafy bracts. Each flower has four spreading petals and measures about 1 to 2 inches across. The seed capsules are oblong and hairy, about an inch in length, and narrowed at the top. (Fig. 6.) This plant belongs to the evening primrose family (Onagracez). Collection, prices, and uses.—The entire plant is used. It is collected about flower- ing time, bringing about 5 cents a pound. The herb has a somewhat astringent and mucilaginous taste, but no odor. It has been used for coughs and asthmatic troubles, and an ointment made therefrom has been employed as an application in skin affections. AN) 1A misleading name. PLANTS FURNISHING MEDICINAL LEAVES AND HERBS. 15 YERBA SANTA. Eriodictyon californicum (H. and A.) Greene. Pharmacopeial name.—Eriodictyon. Synonym.—Eriodictyon glutinosum Benth, Other common names.—Mountain balm, consumptive’s weed,! bear’s-weed, gum plant, tarweed. Description.—This evergreen shrub, a member of the waterleaf family (Hydro- phyllacez), reaches a height of from 3 to 4 feet, bearing glutinous leaves. The stem issmooth, butex- udes a gummy substance. The dark-green leaves are from 3 to 4 inchesin length, placed alternately on the stem, oblong or oval lance shaped, leathery, narrow- ing gradually into a short stalk, and with margins generally toothed, except perhaps at the base: the upper surface is smooth, with depressed veins, the prominent veins on the under surface forming a strong network and the spaces between the veins covered with short felty hairs, giving it a white ap- pearance. The leaves are coated with a resinous sub- stance, making them ap- pear asif varnished. The rather showy whitish or pale-blue flowers are borne in clusters at the top of the plant, the tubular, funnel- shaped corolla measuring about half an inch in leneth and having five spreading lobes. (Fig.7.) Theseed ‘capsule is oval, grayish brown, and contains small, reddish-brown, | shriveled seeds. Fic. 7.—Yerba santa ( Eriodictyon californicum), leaves and flowers. Collection, prices, and uses.—The leaves are the parts collected for medicinal use and are official in the United States Pharmacopceia. The price paid for them is about 5 cents a pound. Yerba santa has expectorant properties and is employed for throat and bronchial affections. It is also used as a bitter tonic. The odor is aromatic and the taste balsamic and sweetish. 1 A popular but misleading name. . ES 16 AMERICAN MEDICINAL LEAVES AND HERBS. PIPSISSEWA, Chimaphila umbellata (L.) Nutt. Pharmacopeial name.—Chimaphila. Synonyms.—Pyrola umbellata L.; Chimaphila corymbosa Pursh, Other common names.—Prince’s pine, pyrola, rheumatism weed, bitter wintergreen, ground holly, king’s cure, love-in-winter, noble pine, pine tulip, Habitat and range.—Pipsissewa is a native of this country, growing in dry, shady ie woods, @specially in pine forests, and its range ex- tends from Nova Scotia to & : . British Columbia, south to aA \& Georgia, Mexico, and Cali- fornia. It also occurs in Europe and Asia. Description.—This small perennial herb, a foot or less in height, has a long, run- ning, partly underground stem. It belongs to the heath family (Ericacez) and has shining evergreen leaves of a somewhat leath- ery texture placed ina cir- clearound the stem, usually near the top or scattered along it. They are dark green, broader at the top, with a sharp or blunt apex, narrowing toward the base and with margins sharply toothed; they are from about 1 to 2 inches long and about three-eighths to a little more than half an inch <4 wide at the broadest part. ba Irom about June to August " the pipsissewa may be Fic. 8.—Pipsissewa (B) and spotted wintergreen (A) (Chimaphila found in flower, its pretty umbellata and C. maculata), flowering and fruiting plants. waxy-white or pinkish fra- grant flowers, consisting of five rounded, concave petals, each one with a dark-pink spot at the base, nodding in clusters from the top of the erect stem. The brown capsules contain numerous very small seeds. (Fig. 8.) Collection, prices, and uses —Although the United States Pharmacopceia directs that the leaves be used, the entire plant is frequently employed, as all parts of it are active. Pipsissewa leaves have no odor, but a bitter, astringent taste. They bring about 4 cents a pound. Pipsissewa has slightly tonic, astringent, and diuretic prop- ertics and is sometimes employed in rheumatic and kidney affections. Externally it has been applied to ulcers. ' Another specics.—The leaves of the spotted wintergreen (Chimaphila maculata Pursh) were official in the Pharmacoperia of the United States from 1830 to 1840. These may be distinguished from the leaves of C. wmbellata (pipsissewa) by their olive-green color marked with white along the midrib and veins. They are lance shaped in out- line and are broadest at the base instead of at the top asin C. wmbellata. 91a PLANTS FURNISHING MEDICINAL LEAVES AND HERBS. Laf| MOUNTAIN LAUREL. Kalmia latifolia 1. Other common names.—Broad-leaved laurel, broad-leaved kalmia, American laurel, sheep laurel, rose laurel, spurge laurel, small laurel, wood laurel, kalmia, calico bush, spoonwood, spoon- hunt, ivy bush, big-leaved ivy, wicky, calmoun. Habitat and range.—The mountain laurel is found in sandy or rocky soil in woods from New Bruns- wick south to Ohio, Flor- ida, and Louisiana. Description.—This is an evergreen shrubfromabout 4 to 20 feet in height, with ‘leathery leaves, and when in flower it is one of the most beautiful and showy of our native plants. It has very stiff branches and leathery oval or elliptical leaves borne on stems, mostly alternate, pointed at both ends, with margins entire, smooth and bright green on both sides, and having terminal, clammy- hairy clusters of flowers, which appear from about May to June. The buds are rather oddly shaped and fluted, at first of a deep rose color, expanding Fic. 9.—Mountain laurel ( Kalmia latifolia), \eaves and flowers. into saucer-shaped, more delicately tinted, whitish-pink flowers. Each saucer-shaped flower is provided with 10 pockets holding the anthers of the stamens, but from which these free themselves elastically when the flower is fully expanded. (Fig. 9.) The seed capsule is somewhat globular, the calyx and threadlike style remaining attached until the capsulesopen. Mountain laurel, which belongs to the heath family ( Ericacez), is poisonous to sheep and calves. Collection, prices, and yses.—The leaves, which bring about 3 to 4 cents a pound, are collected in the fall. They are used for their astringent properties. 97225°—Bul. 219—11——3 18 AMERICAN MEDICINAL LEAVES AND HERBS. GRAVEL PLANT. Epigaea repens L. Other common names,—Trailing arbutus, Mayflower, shad-flower, ground laurel, mountain pink, winter pink. Habitat and range.—This shrubby little plant spreads out on the ground in sandy soil, being found especially under evergreen trees from Florida to Michigan and northward. Description.—The gravel plant is one of our early spring flowers, and under its more popular name “trailing ‘arbutus” it is greatly prized on account of its delicate shell-pink, waxy blossoms with their faint yet spicy fragrance. Gravel plant is the name that is generally applied to it in the drug trade. It spreads on the ground with stems 6 inches or more in length and has rust-colored hairy twigs bearing ever- green leaves. The leaves are green aboveand below, thick and leathery, oval or roundish, sometimes with the top pointed, blunt, or having a short stiff point and a rounded or heart- shaped base. The mar- gins are unbroken and the upper surface is smooth, while the lower surface is somewhat hairy. The leaves measure from 1 to 3 inches in length and are about half as wide, the hairy stalkssup- porting them ranging from one-fourth of an inch to 2 inches in length. Early in the year, from about March to May, the flower clusters appear. These are borne in the axils of the leaves and at the ends of the branches and consist of several waxy, pinkish-white, fragrant flowers with saucer-shaped, 5-lobed corolla, the throat of the corolla tube being very densely hairy within. (Fig.10.) The seed capsule is some- what roundish, flattened, five celled, and contains numerous seeds. The gravel plant belongs to the heath family (Ericacez) and is a perennial. Collection, prices, and uses.—The leaves are collected at flowering time and are worth about 3 or 4 centsa pound. They have a bitter, astringent taste and are said to possess astringent and diuretic properties. 219 Fic. 10.—Gravel plant ( Epigaea repens), leaves and flowers. PLANTS FURNISHING MEDICINAL LEAVES AND HERBS. 19 WINTERGREEN. Gaultheria procumbens 1. Other common names.—Gaultheria, spring wintergreen, creeping wintergreen, aromatic wintergreen, spicy wintergreen, checkerberry, teaberry, partridge berry, grouseberry, spiceberry, chickenberry, deerberry, groundberry, hillberry, ivyberry, boxberry, redberry tea, Ca- nadian tea, mountain tea, ivory plum, chinks, drunk- ards, red pollom, rapper dandies, wax cluster. Habitat and range.—This small native perennial fre- quents sandy soils in cool damp woods, occurring es- pecially under evergreen trees in Canada and the northeastern United States. Description.—Winter- ereen is anaromatic, ever- green plant withan under- ground or creeping stem producing erect branches not more than 6 inches in height, the lower part of which is smooth and naked, while near the ends are borne the crowded clusters of evergreen leaves. These are alter- nate, shining dark green above, lighter colored underneath, spicy, thick Fic. 11.—Wintergreen (Gaultheria procumbens), flowering and fruit- and leathery, oval and HSU narrowing toward the base, | to 14 inches in length, and of varying width. From about June to September the solitary, somewhat urn-shaped and five-toothed white and waxy flowers appear, borne on recurved stems in the axils of the leaves. (Fig. 11.) These are followed by globular, somewhat flattened berries, which ripen in autumn and remain on the plant, sometimes until spring. They are bright red, five celled, mealy, and spicy. All parts of the plant, which belongs to the heath family (Ericacez), are aromatic. Collection, prices, and uses.—The leaves of wintergreen, or gaultheria, were at one time official in the United States Pharmacopeeia, but now only the oil of wintergreen, distilled from the leaves, is so regarded. The leaves should be collected in autumn. Sometimes the entire plant is pulled up and, after drying, the leaves readily shake off. The price paid to collectors ranges from about 3 to 4 cents a pound. Wintergreen has stimulant, antiseptic, and diuretic properties. Its chief use, however, seems to be as a flavoring agent. 219 20 AMERICAN MEDICINAL LEAVES AND HERBS. BEARBERRY. Arctostaphylos uva-ursi (.) Spreng. Pharmacopeial name.—U va ursi. Other common names.—Red bearberry, bear's-grape, bear's bilberry, bear’s whortle- berry, foxberry, upland cranberry, mountain cranberry, crowberry, mealberry, rock- berry, mountain box, kinnikinnic, killikinic, universe vine, brawlins, burren myrtle, creashak, sagachomi, rap- per dandies (fruit). Habitat and rang e.— Bearberry is a native of this country, growing in dry sandy or rocky soil from the Middle Atlantic States north to Labrador and westward to California and Alaska. Description.—The bear- berry is a low, much- branched shrub trailing over the ground and hay- ing leathery, evergreen leaves. It isa member of the heath family (Erica- cee) and produces its pretty waxy flowers about May. The numerous crowded leaves are thick and leathery, evergreen, about one-half to Ll inch in length, blunt and widest at the top and narrowing at the base, with a net- work of fine veins, smooth, and with margins entire. The flowers are few, borne in short drooping clusters at the ends of the branches, and are ovoid or somewhat bell shaped in form, four or five lobed, white with a pinkish tinge. They are followed by smooth, red, globular fruits, with an insipid, rather dry pulp, containing five nutlets. (Fig. 12.) Collection, prices, and uses.—Bearberry or uva ursi leaves, official in the United States Pharmacopeeia. are collected in autumn. Collectors receive from about 2 to 4 cents a pound for them. Bearberry leaves have a bitter, astringent taste and a faint odor. They act on the kidneys and bladder and have astringent and tonic properties. Another species.—The leaves of manzanita (Arctostaphylos glauca Lindl.), a shrub- like tree, 9 to 25 feet high, have properties similar to uva ursi and are also used in medicine for similar purposes. They are of a leathery texture, pale green, ovate oblong in shape, with unbroken margins, and about 2 inches in length. Manzanita crows in California, in dry rocky districts on the western slopes of the Sierras. 219 Fic. 12.—Bearberry (Arctostaphylos uva-ursi), leaves and fruits. PLANTS FURNISHING MEDICINAL LEAVES AND HERBS. 21 BUCK BEAN. Menyanthes trifoliata L. Other common names.—Bog bean, bog myrtle, bog hop, bog nut, brook bean, bean trefoil, marsh trefoil, water trefoil, bitter trefoil, water shamrock, marsh clover, moonflower, bitterworm. Habitat and range.—The buck bean is a marsh herb occurring in North America as far south as Pennsylvania, Minnesota, and California. It is also native in Europe. Description.—This _per- ennial herb arises from a long, black, creeping, scaly rootstock, the leaves be- ing produced from the end of the same on _ erect sheathing stems measuring about 2 to 10 inches in height. The leaves con- sist of three oblong-oval or broadly oval leaflets 13 to 3 inches long, somewhat fleshy and smooth, blunt at the top, with margins entire and narrowed to- ward the base; the upper surface is pale green and the lower surface some- what glossy, with the thick midrib lightin color. The flower cluster is produced from May to July ona long, thick, naked stalk arising from the rootstock It bears from 10 to 20 flowers, each with a funnel-shaped tube terminating in five segments which are pink- ish purple or whitish on the outside and whitish and thickly bearded with white hairs within. (Fig. 13.) The capsules which follow are ovate, blunt at the top, smooth and light brown, and contain numerous smooth and shining seeds. Buck bean is a perennial belonging to the buck-bean family (Menyanthacez). Collection, prices, and uses.—The leaves are generally collected in spring. They lose more than three-fourths of their weight in drying. The price paid per pound is about 6 to 8 cents. Buck-bean leaves have a very bitter taste, but no odor. Large doses are said to have cathartic and sometimes emetic action, but the principal use of buck-bean leaves is as a bitter tonic. They have been employed in dyspepsia, fevers, rheumatic and skin affections, and also as a remedy against worms. The rootstock is also sometimes employed medicinally and was recognized in the United States Pharmacopeeia from 1830 to 1840. 219 Fic. 13.—Buck bean ( Menyanthes trifoliata), flowering plant. 22 AMERICAN MEDICINAL LEAVES AND HERBS, SKULLCAP. Scutellaria lateriflora L. Pharmacopeial name.—Scutellaria. Other common names.—American skullcap, blue skullcap, mad-dog skullcap, side- flowering skullcap, madweed, hoodwort, blue pimpernel, hooded willow-herb. Habitat and range.—This species is native in damp places along banks of streams from Canada southward to Florida, New Mexico, and Washington. Description.—The lip- shaped flowers and squar- ish stems of the skullcap indicate that it isa member of the mint family (Men- thacex). It isa perennial of slender, erect habit, its square, leafy, branching stem ranging from 8 inches to 2 feet in height, smooth, or sometimes hairy at the top. Theleavesareplaced opposite to each other on the stem on slender stalks and are about | to 3 inches in length and about one- third as wide, thin in tex- ture, oblong or lance shaped, with margins coarsely toothed. They gradually become smaller toward the top, and sometimes those at the very top have the margins unbroken. The flowers are borne in narrow, spikelike, one-sided clus- ters, generally in the axils Fic. 14.—Skulleap (Scutellaria laterifiora), flowering branch, showing of the leaves, but frequent- also seed capsules. ly also at the top, and are interspersed with leafy bracts. They appear from about July to September and are blue, shading off to whitish. The tubular, 2-lipped flowers are about a quarter of an inch in length, and the calyx, or outer green covering of the flower, is also two lipped, the upper lip shaped like a helmet and closing in fruit. (Fig. 14.) Collection, prices, and uses.—The dried plant is at present official in the United States Pharmacopeeia. The entire plant is collected when in flower and should be carefully dried in the shade. The price ranges from about 3 to 4 cents a pound. Very frequently collectors will gather some other species in place of the official plant, most of those thus wrongly finding their way into the market being generally of stouter growth, with broader leaves and much larger flowers. This plant was once considered valuable for the prevention of hydrophobia, whence the names ‘‘mad-dog skullcap” and ‘‘madweed,”’ but it is now known to be useless for that purpose. It is used principally as a tonic and to a limited extent for allaying nervous irritation of various kinds. 219 PLANTS FURNISHING MEDICINAL LEAVES AND HERBS. De HOREHOUND. Marrubium vulgare L. Pharmacopetal name.—Marrubium. Other common names.—HHoundsbene, marvel, marrube. Habitat and range.—Horehound grows in dry sandy or stony soil in waste places, along roadsides and near dwellings, in fields, and pastures. It is found from Maine to South Carolina, Texas, and westward to California and Oregon. It is very abundant in pastures in Oregon and California, and especially in southern California, where it is a very trouble- some weed, covering vast areas and in such dense masses as to crowd out all other vegetation. It has been naturalized from Europe. Description.—The entire plant is thickly covered with hairs, which give it a whitish, woolly appearance. It is a bushy, branching herb, having a pleasant aromatic odor, and is about 1 to 3 feet high, with many woolly stems rounded below and four angled above, with opposite, oval or round- ish, wrinkled, strongly veined, and very hoary leaves. The leaves are about 1 to 2 inches in length, placed opposite each other on the stem, oval or nearly round, somewhat blunt at the apex, and narrowed or somewhat heart shaped at the base, the margins round toothed; the upper surface is wrinkled and somewhat hairy, while the lower surface is very hoary and prominently veined. The lip- shaped flowers, which appear from June to September, show that it isa member of the mint family (Mentha- cee). These are borne in dense woolly clusters in the axils of the leaves and are whitish, two lipped, the upper lip two lobed, the lower three lobed. The hooked calyx teeth of the mature flower heads cling to the wool of sheep, resulting in the scattering of the seeds. (Fig. 15.) Collection, prices, and uses.—The leaves and tops are the parts used in medicine and are official in the United States Pharmacopeeia. These are gathered just before the plant is in flower, the coarse stalks being rejected. They should be carefully dried in the shade. The odor is pleasant, rather aromatic, but diminishes in drying. The taste is bitter and persistent. Horehound at present brings about 1} to 2 cents a pound. It is well known as a domestic remedy for colds and is also used in dyspepsia and for expelling worms. 219 Fig. 15.—Horehound (Marrubium vulgare), leaves, flowers, and seed clusters. 24 AMERICAN MEDICINAL LEAVES AND HERBS. CATNIP. Nepeta cataria L. Other common names.—Cataria, catmint, catwort, catrup, field mint. Habitat and range.—Catnip, a common weed naturalized from Europe, occurs in rather dry soil in waste places and cultivated land from Canada to Minnesota and south to Virginia and Arkansas. Description.—The fine white hairs on the stems of this plant give it a somewhat whitish appear- ance. Catnip reaches about 2 to 3 feet in height, with erect, square, and branched stems. It isa perennial belonging to the mint family (Menthacez). The opposite leaves are heart shaped or oblong, with a pointed apex, the upper surface green, the lower grayish green with fine white hairs, the mar- gins finely scalloped and 1 to 2} inches in length. About June to Septem- ber the many-flowered, rather thick spikes are produced at the ends of the stem and branches. The whitish flowers, dot- ted with purple, are two lipped, the upper lip notched or two cleft, the lower one with three lobes, the middle lobe broadest and sometimes two cleft. (Fig. 16). Collection, prices, and uses.—The leaves and flowering tops, which have a strong odor and a bitter taste, are collected when the plant is in flower and are carefully dried. The coarser stems and branches should be rejected. Catnip was official in the United States Pharmacopcria from 1840 to 1880. The price ranges from 3 to 5 cents a pound. Catnip is used as a mild stimulant and tonic and as an emmenagogue. It also hasa quieting effect on the nervous system. Fig 16.—Catnip (Nepeta cataria), leaves and flowers. 219 PLANTS FURNISHING MEDICINAL LEAVES AND HERBS. 25 MOTHERWORT. Leonurus cardiaca J.. Synonym.—Cardiaca vulgaris Moench. Other common names.—Throwwort, cowthwort, lion’s-tail, lion’s-ear. Habitat and range.—Motherwort, naturalized from Europe and a native also of Asia, is found about dwellings and in waste places, its range in this country ex- tending from Nova Scotia to North Carolina, Minne- sota, and Nebraska. Description.—The rather stout, erect, 4- angled stem of this peren- nial herb attains a height of from 2 to 5 feet, is spar- ingly hairy, and has up- right branches. The rough, dark-green leaves are borne on long stems, the lower ones rounded, about 2 to 4 inches wide and three to five lobed, the lobes pointed, toothed, or variously cut, the upper narrower ones three cleft with lance-shaped lobes. Motherwort flowers in summer, the pale-purple or pinkish lip-shaped blossoms produced in the axils of the leaves being arranged in dense circles around the stem; the up- per lip is densely covered Fic. 17.—Motherwort (Leonurus cardiaca), leaves, flowers, and seed with white, woolly hairs — on the outside and the lower lip is three lobed and mottled. (Fig.17.) Motherwort belongs to the mint family (Menthacez). Collection, prices, and uses.—The leaves and flowering tops are collected during the flowering season. They have an aromatic odor and a very bitter taste. At present they bring about 3 to 5 cents a pound. Motherwort has stimulant, slightly tonic properties and is used also to promote perspiration. 97225°—Bul. 219—11—_-4 26 AMERICAN MEDICINAL LEAVES AND HERBS. PENNYROYAL. Hedeoma pulegioides (L.) Pers. Pharmacopeial name.—Hedeoma. Other common names.—American pennyroyal, mock pennyroyal, squaw mint, tick- weed, stinking balm, mos- quito plant. Habitatandrange.—Pen- nyroyal is found in dry soil from Nova Scotia and Quebec to Dakota and southward. Description.—This very strongly aromatic annual of the mint family (Men- thacez) is of rather insig- nificant appearance, being a low-growing plant, about 6 inches to a foot or so in height, with a slender, erect, much-branched and somewhat hairy stem. The opposite leaves are small, scarcely exceeding three-fourths of an inch in length and becoming smaller toward the top of the plant. They are borne on short stems and are ob- long ovate in shape, thin, blunt at the apex, nar- rowed at the base, and with margins sparingly toothed. The branchlets are fouran- gled and somewhat hairy, and the loose flower clus- ters, appearing from July to September in the axils of the leaves, consist of a few pale-bluish flowers with 2- lipped corolla; the erect upper one entire or slightly notched or two lobed, while the lower spreading lip is three cleft. (Fig. 18.) Collection, prices, and uses.—The leaves and flowering tops are official in the United States Pharmacopeeia, as is also the oil of pennyroyal distilled from them. They should be collected while in flower. The price paid to collectors ranges from about 1} to 24 cents a pound. ; Pennyroyal has a strong mintlike odor and pungent taste and is used as an aromatic stimulant, carminative, and emmenagogue. The odor is very repulsive to insects, and pennyroyal is therefore much used for keeping away mosquitoes and other trouble- some insects. 219 Fic. 18.—Pennyroyal ( Hedeoma pulegioides), leaves and flowers. PLANTS FURNISHING MEDICINAL LEAVES AND HERBS. OT BUGLEWEED. Lycopus virginicus Li. Other common names.—Buglewort, sweet bugleweed, American water horehound, carpenter's herb, green archangel, gypsyweed, Paul’s betony, wood betony, wolf foot, purple archangel, water bugle, gypsywort, gypsy herb, Virginia horehound. Habitat and range.— Bugleweed is a native herb frequenting wet, shady places from Canada to Florida, Missouri, and Nebraska. Descriplion.—This per- ennial herb of the mint family (Menthaceze) has long, threadlike runners and a bluntly 4-angled, smooth, slender, erect or ascending stem from 6 inches to 2 feet in height. The leaves are dark green or of a purplish tinge, about 2 inches in length, long pointed at the apex and narrowed toward the base, the upper portion of the margin being toothed. The small, tubular, bell- shaped, 4-lobed flowers are purplish and are pro- duced from about July to September. They are borne in dense clusters in the axils of the leavesand are followed by 3-sided nutlets. (Fig. 19.) Fia. 19.—Bugleweed (Lycopus virginicus), leaves and flowers. Collection, prices, and uses.—The entire herb, which was official from 1830 to 1580, should be gathered during the flowering period. It brings about 3 to 4 cents a pound, The plant has arather pleasant, mintlike odor, but the taste is bitter and disagreeable. It has sedative, tonic, and astringent properties. 219 28 AMERICAN MEDICINAL LEAVES AND HERBS. PEPPERMINT, Mentha piperita Li. Pharmacopeial name.—Mentha piperita. Other common names.—American mint, brandy mint, lamb mint, lammint, State mint (in New York). Habitat and range.—Peppermint is naturalized from Europe and is found in damp places from Nova Scotia to Minnesota and south to Florida and Tennessee. It is largely cultivated, princi- pally in Michigan and New York, where the dis- tillation of the plants for the oil is carried on com- mercially on a very ex- tensive scale, and also in parts of Indiana, Lowa, and Wisconsin. Description.—P e p per- mint propagates by means of its long, running roots, from which are produced smooth, square stems, from | to 3 feet in height, erect and branching. The dark-green leaves are borne on stalks and are lance shaped, 1 to 2inches . in length and about half as wide, pointed at the apex and rounded or nar- rowed at the base, with margins sharply ‘toothed; they are smooth on both sides, or sometimes the veins on the lower surface are hairy. This aromatic perennial of the mint family (Men- thacez) is in flower from July to September, the small purplish blossoms Fig. 20.—Peppermint (Mentha piperiia), leaves and flowers. havinga tubular, 5-toothed calyx and a 4-lobed corolla. They are placed in circles around the stem, forming thick, blunt, terminal spikes. (Fig. 20.) Collection, prices, and uses.—The dried leaves and flowering tops are the parts di- rected to be used by the United States Pharmacopceia. These must be collected as soon as the flowers begin to open and should be carefully dried in the shade. Dried peppermint leaves and tops bring about 34 to 44 cents a pound. The pungent odor of peppermint is familiar, as is likewise the agreeable taste, burn- ing at first and followed by a feeling of coolness in the mouth. It is a well-known remedy for stomach and intestinal troubles. 219 PLANTS FURNISHING MEDICINAL LEAVES AND HERBS. 29 The oil, which is obtained by distillation with water from the fresh or partially dried leaves and flowering tops, is also official in the United States Pharmacopeeia. While a less acreage was devoted to peppermint during 1910, conditions were favorable to its growth, and the crop is estimated to have amounted to about 200,000 pounds. The wholesale quotations for peppermint oil in the spring of 1911 ranged from $2.85 to $2.95 a pound. SPEARMINT. Mentha spicata L. Pharmacopeial name.— Mentha viridis. Synonym.— Mentha viri- dis L. Other common names.— Mint, brown mint, garden mint, lamb mint, mackerel mint, Our Lady’s mint, sage of Bethlehem. Habitat andrange.—Like peppermint, the spear- mint has also been natu- ralized from Europe and may be found in moist fields and waste places from Nova Scotia to Utah and south to Florida. It is also cultivated to some extent for the distillation of the oil and is a familiar plant in gardens for do- mestic use, Description.—Spearmint very much resembles pep- permint. It does not grow perhaps quite so tall, the lance-shaped leaves are gener- ally stemless or at least with very short stems, and the flowering spikes are narrow and pointed instead of thick and blunt. (Fig. 21.) The flowering period is the same as for peppermint—from July to September. Collection, prices, and uses.—The dried leaves and flowering tops are official in the United States Pharmacopceia and should be collected before the flowers are fully de- veloped. The price at present is about 3} cents a pound. Spearmint is used for similar purposes as peppermint, although its action is milder. The odor and taste closely resemble those of peppermint, but a difference may be detected, the flavor of spearmint being by some regarded as more agreeable. Oil of spearmint is also official in the United States Pharmacopoeia. It is obtained from the fresh or partially dried leaves and flowering tops. 219 Fic. 21.—Spearmint (Mentha spicata), leaves, flowers, and running rootstock. 30 AMERICAN MEDICINAL LEAVES AND HERBS. JIMSON WEED. Datura stramonium L. Pharmacopeial name,—Stramonium. Other common names.—Jamestown weed (from which the name “‘jimson weed ”’ is de- rived), Jamestown lily, thorn apple, devil’sapple, mad-apple, apple of Peru, stinkweed, stinkwort, devil’s-trum- pet, fireweed, dewtry. Habitat andrange.—This is a very common weed in fields and waste places almost everywhere in the United States except in the North and West. It is widely scattered in nearly all warm countries. Description.—J imson weed is an ill-scented, poisonous annual belong-. ing to the nightshade fam- ily(Solanacex). Itsstout, yellowish-green stems are about 2 to 5 feet high, much forked, and leafy with large, thin, wavy- toothed leaves. The leaves are from 3 to 8 inches long, thin, smooth, pointed at the top and usually narrowed at the base, somewhat lobed or irregularly toothed and waved, veiny, the upper surface dark green, while the lower surface isa light- ergreen. The flowersare large (about 3 inches in length), white, funnel shaped, rather showy, and with a pronounced odor. Jimson weed is in flower from about May to September, and the seed pods which follow are dry, oval, prickly cap- sules, about as large as a horse-chestnut, which upon ripening burst open into four valves containing numerous black, wrinkled, kidney-shaped seeds, which are Fic. 22.Jimson weed (Datura stramonium), leaves, flowers, and capsules. poisonous. (Fig. 22.) Collection, prices, and uses.—The leaves of the jimson weed, yielding, when assayed by the United States Pharmacopeeia process, not less than 0.35 per cent of its alkaloids, are official under the name “Stramonium.’’ They are collected at the time jimson weed is in flower, the entire plant being cut or pulled up and the leaves stripped and carefully dried in the shade. They have an unpleasant, narcotic odor and a bitter, nauseous taste. Drying diminishes the disagreeable odor. The collector may receive from 2 to 5 cents a pound for the leaves. The leaves, which are poisonous, cause dilation of the pupil of the eye and also have narcotic, antispasmodic, anodyne, and diuretic properties. In asthma they are fre- quently employed in the form of cigarettes, which are smoked, or the fumes are inhaled. The seeds are also used in medicine. mg PLANTS FURNISHING MEDICINAL LEAVES AND HERBS. 31 BALMONY. Chelone glabra L. Other common names.—Turtlehead, turtle bloom, fishmouth, codhead, salt-rheum weed, snake-head, bitter herb, shell flower. Habitat and range.—This native perennial grows in swamps and along streams from Newfoundland to Mani- toba and south to Florida and Kansas. Description.—Balmony is a slender, erect herb, with a 4-angled stem 1 to 3 feet in height, occasion- ally branched. Theshort- stemmed leaves, which are from 3 to 6 inches in length, are narrowly lance shaped to broadly lance shaped, the lower ones sometimes broadly oval, narrowing toward the base and with margins fur- nished with sharp, close- lyingteeth. Inlatesum- mer or early fall theshowy clusters of whitish or pink- ish flowers are produced. Each flower is about an inch in length, with a tubular, inflated corolla, with the mouth slightly open and resembling the head of a turtle or snake; its broad arched upper lip is keeled in the centerand notched at the apex, while the lower lip is three lobed, the smallest lobe Fic. 23.—Balmony (Chelone glabra). leaves and flowers. in the center, and the throat bearded with woolly hairs. (Fig. 23.) The seed capsule is oval, about half an inch in length, and contains numerous small seeds. Collection, prices, and uses.—The herb (especially the leaves), which brings from 3 to 4 cents a pound, should be collected during the flowering period. Balmony has a very bitter taste, but no odor, and is used as a tonic, for its cathartic properties, and for expelling worms. 219 32 AMERICAN MEDICINAL LEAVES AND HERBS. COMMON SPEEDWELL. Veronica officinalis L. Other common names.—Paul’s betony, ground-hele, fluellin, upland speedwell. Habitat and range.—This little herb frequents dry fields and woods from Nova Scotia to Michigan and south to North Carolina and Tennessee. It also occurs in Europe and Asia. Description.—The common speedwell creeps over the ground by means of rather woody stems rooting at the joints and sends up branches frém 3 to 10 inches in height. It is hairy allover. Theleaves are opposite to each other on thestem, on short stalks, grayish green and soft hairy, oblong or oval in shape, and about one-half toan inch in length; they are blunt at the apex, with margins saw toothed and narrowing into the stalks. From about May to July the elongated, narrow, spikelike flower clusters are produced from the leaf axils, crowded with small, pale-blue flowers. (Fig. 24.) The capsule is obo- vate, triangular, and com- pressed, and contains numerous flat seeds. The speedwell is a perennial belonging to the figwort family (Scrophulariacez). Collection, prices, and uses.—The leaves and flowering tops, which bring Fic. 24.—Common speedwell (Veronica officinalis), leaves and flowers. about 3 to5centsa pound, should be collected about May or June. When fresh they have a faint, agreeable odor, which is lacking when dry. The taste is bitter and aromatic and somewhat astringent. ; Speedwell has been used for asthmatic troubles and coughs and also for its alterative, tonic, and diuretic properties. FOXGLOVE. Digitalis purpurea L. Pharmacopeial name.—Digitalis. Other common names.—Purple foxglove, thimbles, fairy cap, fairy thimbles, fairy fingers, fairy bells, dog’s-finger, finger flower, lady’s-glove, lady’s-finger, lady’s- thimble, popdock, flap dock, flop dock, lion’s-mouth, rabbit’s-flower, cottagers, throatwort, Scotch mercury. 219 PLANTS FURNISHING MEDICINAL LEAVES AND HERBS. 33 Habitat and range.—Originally introduced into this country from Europe as an orna- mental garden plant, foxglove may now be found wild in a few localities in parts of Oregon, Washington, and West Virginia, having escaped from cultivation and assumed the character ofa weed. It occurs along roads and fence rows, in small cleared places, and on the borders of timber land. Description.—Foxglove, a biennial or perennial belonging to the figwort family (Scrophulariacez),during the first year of its growth produces only a dense rosette of leaves, but in the second season the downy and leafy flower- ing stalk, reaching a height of 3 to 4 feet, ap- pears. The basal leaves are rather large, with long stalks, while the upper ones gradually become smaller and are borne on shorter leafstalks. The ovate or oval leaves, 4 to 12 inches long and about half as wide, the upper surface of which is dull green and wrinkled, are narrowed at the base into long winged stalks; the lower surface of the leaves shows a thick network of prominent veins and is grayish, with soft, short hairs. The apex is blunt or pointed and the mar- gins are round toothed. When foxglove is in flower, about June, it isa most handsome plant, the long terminal clusters (about 14 inches in length) of numerous tubular, bell-shaped flowers making a very showy appearance. The individual flowers are about 2 inches long and vary in color from whitish through lavender and purple; the inside of the lower lobe is white, with crimson spots and furnished with long, soft, white hairs. (Fig.25.) The capsule is ovoid, two celled, and many seeded. Collection, prices, and uses.—The leaves, which are official in the United States Pharmacopeeia, are collected from plants of the second year’s growth just about the time that they are coming into flower. They should be very carefully dried in the shade soon after collection and as rapidly as possible, preserving them in dark, air- tight receptacles. The leaves soon lose their medicinal properties if not properly dried or if exposed to light and moisture. Foxglove brings about 6 to 8 cents a pound. At present most of the foxglove or digitalis used comes to this country from Europe, where the plant grows wild and is also cultivated. Foxglove has a faint, rather peculiar odor and a very bitter, nauseous taste. Prepa- rations made from it are of great value in affections of the heart, but they are poisonous and should be used only on the advice ofa physician. 219 Fic. 25.—Foxglove (Digitalis purpurea), leaves and flowers. 34 AMERICAN MEDICINAL LEAVES AND HERBS. SQUAW VINE. Mitchella repens L. Other common names.—Checkerberry, partridgeberry, deerberry, hive vine, squaw- berry, twinberry, chickenberry, cowberry, boxberry, foxberry, partridge vine, winter clover, wild running box, oneberry, pigeonberry, snakeberry, two-eyed ber- ry, squaw-plum. Habitat and range.—The squaw vine is common in woods from Nova Scotia to Minnesota and south to Florida and Arkansas, where it is generally found creeping about the bases of trees. Description.—This slen- der, creeping or trailing evergreen herb, a member of the madder family (Rubiacez), has stems 6 to 12 inches long, rooting at the joints, and roundish- oval, rather thick, shining, dark-green opposite leaves about half an inch in length, which are blunt at the apex and rounded or somewhat heart shaped at the base, with margins entire. Sometimes the leaves show whitish veins. The plant flowers from about April to June, pro- ducing fragrant whitish, sometimes pale-purplish, funnel-shaped and 4-lobed flowers, two borne to- gether on a stalk and having the ovaries (seed-bearing portion) united, resulting in a double, berrylike fruit. These fruits are red and contain eight small, bony nutlets. (Fig. 26.) They remain on the vine through the winter and are edible, though practically tasteless. Collection, prices, and uses.—The leaves and stems (herb) are collected at almost any time of the year and range in price from about 33 to 4centsa pound. The leaves have no odor and are somewhat astringent and bitter. Squaw vine has tonic, astringent, and diuretic properties. 219 Fic. 26.—Squaw vine (Mitchella repens), leaves and fruits. PLANTS FURNISHING MEDICINAL LEAVES AND HERBS. 35 LOBELIA. Lobelia inflata L. Pharmacopeial name.—Lobelia. Other common names.—Indian tobacco, wild tobacco, asthma weed, gagroot, vomit- wort, puke weed, emetic herb, bladder pod, low belia, eyebright. Habitat and range.—Lobelia may be found in sunny situations in open woodlands, old fields and pastures, and along roadsides nearly everywhere in the United States, but especially east of the Mississippi River. Description.—This pois- onous plant, an annual belonging to the bell flower family (Campanulaceze), contains an acrid, milky juice. Itssimplestem has but few short branches and is smooth above, while the lower part is rough hairy. The leaves are placed alternately along the stem, those on the upper portion small and stemless and the lower leaves larger and borne on stalks. They are pale green and thin in texture, from 1 to about 2 inches in length, oblong or oval, blunt at the apex, the margins irregularly saw toothed, and both upper and lower surfaces fur- nished with short hairs. Lobelia may be found in flower from summer until frost, but its pale- Fic. 27.—Lobelia (Lobelia inflata), leaves, flowers, and inflated capsules. blue flowers, while very numerous, are very small and inconspicuous. They are borne on very short stems in the axils of the upper leaves. The lower lip of each flower has three lobes and the upper one two segments, from the center of which the tube is cleft to the base. The inflated capsules are nearly round, marked with parallel grooves, and contain very numerous extremely minute dark-brown seeds. (Fig. 27.) Collection, prices, and uses.—The Pharmacopeceia directs that the leaves and tops be collected after some of the capsules have become inflated. Not too much of the stemmy portion should be included. The leaves and tops should be dried in the shade and when dry kept in covered receptacles. The price paid for the dried leaves and tops is about 3 cents a pound. Lobelia has expectorant properties, acts upon the nervous system and bowels, causes vomiting, and is poisonous. The seed of lobelia is also employed in medicine. 219 36 AMERICAN MEDICINAL LEAVES AND HERBS. BONESET. Eupatorium perfoliatum L. Pharmacopeial name.—Eupatorium. Synonym.—Eupatorium connatum Michx. Other common names.—Thoroughwort, thorough-stem, thoroughwax, wood boneset, teasel, agueweed, feverwort, sweating plant, crosswort, vegetable antimony, Indian sage, wild sage, tearal, wild isaac, Habitat and range.— Boneset is a common weed in low, wet ground, along streams, and on the edges of swamps and in thickets from Canada to Florida and west to Texas and Ne- braska. Deseri ption.—This plant is easily recognized by the peculiar arrangement of the leaves, which are opposite to each other, but joined together at the base, which makes it appear as though they were one, with the stem passing through the center. It is a perennial plant belonging to the aster family (Asteraceze), and is erect, growing rather tall, . from 1 to 5 feet in height. The stout stems are rough hairy,and the leaves, united at the base, are rough, very prominently veined, wrin- kled, dark green above, lighter green and downy beneath, lance shaped, tapering to a point, and with bluntly toothed margins. The crowded, flat-topped clusters of flowers are produced from about July to September and consist of numerous white tubular flowers united in dense heads. (Fig. 28.) Collection, prices, and uses.—The leaves and flowering tops, official in the United States Pharmacopeeia, are collected when the plants are in flower, stripped from the stalk, and carefully dried. They lose considerable of their weight in drying. The price per pound for boneset is about 2 cents. Boneset leaves and tops have a bitter, astringent, taste and a slightly aromatic odor. They form an old and popular remedy in the treatment of fever and ague, as implied by some of the common names given to the plant. Boneset is also employed in ‘colds, dyspepsia, jaundice, and as a tonic. In large doses it acts as an emetic and cathartic. 219 Fic. 28.—Boneset (Eupatorium perfoliatum), leaves and flowers. PLANTS FURNISHING MEDICINAL LEAVES AND HERBS. oF GUM PLANT. (1) Grindelia robusta Nutt.; (2) Grindelia squerrosa (Pursh) Dunal. Pharmacopeial name.—Grindelia. Other common names.—(2) Broad-leaved gum plant, scaly grindelia. Habitat and range.—The gum plant (Grindelia robusta) occurs in the States west of the Rocky Mountains, while the broad-leaved gum plant (G. squarrosa) is more widely distributed, being of common occurrence on the plains and prairies from the Saskatchewan to Minnesota, south to Texas and Mexico, and westward to California. Description.—The name “‘oum plant” is applied especially to Grindelia robusta on account of the fact that the entire plant is covered with a resinous su bs tance, givingita gummy, varnishedappear- ance. It is an erect per- ennial herb belonging to the aster family (Aster- acez) and has a round smooth stem, about 1} feet inheight. The leaves are pale green, leathery in texture and rather rigid, coated with resin and showing numcrous trans- lucent dots, and are about aninchinlength. In out- line they are oblong spat- ulate—that is, having a broad, rounded top gradu- ally narrowing toward the base—clasping the stem and with margins some- what saw toothed. The plant branches freely near the top, each branch some- what reddish and termi- nating in a large yellow flower. The yellow flowers are about three-fourths of an inch in diameter, broader than long, and are borne singly at the ends of the branches. Immediately beneath the flower is a set of numerous, thick, overlapping scales (the involucre), the tips of which are rolled forward, the whole heavily coated with resin. 219 Fig. 29.—Sealy grindelia (Grindelia squarrosa), leaves and flowers. 38 AMERICAN MEDICINAL LEAVES AND HERBS. The broad-leaved gum plant (Grindelia squarrosa) is very similar to G. robusta, except that it is smaller and less gummy in appearance. It is more sparingly branched near the top and the branches seem more reddish. The leaves are also clasping, but they are longer, about 2 inches in length, and broader, thinner in texture and not rigid, and more prominently toothed. The smaller flower heads are generally longer than broad and have narrower involucral scales, the recurved tips of which are longer and more slender. (Fig. 29.) Collection, prices, and uses.—The leaves and flowering tops of beth species of Grin- delia are official in the United States Pharmacopeeia, and should be collected about the time that the flowers have come into full bloom, The price ranges from about 5 to 10 cents a pound. While both spe- cies are official, the leaves and tops of Grindelia squar- rosa, being more prevalent, are generally used. The odor of grindelia is balsamic and the taste resinous, sharply aromatic, and slightly bitter. The drug is sometimes used in asthmatic and similar af- fections, as a stomachic, tonic, and externally in cases of poisoning by poison ivy. CANADA FLEABANE. Leptilon canadense (L.) Britton. Synonym.—Erigeron canadensis L. Other common names.— Erigeron, horseweed, mare’s-tail, Canada _ erig- eron, butterweed, bitter- weed, cow’s-tail, colt’s-tail, fireweed, bloodstanch, hogweed, prideweed, scabious. Habitat and range.—Canada fleabane is common in fields and waste places and along roadsides almost throughout North America. It is also widely distributed as a weed in the Old World and in South America. Description.—The size of this weed, which, is an annual, depends upon the kind of soil in which it grows, the height varying from a few inches only to sometimes 10 feet in favorable soil. The erect stem is bristly hairy or sometimes smooth, and in the larger plants usually branched near the top. The leaves are usually somewhat hairy, the lower ones 1 to 4 inches long, broader at the top and narrowing toward the base, with margins toothed, lobed, or unbroken, while those scattered along the stem are rather narrow with margins generally entire. This weed, which belongs to the aster family (Asteraceze), produces from June to November numerous heads of small, inconspicuous white flowers, followed by an abundance of seed. (Fig. 30.) 29 Fia. 30.—Canada fleahane (Leptilon canadensc), flowering tops. PLANTS FURNISHING MEDICINAL LEAVES AND HEBBS. 39 Collection, prices, and uses.—The entire herb is used; it should be collected during the flowering period and carefully dried. The price paid is about 5 to 6 cents a pound. By distillation of the fresh flowering herb a volatile oil is obtained, known as oil of fleabane or oil of erigeron, which is sometimes employed in attempting to control hemorrhages and diarrheal affections. The leaves and tops were formerly official in the United States Pharmacopceia, from 1820 to 1880, but the oil alone is now recog- nized as official. The herb, which has a faint agreeable odor and an astringent and bitter taste, is also used for hemorrhages from various sources and the bleeding of wounds. It is also em- ployed in diarrhea and dropsy. YARROW. Achillea millefolium I. Other common names.— Millefolium, milfoil, thou- sand-leaf, thousand-leaf clover, gordolobo, green arrow, soldier’s wound- wort, nosebleed, dog daisy, bloodwort,sanguinary, car- penter’s grass, old-man’s- pepper, cammock. Habitat and range.—Yar- row is very common along roadsides and in old fields, pastures, and meadows from the New England States to Missouri and in scattered localities in other parts of the country. Description.—This weed, a perennial of the aster family (Asteracex), is about 10 to 20 inches in height and has many dark-green feathery leaves, narrowly oblong or lance shaped in outline and very finely divided into numerous crowded parts or segments. Some of the leaves, especially the basal ones, which are borne on stems, are as much as 10 inches in length and about half an inch or an inch in width. The leaves toward the top of the plant become smaller and stemless. From about June to September the flat-topped flow- ering heads are produced in abundance and consist of numerous small, white (sometimes rose-colored), densely crowded flowers. (Fig. 31.) Yarrow has a strong odor, and when it is eaten by cows the odor and bitter taste are transmitted to dairy products. 219 Fic. 31.—Yarrow (Achillea millefolium), leaves and flowers. 40 AMERICAN MEDICINAL LEAVES AND HEBBS. Collection, prices, and uses.—The entire plant is collected at the time that it is in flower and is carefully dried. The coarser stems are rejected. Considerable shrinkage takes place in drying, the plant losing about four-fifths of its weight. The prices paid for yarrow are from about 3 to 5 cents a pound. Yarrow was official in the United States Pharmacopceia from 1860 to 1880. It has a strong, aromatic odor, very much like chamomile, and a sharp, bittertaste, It has been used as a stimulant tonic, for its action upon the bladder, and for check- ing excessive discharges. TANSY. Tanacetum vulgare L. Other common names.— Tanacetum, bitter but- tons, ginger plant, parsley fern, scented fern, English cost, hindheal. Habitat and range.—This is another garden plant introduced into this country from Europe and now escaped from cultiva- tion, occurring as a weed along waysides and fences from New England to Min- nesota and southward to North Carolina and Mis- souri. Description.—Tansy is strong-scented perennial herb with finely divided, fernlike leaves and yel- low buttonlike flowers, and belongs to the aster family (Asteracee). It has a stout, somewhat reddish, erect stem, usually smooth, 1} to 3 feet high, and branching near the top. The entire leaf is about 6 inches long, its general outline oval, but it is divided nearly to the midrib into about seven pairs of segments, or lobes, which like the ter- minal one are again divided for about two-thirds of the distance to the midvein into smaller lobes having saw-toothed margins, giving to the leaf a somewhat feathery or fernlike appearance. The yellow flowers, borne in terminal clusters, are roundish and flat topped, surrounded by a set of dry, overlapping scales (the involucre). (Fig. 32.) Tansy is in flower from about July to September. Collection, prices, and uses.—The leaves and flowering tops of tansy are collected at the time of flowering and are carefully dried. They lose about four-fifths of their weight in drying. Their price ranges from about 3 to 5 cents a pound. Tansy has a strong, aromatic odor and a bitter taste. It is poisonous and has been known to produce fatal results. It has stimulant, tonic, and emmenagogue properties and is also used as a remedy against worms. Fic. 32.—Tansy (Tanacetum vulgare), leaves and flowers. 219 - ey @ PLANTS FURNISHING MEDICINAL LEAVES AND HERBS. 4] WORMWOOD. Artemisia absinthium LL. Synonym.—Artemisia vulgaris Lam. Other common names.—Absinthium, absinth, madderwort, mingwort, old-woman, warmot, mugwort. Habitat and range.—Wormwood, naturalized from Europe and mostly escaped from gardens in this country, is found in waste places and along roadsides from New- foundland to New York and westward. It is occa- sionally cultivated. Description.—This shrub- by, aromatic, much- branched perennial of the aster family (Asteracez) is from 2 to 4 feet in height, hoary, the young shoots silvery white with fine silky hairs. The grayish- green leaves are from 2 to5 inches long, the lower long- stalked ones two to three times divided into leafiets with lance-shaped lobes, the upper leaves gradually becoming more simple and stemless and borne on short stems and the uppermost linear with unbroken mar- gins. The flower clusters, appearing from July to Oc- tober, consist of numerous small, insignificant, droop- ing, flat-globular, yellow heads. (Fig. 33.) Collection, prices,and Fig. 33.—Wormwood (Artemisia absinthium), leaves and flowers. uses.—When the plant is in flower the leaves and flowering tops are collected. These were official in the United States Pharmacopeeia for 1890. The price paid for wormwood is about 4 cents a pound. Wormwood has an aromatic odor and an ex- ceedingly bitter taste, and is used as a tonic, stomachic, stimulant, against fevers, and for expelling worms. An oil is obtained from wormwood by distillation which is the main ingredient in the dangerous liqueur known as absinth, long a popular drink in France, in which count ry; however, the use of the oil is now prohibited except by pharmacists in making up prescriptions. 219) 42 AMERICAN MEDICINAL LEAVES AND HERBS. COLTSFOOT. Tussilago farfara L. Other common names.—Coughwort, assioot, horsefoot, foalfoot, bull’s-foot, horsehoof, colt-herb, clayweed, cleats, dove-dock, dummyweed, ginger, gingerroot, hoofs, sowfoot, British tobacco, gowan. Habitat and range.—Coltstoot has been naturalized in this country from Europe, and is found along brooks and in wet places and moist clayey soil along roadsides from Nova Scotia and New Brunswick to Massachu- setts, New York, and Min- nesota. Description.—In_ spring the white-woolly, scaly flowering stalks with their yellow blossoms are the first to appear, the leaves not being produced until the seed has formed or at least toward the latter part of the flowering stage. The flowering stalks are several, arising from the root, and are from 3 to 18 inches in height, each one bearing at the top a single, large yellow head, remind- ing one of a dandelion, having in the center what are called disk flowers, which are tubular, and Fic. 34.—Coltsfoot (Tussilago farfara), plant showing root, leaves, surrounded by what are and flowers. known as ray flowers, which are strap shaped. When the seed is ripe the head looks somewhat like a dandelion ‘“‘blow.” The flow- ering heads are erect, after flowering nodding, and again erect in fruit. The bright- yellow flowers only open in sunshiny weather. They have a honeylike odor. The leaves, as already stated, appear when the flowers are almost through blossoming, or even afterwards. They are large, 3 to7 inches wide, almost round or heart shaped in outline, or, according to some of the names applied to it, shaped like a horse’s hoof; the margins are slightly lobed and sharply toothed. The upper surface is smooth and green, while the lower is white with densely matted woolly hairs. All the leaves arise from the root and are berne on long, erect stalks. (Fig. 34.) Collection, prices, and uses.—All parts of coltsfoot are active, but the leaves are mostly employed; they should be collected in June or July, or about the time when they are nearly full size. When dry, they break very readily. Collectors are paid about 34 cents a pound. Coltsfoot leaves form a popular remedy in coughs and other affections of the chest and throat, having a soothing effect on irritated mucous membranes. The flowers are also used; likewise the root. 219 PLANTS FURNISHING MEDICINAL LEAVES AND HERBS. 43 FIREWEED. Erechthites hieracifolia (L.) Raf. Synonym.—Senecio hieracifolius L. Another common name.—Pilewort. Habitat and range.—Fireweed is found in woods, fields, and waste places from Canada to Florida, Louisiana, and Nebraska, springing up in especial abun- dance where land has been burned over, whence the name “‘fire- weed.” Description.—This weed is a native of this country and is an ill- smelling annual belong- ing to the aster family (Asteracex). The stem is from 1 to 8 feet in height, grooved, branched, and juicy. The light-green leaves are rather large, from 2 to 8 inches long, thin in texture, lance shaped or oval lance shaped, the margins toothed or some- _ times deeply cut. The upper ones usually have a clasping base or are at least stemless, while the margins of those lower down narrow into the stems. Fireweed is in fl6wer from about July to Sep- tember, the flat-topped clusters of greenish-white or whitish heads being produced from the ends of the stem and branches. The green outer covering of each flower head is cylindrical, with the base considerably swollen. (Tig. 35.) The seed is furnished with numerous soft white bristles. Collection, prices, and uses.—The entire plant is used and is gathered in summer, The leaves turn black in drying. The price paid to collectors ranges from about 2 to 3 cents a pound. An oil is obtained by distillation from the fresh plant. Fireweed has a disagreeable taste and odor. It has astringent, tonic, and alterative properties. 219 Fic. 35.—Fireweed ( Erechthites hieracifolia), \eaves and flowering tops. 44 AMERICAN MEDICINAL LEAVES AND HERBS. BLESSED THISTLE. Cnicus benedictus J.. Synonyms.—Centaurea benedicta 1..; Carduus benedictus Cam.: Carbenia benedicta Adans. Other common names.—Holy thistle, St. Benedict's thistle, Our Lady’s thistle, bitter thistle, spotted thistle, cursed thistle, blessed cardus, spotted cardus. Habitat and range.—The blessed thistle is a weed which has been introduced into this country from southern Europe and is found in waste places and stony, uncultivated locali- ties from Nova Scotia to Maryland and the South- ern States; also on the Pacific coast. It is culti- vated in many parts of Europe. Description.—In_ height this annual plant of the aster family (Asteracez) scarcely exceeds 2 feet, with coarse erect stems, branched and rather woolly. The leaves are large, 3 to 6 inches long or more, oblong lance shaped, thin, more or less hairy, with margins wavy lobed and spiny. The lower leaves and those at the bottom are narrowed toward the base into winged stems, while those near the top are stemless and clasping. The yellow flower heads, which appear from about May to August, are situated at the ends of the branches, almost hidden by the upper leaves, and are about an inch and a half in length. Immediately surrounding the yellow flower heads are scales of a leathery texture, tipped with long, hard, branching, yellowish-red spines. (Fig. 36.) Collection, prices, and uses.—The leafy flowering tops and the other leaves are gath- ered preferably just before or during the blossoming period and then are thoroughly and quickly dried. In the fresh state the leaves and tops have a rather disagreeable odor, which they lose on drying. They are bright green when fresh and grayish green and woolly when dry. Collectors receive about 6 to 8 cents a pound. The taste of the blessed thistle is very bitter and salty and somewhat acrid. It is used principally as a bitter tonic. 219 Fic. 36.—Blessed thistle ( Cnicus benedictus), leaves and flowers. i ip, SeEIMERE EERE 318 WOFID WOOO <...224:. 2-2 nade nqsetneek ee aet Archangel, green and purple, same as bugleweed..-....-.....----..---------- Arctostaphylos glauca, distinction from bearberry........:----------------- Hva-ursl, description, range,'uses, ete.2.8-..4 22-6255 -= eee Mromaiie winierereen, Same as wintergreen . .....<..-~--.252-522t es BPM OUEA ChE DEAT DERE a 56S ore 2 = ett ot Se eee oe Beerpmbeery, (Site: As DCATDEITY oi 25 oe eee = om da cigs = Seeley Serres OLE ASSORTED CEEY. oo 5a aia ow ae a ws le Si ae wie a pan fa = i meal ae Rete ut AA VETS BAITS so os ee a a toe oe a pe a = SUEmmrIDUCrry, BAING AS DEALMOEDY wsvins a selene a 40 Dero, nameias DaAlmony.. ..;- +. .s.. ho. eee .522.....2..02.55..2 20.2. 2 ee 38 Common evening primrose, same as evening primrose... .....--------------- 14 liverlcaiesam eras iy Chl Caltech ta s5 5a2.5- 0s ct poe = see ge ee eS 10 Bpecd well, description, range, Uses, elC@. 22. = =...6 = < Sgn a ee de ae 42 Dm MERRY elise ASS TUAW “VENG 5 2.5 <2 = eo ao ei == Lee Hothead sates ae eee 34 imei ne as Canada fleabane. ...-..--. =. - ect ame nsencans sob Eos 38 Damiiwdris same-ag motnerwort. <. .<2<~~ ~~ s.s- vale scenes - Beech a. Sosa Ee eid 222 Sl 2 22021-22222 eee eee 32 thimbles,.same'as foxglove. 2. S220. 12. 22. . SPL I. A 32 Helonwort, same:as celandine...: 2/9. 202-<2 St eS ee eee i! Fern bush; same as sweet fern: 222. ie. 222 eS SE eee 9 pale, same as sweet fern on ee Se ee 9 meadow, same as sweet fern.............-.----.---------------------= 9 parley, same as taisy.- 0.222220 2 jones 2 oe 40 scented, same as tansy. :)..21.02.0 20: 220 2. Se 40 shrubby; same as sweet ferns... 22 222552-29)22 525 Se 9 sweet, description, range, uses, etc... ........ 3-217) 2022 eee 9 Ferry, sweet, same as sweet Bern ......-.--.--- 2202 2-S 2202-22 9 Fever plant, same as evening primrose. -...-.. 22/5222 22. 52-2298 oe 14 Feverwort, ‘sameas boneset_@& -/..f2:20. 5. S52 ee eee 36 Field evening primrose, same as evening primrose.......-.--.--------------- 14 mint, same as catnip. 22-22.-l221..0.. 2.2.2. os eee PS Finger flower, same 9s foxglove..{.:..-.2..2.-..2--22 2-4 Ji: Oe eee 32 Fingers; fairy, same'as foxplove:-)...-.2. 2.1... Sea Peso eee Ree 32 Fireweed, description; range, uses, ete .2-. 0. 122 doe A ee 7,43 same as jimson weed and Canada fleabane,..............------- .-- 30,38 219 INDEX. 49 Page. Fishmouth, same as balmony........ 2. ARR ce Celi) sate ey eee 31 Semeneneae: 25, 1OXPlOVO. os ee a ee 32 Fleabane, Canada, description, range, uses, etc................2..---.----. 7, 38-39 pemeene ene As FOXPIOVE,. 2 - 0s ses e050 aos 5 vee eens bless 40 Hive. vine, same AS BGUAW ViNe. ..... ..-.-2- sesh deen » «pir se - Seva 34 Hogweed, same as Canada fleabane.......-....-...-++ qpevk teow eee Ee 38 Holly, ground, same. as pipsissewa. . ..... ~~. . - <0 simi Be ee 22 Hoodwort, same as skullcap... . - 0 -sxe5+ ... 2.2202 2.8. 062. 2222 pee 21 Horehound, American water, same as bugleweed...........--..-.-------+---- 27 description, ‘Tanpe, ses, ete...) 2. 2) 22 <2. see tle se ee ee 23 Virginia, same as bugleweed. . ...- -.-. .. 4sod000}-ue ape - 27 Horsefoct, same ‘as coltafoot: 2.2. a... P22 Sat. 2 2 2 eee Sap 42 Horsehoof, same as coltsfoot...........---- Sésaglss se ce. :.: san 44, Horseweed, same as'Canada‘fleabane: |: .2. 52022.) 532 ie. 2 25 eee 38 Houndsbene, same as horehound...........--.----- Ai a3 S5 <=2ign.o ae Seen 23° Tidian sage, same as bonesets. $7. ¥-s2adetins ay. eens - eee oe 36 tobacco, same as lobelia. .......-..--- igor fee eo eee 35 Tsaac, wild, same as. boneset...... 2. -- gn os 28 See eee oe er 36 Tvory plum, same as wintergreen. ......-.--..:--2.--.<----2--; + eer 19 Tyy; big-leaved, same'as mountain laurel... . 1.2. 2.2 ee 17 bush, same as mountain laurel... 0.0220. .2.225. 01.2. iF flower; same ‘as liverleaf.. 2.0). 222222 220 LT 10 Tyyberry; same as wintergreen ...2..2 0.022.022 2 2222 19 Jacob’s ladder, .3zame as:celandine. -....-.--+.--.... S=eeeesbe pea ee 11 Jamestown lily, same as jimson weed......--.~..icale Joo-95- ee 22g 30 weed, same as jimson weed......--.-.--s2i2otGl!-6e 3eee 30 Jimson weed, description, range, uses, etc.........-icisus=b2 Se ee Soe 30 Kalmia, broad-leaved, same as mountain laurel... .......-..-------------.- if latifolia, description, range, uses, ete.......-..2---.-.-. =. ee eee 17 same as mountain Jatirel. -- 2... 7.222.520 29. ot ee 17 Kidney liverleaf, same as liverleaf:.... 2... - <-<-. 2 9 10 Killikinnic, same as bearberry ...:....-222222- 22-22 -e 2. eee rr 20 Killwart, same as celandine..---.- .:---..22.: 25-2 -2-2-2= 52-2 == 11 King’s cure, same as pipsissewaisi./o:')2. 2. 5-1 22249-l. see 52ae -oene 16 cure-all, same as evening primroses. ..): 242 #22 /2b-e= tt Sse ee 14 Kinnikinnic, same as bedBberry.... ..)0. 92.0: -2d 2.8 -es-e +280. Fees eee 20 Ladder, Jacob’s, same‘as'celandine ......2..-.----0-n----7-- 75008 eee i1 Lady’s-finger, same as foxglove........-..--2--=<-22re--7e- +r ose eee eee 82 glove, same as T0xPlOVC..).... <2 m5 = ota ee cent oe ee ee BASS. 32 thimble, same'as foxgloves ... 2. 2.2. 2 wis oie eu sincene oe eee 32 219 INDEX. Lamb mint, same as peppermint and spearmint................-....22.....- PeeeeeL. eae as peppermint. !°s\i 2. geses ees Jeobdbecet: euuiiolns soekled Baarel, American, same as mountain laurel... 2.2.2. Stone S2cis see or.d se: broad-leaved, same as mountain laurel.........................-.--- emund same as ptavel plants i. .... 42. oles ge-aeeee vedio pisuntain, description; ranze) uses, etc. .22. 2-22 seer eres ceil fuse pattie as‘mountam laurel. 3.2... <..2 2.12. POSSE eee ee olism: tee eiecppeamicias nidiintain laurel. ..... 02. yaLesetpwr soe estes /aecvee A pe amie as mountain laurel... <>... Jaeereadss- ee seu a boetd Beare tanmie'as mountain) laurel ....-... 52... 2s besa ct steko Mmaodmsane as mountain laurel. -25.230.. (2. sees ep Sree 2 et Leonurus cardiaca, description, range, uses, etc. ..........-.-.-.-..-2.-.2-2--- Leptilon canadense, description, range, uses, etc... ....-.--2.-22-..----2--- iis Jamicstown, same as jimson weed. . 2.2... foi ence o5-suies woswdwen ine entyeame as motunerwott. 222-2 2/5. 2-2. eee eee de seen fob ee PMR eIAS JORPIOVE: IS) 255.) 06 2... ssn See es eee METRE TAN SH OLNCBWOEL? 2)... = <2 %)(./-to-n a LE Here eee Liquidambar asplenifolia and L. peregrina, synonyms for Comptonia peregrina. - Liverleaf, acute-lobed, same as liverleaf..............- Settee. teeny ahh eormmonssamejas liverleaf... - ..-... tes were Se eee, Lee BonenpiOn, (Fanse: uses, ete vic. tli BOs: . eed dom eee Noe Peerane as iaveriGafs 200. .......... tyre seed Sec Bazey 2 eal Gaauey, same as-liverleag-.,... 2... sia .xose. Sap teh nce eee oped same as liverlesf2 i005 |» ete ihece soe cad. Peemmee meas bverleafis .0292.. $9..-. 5 .2..2eeesd seed une seen . gehen. Pevetwont eum tune las liverleaf 506.5... yoeeheee’ = eattele. eurgsbeety |. Buble enune as Jiverieat ioc oer. . oes ood a ereels feel - o peepee er epee) 22S Lo eyes Le depen np! etree of Adee 2 Pea oe tien pale as Plpsissewa. 2 52.520... .2. 22 eee ee de ee ee! Mawar same annOUelae.. Sele eae oe 3 oe ee. oe Se Se Lycopus virginicus, description, range, uses, etc. ..-.......----------------- Peer N etn Hamme AS SPCAarMUNt. . = oo iad each ac eat denwae ees emesis RARE AN PMIEDH WCE... 2-22. se eo Hoge oth oss ty. Joes Madar aoni a sari as WOLMiW OOM fot). 2 aie oe Bomepioete ee eee Sees Mi ateomcnnoay. same as BiWllcap.......- =. - ---22c 2 25-2 ycioeedep ween See RIOR CEANIDCS SEE ITAL ie ec ns '2' sd) ee Se ee Mgmt Ganiincwon Irom bearberry ...-.....-....<<. 02-225 .s2+----2 2-555: Perce le same as Canada Heabane. sis. aay - yoy. Soe Seeds sep Loge eee aS HOTEHOUNG 250 2 Jo20'. sls! 1). Da) styie eee anh -.-. Marrubium and M. vulgare, description, range, uses, etc. -.-- fare mossy. fishen Merrrcinver same as buck: bean... 2...) -.. acu ey, soe eee ee Heil ame as DUCK DEA A .6. 2fe 2 fo aS 2 Oe PASS, A eee eerie NOrenOUNG. ..-<. .. Jena’ SNe | eer sees: Wale ais Meayuowermemie 2s Pravel plant...) -.. 22-2 Bol -y goin e Matibwaeri same a8 Sweet ter. = 22 o002 2... SS eh Le IS eaeemey ae aH DPAEDEITY...-....-... 8 see ea! ee ee oO. Mentha piperita, description, range, uses, etc. ............ SOE Sy Bipleshe CHT ION |TANCG, SEH, CLC 5582. ns ence ee ee eee 219 38-39 30 ee) bo bo bo w me bo bo CoaOwre - 20 28-29 29 52 AMERICAN MEDICINAL LEAVES AND HERBS. Mentha viridis, pharmacopceial name and synonym for M. spicata............ Menyanthes trifoliata, description, range, uses, etc....................0..004. Mercury, Scotch, same as foxglove.....0/23/0. 002000. 0 2). a Milfoil, same as yarrow. .........--.-/02 088 LSU Oe A Milk, devil’s; aameias celandine. ....... 01. ..0s5) JOUR PO Millefolium;.same:as: yarrow. ..........00. J080. SRST SOUL, Minpwort, same se)wormwood .... + 2... - 2 SP SAY @. ve Mint, American, same as: peppermint... ... 2.02.00. Dect. 2 brandy, same\as peppermint...........0505. 202) 0 brown, same asspearmint... ........///00t SOO Oe Gold, came As CAIP ie. on in eo. nie wee SRO Lee. UR garden, same as spearmint. .....22.041. 208) ANU 00) . ae lamb, same as peppermint and spearmint..............2...222222....- mackerel, same as spearmint... ........ 020.02. 0.. 0) J Our Lady’s, same asispearmimt... 20.2022... dO, >. Ue Sale AS SPCAFMILNb. 62)... eee een e er nase tee yee ULES 08 Sr squaw, same as pennyroyal...............-.... 20 LeU State, same as peppermint... 0.00.5... 0 i000. Mitchella repens, description, range, uses, etc..............---22--.2.2222202 Mock pennyroyal, same as pennyroyal. . ........2) 9211.94 0p. Moonflower, sameias buck bean=-/22-22.:.......02. AONE et Mosquito plant, same as pennyroyal................22UI22.4 SE Motherwort, description, range, uses, etc..........2052.. )3.070L. 1 Mountain balm, same as yerba.santa..........20 3351. 22. ee box, same as bearberry . - .-..--.-...--~..<-..ute 2 Ue cranberry, same ds bearberry..-. . . .....:¢2'201v.. A. 00S laurel, description, range, uses, etc......200 22s. 4 2 See pink, same as gravel plant..-........ =... 2. -.. 12 2 tea, Bame as Wintergreen. ........ geil. Sate Mowise-ears; same as liverleaf.....:.: s¢u¢. 2005) .WOL 2 ). Se Nepeta cataria, description, range, uses, elc.........--.----.----- =.= Night willow-herb, same as evening primrose.............-.----.--------+---- Noble liverwort, same as liverleaf..--...........2:::272--"2 2) rr pine, same ‘as pipsissewa.- ==. -.:-..22-2222:52.5°5- 2. - . INosebleed, same.as: yarrow = ....- aul) Sek Dees sesh 19 PEMMMMCERCRNG AE JORPIOVO: .. 2 5 asi nioses 5+ 5e as SHOE IOI IR 92S 32 Prices, approximate, of medicinal leaves and herbs.........-.......--------- 8 See also under each plant described. mrdeweed. same as Canada fleabane......2ui.42 2.0.68 Joie ke eee. 38 Primrose, common evening, same as evening primrose ..................--.- 14 evenimpe. description, range, uses, tess... ly. Hei ee 14 field evening, same as evening primrose........................--- 14 ffeo KamMe.as evening primrose: .....< less see. 2S as Le 14 wild evening, same as evening primrose........................--- 14 iio mieiae wea AS GIPSISSOWA: ¢ - - 2-255 - 2242s ee ane PUA Ls 16 be eee ieee 88 IODENM A - 2... 5.2 4. 2. te See Sb SO. I 888 GIL 35 Borplearchancel, same as bugleweed:: - 22.25... .)\ sles seth. ce wtiedo saben 27 iemramvegnaine an tOXSlOVC(-.... tsa: hoses -jsce eos Bb aes diane <= 22 2 32 Peer eat PUPAE WA 2S. soe -< <= oss = «> <' 2 x SNE tie qo SEA oS 16 umbellata, synonym for Chimaphila umbellata.....-............-..-- 16 Sener. SAMO aS ORPIOVE),. 3. ---<25 002 -5e8 sates cas - 5-2 2 obese 5 ne 32 Pepa, litee, came as evening primrose. .-:1:2.5-2---..-..-.----..+-.--)---- 14 Rapper dandies, same as wintergreen and bearberry.....-...-.-.-------------- 19, 20 PeCePatneety eatteas DeATDeIry 2. /.8 ces Le ee te Pe. 20 Paeleie amas Winberpreenl. oooh. < ss. VEE ee eee ee 19 ieedberry tea, same as winterpréeen...22. 2220-222 SPL ee. 19 Rheumatism-weed, same as pipsissewa.........------2..-2----------22252---- 16 Peete rete an HEATUCITY . 0 2s 22 kc CUP Be PR J oro eee 20 Hose arel. same as mountain laurell...s2. <1 J22 ee. 4. See Se ee 17 Round-leaved hepatica, same as liverleaf................---2.----22.+----/-- 10 inser DU, Wild. Haine as SQUAW VING...-2-<-:.. sate. Seewew on bee we seeks - 34 ppeanmmemmimretiiie ty DEATDCI Ys... <2. oo e's ee oe hs wk ae ne a nw vce 20 Pp eCmbn adele SATE Tad DONESCUS om6 ances cesses oie to -o opelsle opis sss ae sso we 36 GHeerunehen: Same'as spearmint.\. 222.0505. 7-5-2 2 ee eee eee 29 mat herMEnetiite as DOMeSseltaet tet Meters ora) trcie eats aeeeenne Bie See cine emote 36 peaenedici-s thistle: same as‘ blessed: thistle: ::::-03.0-2.2-..2....c00-e0--s- 44 Baienie ey Code aro ast DalMONy aoc2 21) 1-!sfele tes eae wee eee ores ces tenes 31 Senay MBAR C ABSYVALTOW? 1%. %/- 22! bi-Ue alee Uae e tice cece eee e bees. ce atic 39 Scabiousweamelas Canada fleabane 22 eee eit AS es eS 38 219 54 AMERICAN MEDICINAL LEAVES AND HERBS, Scabish, same as evening primrose... os 5.29% sid ee DL te oR SEU Sealy grindelia, same as gum plant........0.-- «054 lk Mevaes ob OSE ee Scented fern, same as tansy. sso. e. esis. Vdd wees ell fi See Scotch mercury, same.as foxglove.........ev.ccwieans é2).eie. ee Scurvish, same.as evening primrose......... 5% .esss Hui). Jaa eee Scutellaria and S. lateriflora, description, range, uses, etc...................- Senecio hieracifolius, synonym for Erechthites hieracifolia...... . Sool. Ue Senna, American, description, range, uses, etc ..........2.52.-25-2200..00008 marilandica, synonym for Cassia marilandica.................-.+-.---- wild, same as American senna...........-.g00 iis Glen Shadflower, same as gravel plant .....-----.-.---.-.e Usui. 50 Se Shamrock, water, same as buck bean ..............s00svsec)i WL Soles 2 ee Sharp-lobed hepatica, same as liverleaf.............-.2..2.222.60.0000. 008 liverleaf, same as liverleaf.............2........ . Jide. Sheep laurel, same as mountain laurel... -..-. : evs ye .. Joga Shell flower, same as balmony......... .dd0:d.lunevtek. beeper Shrubby fern, same as,sweet, fern. ..............-.-.2ssniUVil = So Side-flowering skullcap, same as skullcap ........-:--.--......---+-+--es000- Skullcap, American, same as skullcap...............202 712.4 4 ee blue, same.as skullcap. icc: 6 oon sn eer men selene a SE description, range, uses,-ete.!. 04.02: 00. Legis Jeet lo. S20 ca mad-dog, same as skullcap ..........s2csnsees Jed. co side-flowering, same as skullcap. ...... 2.2.20. «..nis' J. SERS Small laurel, same as mountain laurel ...........--.-.-- . itive 1s eRe Snakeberry, same as squaw vVine....--202. 200. .cuait 220 lgieeed: eee Snakehead, same.as balmony .....9cesicus0-2ci:e0s-a8 22898 .22 Se Snapping hazel, same as witch-hazel..........22 20204 2 Wie 2 A Oe Soldier’s wound wort, same as yarroW.s22s2-20 2225.5) coe 2s. eR Sowfoot, same as colisioot..............=.----.-.--8 0 See LG 38 Spearmint, description, range, uses, etc -......-.---.------ Jel.) Speedwell, common, description, range, uses, etc..............-.------2--20- upland, same as common speedwell.........-....---.---- eer se Spiceberry, same as wintergreen. ....--.--......-22:=::2+ 0! See Spicy wintergreen, same as wintergreen .........-...------------ Eg Spleenwort bush, same as sweet fern....-.--=-=---+--.-225-3--->---- =e Spoonhunt, same'as mountain laurel. 22... .2 2... -------~---- +> <==" Spoonwood, same as mountain laurel.¢...24--. .------<--------+-=--—=— eee Spotted alder, same as witch-hazel.........: . =~. --mcmte-n¢ -m- .--2 == ose aeremap eee Squirrel cup, same as liverleaf. 2.2. 2200202 S022... aa nee wee - State mint, same as peppermint. -.-......-..-.. ey Stinking balm, same as pennyroyall:. .2.25,: 4. p.c23 tes spaces tee ain tae _Stinkweed, same as jimson weed...........-.-------0s2---2ccececeeneenenes Stinkwort, same as jimson weed .......-----------++.:--demia~-as seme Storage of medicinal leaves and herbs, directions. ............--------+-++--- 219 INDEX. 55 Page Siramonulum, description, range, uses, etc.....---22 scenes ewase nes. os- 8s ote 30 Bemmmraraioer, Game 85 WitCh-Dazien oa oan a = ca ce rere rere eeeey « «2m of2t = ya 12 ErEMlouamOn sane as CelanGinO. ss ate O20 Sen Sees Saami oan oo a belserae 11 Reeerer plant, same as bonesety'. 225888 2A oe Se 36 Sweet bugleweed, same as bugleweed................----- SAS, ETS NUE: 4 27 nishesametas sweet ferns s.25 222 er. re Ee Fe LE 2, MOD ELAIES, 9 fem description, Tange. uses, Che 22.50: 2 322 see Se a 9 SRMEMCLMEG AN SW ORL ORM: 2 5. 2s gue 0,5 she ee i ee eae 9 gale, Canada, same as sweet fern.......-.--.-- is Se eS Py Sneath neve INE 9 Rane Tn es Ae An KLANS Viet 2 cic yore ee see ee ee nee ete 2 en eee ONE 40 Willgare., description; range, Uses, et 2 .a..-- pst te Oh 40 etme aenctipitom range, lises, ete... 0.08. .k AP eee Fee oe 7,40 Simmer eran i Verba, Santas G5. 225252 e ne se eee eae = ae et ee 15 eamCanadian. Sarie as Wwinterereeni. .. 2 5.2). <2 os 2 een opine oe eee Dee eee 19 Gunna Gong AA WIMtCreTeeM so.) 5. sce ke eee sae oe 2 vee teen 19 eenerhy. MAING AS WINLETPTCON) 2(.. 2. bo ooo ge ee ee a 19 Sipe pemmer aS a WVENILOTOVCOD. 3 2 ek i 19 PRE CME TET ORAS TON CRC Taek fa oS = Mitac Ne ino = se ek EN ee 36 “TT epaiel . GOMES PYSE | OTe TA =< (rele ee glee eee pee ees SS fee ye Sa eae 36 Men cinmnnimsaitioras Celangine. 2... 4 eeiac: osc eee ee eee il Mnamblesand fairy thimbles, same as foxglove.......~-.- .=-----,---»------- 32 Miustlewpither, same'as blessed thistle.....:....-...-. 222. -- ame = See 20 speedwell, same as common speedwell...........------.-----+e+-ee0- 32 Uva urei, description, range, uses, €6C. ... . - - 4.5. avees -mwee> =a bie 20 Vegetable antimony, same as boneset...-....-..-..---------2--2ccceueeenen 36 Veroniéa officinalis, description, range, iises, ‘ete............... 0 32 Virginia horehound, same as bugleweed..............---+-.eve=s. seen eee 27 Momitwort;same'as lobeliagie: = 2% sn fae acme eee oe ek bee 35 Warmot, same.as wormiuwood .-...52.2-.-.2.2..5.. 02-20 -p she oe 41 Wart flower, samoe:aa celandine....-..-.-..222212222.2.02 2 ane se ee 11 Wartweed, same as celandine:._...:.....5..011 02-22-50" oa IMS SAUNAS WASHINGTON: GOVERNMENT PRINTING OFFICE, 1911, aArPmaa BUREAU OF PLANT INDUSTRY. Chief of Bureau, BeverLty T. GALLOWAY. Assistant Chief of Bureau, WILLIAM A. TAYLOR. Editor, J. E. ROCKWELL. Chief Clerk, JAMES E. JONES. Crop ACCLIMATIZATION AND ADAPTATION INVESTIGATIONS. SCIENTIFIC STAFF. O. F. Cook, Bionomist in Charge. N. Collins, Botanist. L. Lewton, Assistant Botanist. . Pittier, Special Field Agent. T. Anders, J. H. Kinsler, Argyle McLachlan, and D. A. Saunders, Agents. B. Doyle and R. M. Meade, Assistants. 220 2 LETTER OF TRANSMITTAL. U. S. DeparTMentT oF AGRICULTURE, Bureau oF Puant Inpustry, OFFICE OF THE CHIEF, Washington, D. C., April 15, 1911. Sim: I have the honor to transmit herewith a paper entitled “ Rela- tion of Drought to Weevil Resistance in Cotton,” by Mr. O. F. Cook, of this Bureau, and to recommend its publication as Bulletin No. 220 of the Bureau series. It has been ascertained that dry weather gives a distinct advantage in the production of cotton in the presence of the boll weevil. This relation is being taken into account in improving varieties and cul- tural methods in the direction of weevil resistance. The present re- port shows that several biological factors must be considered in the study of the practical problem of securing a rapid, uninterrupted development of the crop. Respectfully, Wo. A. Taytor, Acting Chief of Bureau. Hon. JAmes Wison, ; Secretary of Agriculture. 220 3 or aiteintt « portaatteliics ati Eiri ioteors vf hein SATTIMAHART 40 SUTTS ae - Coed oe oe ey vwrayas] Tv Adl so Wasa wae) wer ww eprerO ALUT ua} bY We Bucy. >» +S «fas atlas 4 \ was AS whet Dalit ting bi Watt Werenily Oh ‘yo OSes bw? 4). abt Amott itt soremaiasnH, [i720 VE ot LATIN Y yi le titadl) Ves Veils a) iets’ hata - 7 ew flat wit bo saan cilia Bees Ta e F aes ly PHT? BVM PH whe Osite iy ger APs, tires ni),.ag ’ exgetstast: veo to epineil id tk fi (imine) ote eiaiost Inigelon! hyve hiresiiiol Digricg Wits To. sosiiodg -faatieen ALTE! 4B Sirad he My ovtlerth ae | eae eee wristy PL YI GON TENTS. 0 EAT a es Sept SR tle SR a I or Sok ee Complete cessation of weevil injuries during drought .-....-.--.------------ emnnendtt tH. Ory TCPIONS - |... 5-256 -- sesso na Sac ssnwseueencna= Improvement of quality by cultural methods. ..............---------------< Pere aieae ial DlOWINE SOUS... =.= <-- ane nono n e-em ess saesaeaSss--e—ne amrecapieIBtOiMlate PLANUINO - - 225, ascc.cssoccemaresaces seme cases wana asmnes Relation of drought to weevil-resistant habits of growth.........------------ Importance of dry weather in humid regions. ........-..----.-------------- Different types of earliness in relation to weevil resistance. ...-.------------- Importance of recognizing factors of weevil resistance. -......--...----------- Mageeiee SrA DIC VATICHECS <2... 5-55 onan eb oon n nnn c ain ee ns cesanesensns Difficulty of direct tests of weevil resistance.......----.-.------------------ COTUESTRL UAL Ry a ee SEES Tie a ee s(\ ve cute dusy 22 bodes harese tise vd Wii eee “ste dnse teen See di dessert octhettlh ssciuftel eed Sg cb ep eiaree ie andi el Aiwory Wi ath Ladd snataiast-li veo OF . otget Mend af t9ddeow a 4 ewaleiees Tew of pollebet a] weniht i = n2tetin Tiveaw to erotodl wetieher at’ UU Se .... era a nannies Then wié ema i? ee <<“ —. o- es eee nee) owe ~ ee ee BoP. T—6T1. RELATION OF DROUGHT TO WEEVIL RESISTANCE IN COTTON. INTRODUCTION. An important relation between weevil resistance and drought resistance has been recognized for several years past. Special ability to resist drought is to be reckoned as one of the factors of weevil re- sistance, because more drought-resistant varieties can be grown in the drier regions of the Southwest, where the weevils are often unable to propagate and do relatively little damage. A rapid exten- sion of cotton culture is taking place in this part of the United States. The farming public in Texas is coming to look upon dry weather in the early part of the season as the most important factor in the production of a good crop of cotton. At first it was supposed that the fate of the weevils during the winter would determine the possi- bilities of production in the following season. Measures for reduc- ing the number of weevils in the fall and spring received much attention, but it is now understood that dry weather makes it possible to secure a crop, even in a season when the weevils survive the winter in large numbers. In southern and western Texas the reduction of weevil injuries by drought is a very definite factor of weevil re- sistance, tending to place these regions more nearly on a basis of equality with other parts of the State for purposes of cotton produc- tion. In favorable seasons the same factor of dry weather becomes effective over much larger areas, as notably illustrated in the last two years, 1909 and 1910. In order to take full advantage of other measures for combating the weevils, the relation of drought to the behavior of the growing plants must be considered, no less than the direct effect of the drought upon the weevils. Questions of the value of early and late varieties and of early and late planting require to be reconsidered and given further study now that the effects of dry weather are more fully appreciated. It is only by a careful study and full recognition of all the factors that the true possibilities of cotton culture in the presence of the weevils can be realized. 220 8 RELATION OF DROUGHT TO WEEVIL RESISTANCE IN COTTON. Without a supply of moisture in the soil the same drought that hinders the reproduction of the weevils will also stop the growth of the plants, thus reducing the advantage that might be gained from the dry weather. But if the land has been well prepared by deep plowing and thorough cultivation so that it absorbs and retains moisture, the plants continue to grow and set their crop through the dry weather. The weevils do not prosper during drought because the young larve are killed when the infested buds fall off and lie exposed on the hot, dry ground. The importance of thorough till- age is especially great in the very compact impervious soils of the “black-land prairies” that produce a large part of the Texas cot- ton crop. Unless such soils are stirred by cultivation very little water penetrates beyond the surface layers, and these are very soon dried out. Under conditions of humidity other factors determine the success or failure of the crop. Wet and cloudy weather is likely to interfere with the growth of the plants without checking the propagation of the weevils. The more humid the climate the greater the necessity for a rapid, uninterrupted development of the plants if a crop is to be set before the weevils can prevent. With conditions continuously favorable the weevils can seldom cause any complete loss of the crop, but if a period of unfavorable weather interrupts the growth of the cotton after the first crop of buds has been infested, enough weevils may be bred to infest all the subsequent buds, so that no crop can be set. The luxuriant growth of the plants may continue, each producing hundreds of flower buds, but all pruned off by the weevils. A whole field of the overluxuri- ant weevil-pruned cotton may not average more than two or three bolls to the plant. The idea of avoiding weevil injuries by early planting needs to be supplemented by a recognition of the importance of securing an uninterrupted development of the plants. The chief object to be attained is the early setting of the crop in as short a period as pos- sible after the plants have begun to produce flower buds in which the weevils can breed. This object should be taken into account in the breeding and adaptation of varieties and in devising improved methods of culture for weevil-infested regions. COMPLETE CESSATION OF WEEVIL INJURIES DURING DROUGHT. The condition of the cotton on the San Antonio Experiment Farm in the middle of July, 1909, afforded an unusually striking illustra- tion of the importance of dry weather as a factor of cotton produc- tion in Texas. In spite of the fact that weevils appeared very numerous in the same fields early in the season and infested nearly 220 CESSATION OF WEEVIL INJURIES DURING DROUGHT. 9 all of the first buds, no damage was being done in the middle of July, nor were there evidences of any recent injuries by weevils. A care- ful search over several different plats of cotton failed to find a sin- gle bud, or “ square,” with a normal weevil puncture. Weevil larve could still be found in very small numbers in old squares on the ground under the plants, but almost invariably dead or dying. Not a single adult weevil was found. The only weevils that appeared likely to survive were a few small larvee in some of the earlier bolls, and these would not do further injury in that season, for the larve develop very slowly in the bolls and are not likely to emerge until the bolls open at maturity. Careful examinations of the same plats had been made by Mr. S. H. Hastings, superintendent of the San Antonio farm, in May and June, when an unusually heavy infestation of weevils was found. Under date of June 14, Mr. Hastings reported that nearly all the buds had been destroyed by the weevils as fast as they were formed and that a total failure of the crop was threatened. Had the weather continued favorable for the weevils there was certainly no prospect that the later buds could have fared any better than their predecessors, but the advent of dry weather completely changed the situation and set a definite limit to the activities of the weevils. Similar cases had been observed in previous years when there seemed to be a lessening of weevil injuries as the season advanced instead of the increase that had been feared, but no such complete interruption of injuries by weevils during the growing season of the cotton had been observed. The effects of heat and dryness upon the weevil larve were doubt- less intensified indirectly by the influence of the drought upon the plants. Injured buds are dropped much more promptly in dry weather, and in severe drought even the uninjured buds may fall off, thus lessening still further the weevil’s opportunities of propagation. The result of the earlier falling of the infested buds is to expose the larve to adverse conditions at earlier stages in their development and for longer periods of time. The effect of the prolonged drought in completely preventing the continuation of the weevil injuries was not confined in the season of 1909 to the vicinity of San Antonio. The same condition of unusually heavy infestation appeared early in the season in the experiments conducted at Waco, Tex., by Dr. D. A. Saunders, and the same complete cessation of weevil injuries was observed with the advance of drought. Careful examination of several fields of cotton in the vicinity of Waco on August 18 and 19 by Dr. Saunders and the writer showed that no injury was being done by the weevils, though the insects remained active in more luxuriant fields on rich bottom lands of the same district. 100712°—Bull. 220—11——2 10 RELATION OF DROUGHT TO WEEVIL RESISTANCE IN COTTON. Though the conditions of drought that gave the complete protec- tion against the weevils were generally so severe as to interfere seri- ously with the growth of the plants and would undoubtedly have prevented the development of any considerable crop unless rain had come, the facts are of interest in their practical bearings upon the problem of weevil resistance. The complete cessation of weevil injuries, even after the weevils had survived the winter in unusual numbers and had begun to feed and breed in the buds of the young plants, makes it evident that the highest importance must be placed on the dry weather. The values of special weevil-resisting varieties and of special methods of culture must also be considered as means of gaining greater advantages from dry weather. EARLY PLANTING IN DRY REGIONS. The object that has been sought by early planting and by the use of early varieties is to give the cotton an opportunity to set as many bolls as possible early in the season, before the weevils have become numerous enough to infest all the buds and bolls and thus set a limit to the crop. A farmer who plants too late may have his cotton stocked with weevils from fields planted earlier by his neighbors and may suffer more seriously than they. The best plan would be for a community to plant all of its cotton as nearly as possible at the same date. The date should be selected with a view to securing the most rapid development of the crop, and for this it is necessary that the plants make prompt and continuous growth. The amount of weevil injury is determined by the relation between the development of the cotton and the reproduction of the weevils. Any loss of time on the part of the cotton by delay or interruption of growth can only increase the relative proportion of weevil injury and diminish the crop. Anything that gives the cotton an advantage over the weevils should be taken into account in the problem of weevil resistance, whether the advantage is gained by methods of culture or by specialized characters of the plants them- selves. The largest results are to be obtained by combining the cultural and the biological factors. If each farmer attempts to plant earlier than his neighbors, the product of the community is likely to be reduced, for two reasons: Cotton that is planted too early may be injured so that maturity is retarded instead of being hastened and the weevils bred in early cot- ton may inflict increased injuries upon the later fields. Cotton that has been severely checked by cold or by extremes of wet or dry weather in the early stages of growth often suffers a permanent in- jury, either by being stunted in growth or by becoming abnormal in other respects. A smaller crop is obtained and that of inferior 220 EARLY PLANTING IN DRY REGIONS. Te quality. And even if no other change of characters takes place, ex- periments at San Antonio, Tex., in 1906 showed that the checking of the growth of an early planting may render it actually later in the development of its crop than a later planting of the same variety in the same place. Later planting not only secured more cotton, but a larger part of the crop was ripened before a given date, in spite of the fact that the plantings were made side by side, so that the later rows were readily accessible to the boll weevils bred in the early rows." That the same result would be obtained in all cases is not to be expected, for these experiments were made under dry-weather condi- tions. But in the season of 1906 the summer drought was not severe enough to stop the reproduction of the weevils, all the plantings be- ing quite seriously infested. The later plantings might have shown still greater superiority if they had been isolated from the early plantings, but in that case there could have been no assurance that other conditions of soil and moisture were the same. If very early planting could insure a correspondingly early har- vest, it might be argued that cotton should always be planted at the earliest possible date, without reference to scarcity or abundance of weevils. But in view of the experiments mentioned above, showing that later plantings may overtake very early plantings and ripen an earlier crop, it is plain that early planting, like any other cultural expedient, must be used with discretion and not carried to an un- practical extreme. Of course, it is only in regions subject to drought that the weevils can be expected to become less destructive as the season advances, but in the dry regions of southern and western Texas this consideration seems to be of practical importance. Fields planted in May some- times mature a full crop before being invaded at all by the weevils, even in localities where fields planted in March have suffered quite severely. Though such complete immunity of late plantings from weevil injuries may be of rare occurrence, the fact that good crops are sometimes secured in this way often leads the farmer to take the chance of a late sowing of cotton after a winter crop has been har- vested or after some other spring crop has failed. The possibilities of late planting are obviously of much more importance in regions where winter crops can be grown than in more northern localities where the growing season is only long enough for the cotton and winter crops are not used, at least on land that is to be planted to cotton. A heavy infestation of boll weevils in the early part of the season interferes with the growth of the plants long before the fruiting 1See ‘“ Local Adjustment of Cotton Varieties,” Bulletin 159, Bureau of Plant In- ’ dustry, U. S. Dept. of Agriculture, 1909, p. 49. 220 12 RELATION OF DROUGHT TO WEEVIL RESISTANCE IN COTTON, stage is reached. The weevils begin by gnawing the terminal vege- tative buds in the spring, before there are any flower buds to feed upon. This hinders growth of the young plants and forces the growth of vegetative branches at the base of the plants instead of allowing fruiting branches to be produced early in the season. Weevil-infested fields of cotton can often be recognized, even at a distance, by changes in habits of growth, before the differences in yield become apparent. Such expedients as the picking of the adult weevils by hand and the poisoning of the leaf buds of the young plants are much more advantageous early in the season, not only in reducing the number of weevils, but in allowing the cotton to make more rapid and normal growth. Yet it is very difficult to determine how much advantage is secured from such efforts, owing to the great variation in seasons and in the abundance of weevils in different fields, or even in parts of the same field. Drought is more effective in holding weevils in check if the dry weather begins before the cotton plants are large enough to provide the necessary food and shelter for the weevils. If the plants con- tinue to make good growth during weather that is too dry for the weevils to propagate, the crop can be set and brought to maturity without serious damage, even in localities where earlier plantings have suffered severely from the weevils. This explains the very great advantage that is generally to be gained in dry regions by plowing the land in the fall and maintaining the tilth through the winter as a preparation for the planting of cotton, in order to have as much moisture as possible available in the soil and thus enable a more con- tinuous growth to be made during any periods of dry weather that may occur in the early part of the growing season. With proper attention to the preparation of the land, cotton can be grown even without irrigation in many districts of the South- west that have been looked upon hitherto as hopeless deserts. The drought-resistant qualities of the cotton plant are only beginning to be appreciated, perhaps because the chief centers of production have been located in humid regions. In localities where small supplies of irrigation water can be developed they can probably be used to much better advantage with cotton than with any other crop. The general danger in irrigated regions is the excessive use of water. The chief obstacle to the extension of cotton culture in the South- western States is the scarcity and high cost of labor, but the progress that is being made in the invention of cotton-picking machinery indi- cates that this limitation may be removed in the near future. 220 RELATION OF DROUGHT TO WEEVIL RESISTANCE IN COTTON. 13 IMPROVEMENT OF QUALITY BY CULTURAL METHODS. Cultural methods that allow a continuous development of the plants may also help to counteract weevil injuries. Interruptions of growth not only invite greater damage from weevils but injure the quality of the fiber. If the presence of the boll weevil can induce the farmer to adopt better methods of culture, better staples can be pro- duced, so that a lessening of the crop may be compensated by an in- crease in value. To improve the fiber so as to be able to sell small crops for as much or more than the former large crops would be a very practical method of reducing the losses inflicted by the weevils. Reduced production of long-staple Upland cotton in Louisiana and Mississippi is increasing the demand for superior varieties of inter- mediate lengths, from an inch to an inch and a quarter. These can be grown in many parts of the cotton belt where only short and inferior varieties are now planted. With the boll weevil as a further obstacle the tendency is for the careless farmer to give up the culture of cotton, but farmers who adopt the other precautions to make cotton profitable under weevil conditions are likely to take the additional step of adopting better varieties and maintaining the uniformity of their stocks by the neces- sary selection. Longer and stronger staples could be produced over a large part of Texas if better varieties were grown and better methods of culture were applied, so that the fiber could be properly ripened instead of growth being suddenly checked by drought and the bolls opened pre- maturely. Even under conditions of extreme drought it is possible to produce fiber of good quality if the plants are not checked. Though plants that develop under dry conditions may remain very small for lack of moisture, they may still produce excellent lint. This was well shown in experiments at San Antonio, Tex., in 1910. A season of continuous drought produced better fiber than the pre- vious year when the drought was interrupted by a rain at the middle of July. The rain allowed a larger growth of the plants, with larger demands for moisture, but no other rains came to maintain the supply. Though the rain undoubtedly increased the crop, much of the fiber suffered in quality because the plants were checked during the fruiting period and the bolls opened prematurely. In localities where irrigation facilities exist, even a very limited supply of water could be utilized to great advantage in bringing the cotton crop through to maturity. Where water is to be had in the winter, but without facilities for summer storage, winter irrigation may be practiced as a preparation for the cotton crop, the water being retained in the soil by the same methods of tillage as in dry farming. There is an unfortunate tendency in irrigated districts to apply 220 14 RELATION OF DROUGHT TO WEEVIL RESISTANCE IN COTTON. water to the growing plants too early in the seasen. The result is to stimulate an undesirable vegetative growth and make the crop late, thus increasing the danger of weevil injuries. In the drier districts of southern and western Texas the farmer depends more upon the moisture already stored in the soil than upon rain that falls during the growing season. To raise a crop of cotton without any rain on the plants would seem an impossibility in many humid regions, but this can often be done in dry regions if the previous rainfall has been conserved in the soil by proper tillage. Indeed, it is possible to have too much water stored in the soil and thus make the plants too luxuriant, just as it is possible to have too much rain. Under such conditions there is the less reason to urge the importance of very early planting. In experiments with successive plantings of Triumph cotton at San Antonio, Tex., in 1906, the April and May plantings grew quite as large as the March plantings, showing a practical equality of the available supply of soil moisture, which was the limiting factor in this experiment. The surface of the soil be- comes drier as the season advances, so that recourse to previous wetting of the seed or to somewhat deeper planting may become necessary to secure a good stand, but the easier cultivation and greater freedom from weeds in dry weather more than compensate for extra precautions in sowing. LATER PLANTING IN BLOWING SOILS. In addition to the loss of moisture and the checking of the plants by weather too cold for growth to be made, early planting increases the danger of the “blowing out” of the seedlings in some of the sandy districts of southern Texas that are otherwise well adapted for cotton. The surface soil may be drifted away and the plants broken down by the wind or the young stems may be actually cut away by the blowing sand. The winds are said to be much more severe as a rule in March than in April, and in districts where this is true it might be better if all plantings could be deferred till the later month. Even though the winds were as severe in April as in March the crop is less likely to be injured if the period of exposure is shortened. It is also easier to keep the soil from blowing before the cotton is planted, by throwing the surface of the field into ridges. In addition to the possibility of avoiding injury from the wind, the April plantings are likely to have the advantage of more continu- ous growth. This not only favors an earlier and larger crop, as already explained, but tends at the same time to increase the length and the uniformity of the lint. The proportion of aberrant plants that are likely to appear in a variety of cotton depends to a 220 LIMITATIONS OF LATE PLANTING. 15 considerable extent upon whether the plants are severely checked in the early stages of development or make uninterrupted growth. LIMITATIONS OF LATE PLANTING. If whole communities could be organized so that all the cotton could be planted at the same time and all the plants destroyed in the fall, so that none would survive the winter, later planting would become more feasible than at present; but other interests of the crop forbid very late planting. In the northern districts of the cotton belt it is not safe to shorten the season by deferred planting, and even in places where the season is long enough the habits of the cotton plant set limits to late plant- ing. If the weather is too hot during the early stages, the fertility of the plants suffers through a change in the habits of growth. Fruit- ing branches are not produced so near the ground as in earlier plant- ings, but are replaced by more numerous upright vegetative branches. With plenty of moisture such plants become large and bushy and produce a late crop, at the mercy of the weevils. Or if dry weather cuts off the supply of moisture the growth of the late plants is checked before the fruiting stage is reached, so that little or no crop can be set. Under conditions of drought, the tendency to excessive vegetative growth of the young plants may be restricted by lack of water in the surface soil. This is another reason why late plantings are more likely to be successful in seasons when the drought is severe enough to check the multiplication of weevils. Thus at Palestine, Tex., in the season of 1909, some fields of cotton planted in June, after the har- vesting of a crop of potatoes, developed normally and gave larger yields than neighboring fields planted much earlier, in April or May. In a wet season such late plantings might be a complete failure. The fruiting stage would probably not be reached until the weevils had time to multiply and destroy the whole crop. Varieties differ in the readiness with which their characters are changed in response to differences of cultural conditions, some being more suitable for late planting than others. The tendency to deferred fruiting and to the production of excessive numbers of vegetative branches is still stronger in the Egyptian cotton than in the Upland series of varieties. Early planting of Egyptian cotton has been found necessary in Arizona as a means of controlling the growth of the plants, though no weevils exist. Planting too late also interferes with the early destruction of the stalks, a most desirable measure for reducing the number of weevils that survive the winter. The earlier this work can be done the more successful it is likely to be, for the principal object is to deprive the 220 16 RELATION OF DROUGHT TO WEEVIL RESISTANCE IN COTTON. weevils as early as possible of food and of facilities for breeding. If this work is postponed until the plants are killed by frost, much of the advantage of removing the stalks is lost, though it may still be very important to destroy the unripe bolls, which sometimes carry many weevil larve through the winter. In some districts the pastur- ing of the cotton fields in the fall is very useful, for the cattle eat the buds and green bolls with the weevils and larve that might otherwise be left in the fields. Another factor that tends to limit late planting in Texas is the prevalence of root-rot. As the attacks of this disease are often deferred till the latter part of the season, the plants that are killed may not represent a total loss. Some of their bolls may be ripe before the plants are killed, and the remainder are opened prema- turely by drying, so that the lint, though often weak and worthless, can be picked and sold with the rest of the crop. In some parts of Texas fields are often seen with half the plants dead from root-rot before the middle of September, though half or three-quarters of the crop may be already mature. If the crop were to be deferred by iate planting, root-rot injuries might involve a total loss. In such cases the root-rot, rather than the boll weevil, may be said to deter- mine the necessity for early planting. RELATION OF DROUGHT TO WEEVIL-RESISTANT HABITS OF GROWTH. Recognition of the importance of dry weather brings a new factor into the question of weevil-resistant habits of growth. If it be con- sidered a matter of first importance to lessen the number of weevils that go into hibernation in the autumn, it appears to be essential to use the earliest and most determined varieties, so that the crop can be completed at the earliest possible date, and thus leave the weevils without opportunity to breed for as long a period as possible before winter. It happens, however, that some of the best of the early varieties, such as the Triumph cotton of Texas and the Kekchi cotton of Guatemala, have low, compact habits of growth that undoubtedly tend to interfere with the beneficial effects of dry weather in killing the weevil larve. Fallen squares are much more effectively shaded by a low, compact plant than by one that bears its foliage farther up so that all of the ground under the plant is exposed directly to the sun during at least a part of the day. Plants that stand well up from the ground and allow the sun to reach and dry out the fallen squares and kill the weevil larve are able to secure in this way a dis- tinct advantage over the low, compact plants that shade the fallen squares and protect them from the dry winds. Many of the experimental plats at San Antonio in 1909 consisted of Triumph cotton. The low, compact form of the plants was well 220 RELATION OF DROUGHT TO HABITS OF GROWTH. 17 calculated to shade fallen buds lying under them, though even in such buds the weevils did not appear to prosper under conditions of very extreme drought. But an adjacent planting of a newly acclimatized Mexican type of Upland cotton gave much less shelter for the weevils. No leafy branches were developed at the base of these plants until after fruiting had begun, so that the early foliage was borne well up from the ground. This Mexican variety had not been supposed to have any special- ized weevil-resisting characters, although it had given very favorable results under weevil conditions. The contrast in behavior between this variety and the Triumph was very striking, the Mexican cotton having much less tendency to put out branches from the lower joints of the stem. Partly as a result of later planting and partly because of its different habits of growth, this cotton continued to develop slowly during the dry weather of May and June and was ready when rain finally came in July to put on very quickly a good crop of bolls. The tendency to ripen all of the bolls at one time has been shown in several other experiments and is to be reckoned as a very desirable characteristic of this type of cotton. It lessens the labor of picking and allows the fields to be cleaned of the old stalks early in the fall. The behavior of this Mexican type of cotton may be contrasted in many ways with that of the Kekchi cotton from Guatemala. The Kekchi cotton has several definite weevil-resisting adaptations not possessed by the Mexican cotton, such as hairy stems and leaves that restrict the movements of the weevils, large, hairy, well-closed bracts that impede the access of the weevils to the young buds, and long pendent or creeping basal branches, the buds and bolls of which are seldom attacked because of the strong instinct of the weevils to climb up the plants instead of remaining on the lower branches or crawling downward. But in southern Texas, where most of the experiments with cotton have been made, some of the weevil-resisting characters have cultural disadvantages. Although the lower branches often continue to produce buds and bolls long after the weevils have halted all the other types of cotton, the additional bolls are borne so near the ground that they are often soiled by blowing sand or muddied and rotted by rain. Bolls produced underneath the plant often rest on the ground and are also subject to mildew and other diseases. An attempt is being made to avoid these disadvantages by selecting more erect forms of the Kekchi cotton that carry their bolls clear from the ground and thus enable the several desirable features of this type of cotton to be utilized. In addition to the weevil-resist- ing characters, some of the acclimatized strains of the Kekchi cotton have shown themselves very early and productive, and with lint of good Upland quality. 18 RELATION OF DROUGHT TO WEEVIL RESISTANCE IN COTTON, It is easy to understand that a variety with a rapid-fruiting habit like the Mexican cotton would be even more likely to have definitely determinate growth than an early-flowering variety like the Kekchi. The small size of the plants of early varieties may be ascribed to the fact that vegetative growth is less rapid after fruiting commences and if dry weather ensues an extra early variety may mature and cease to grow even under the same conditions that permit another variety with later fruiting habits to continue its development. Determinate habits of growth, like other desirable things, may be carried to excess. If selection for earliness be directed solely to the question of early flowering or early opening of bolls the effect on yield may be adverse. Very early flowering or very early opening of some of the bolis is not in itself a guarantee of the practical weevil- resisting value of a variety. Varieties that flower very early may develop more slowly or attain a precocious maturity if exposed to dry weather or to other unfavorable conditions that interrupt the growth of the plants. IMPORTANCE OF DRY WEATHER IN HUMID REGIONS. In cooler and more humid regions the importance of the drought factor must of necessity decline. Unless the weather is hot and dry enough to interfere with the propagation of the weevil larve, the direct advantage secured from drought in a dry climate is not obtained. A humid climate with heavy dews may allow unimpeded development of weevils, even in the absence of rain. Yet there is 2 very important indirect advantage in a period of dry weather, even though the conditions are not severe enough to destroy the weevils. Too much moisture interferes with the development of the cotton plant, either by stunting its growth or by causing the shedding of buds and young bolls. In a district where there are no weevils such a shedding may do little damage, for the plants continue to produce buds and can soon replace the loss, but with the weevils present the loss of the early crop by shedding becomes a much more serious matter. Tn a continuously humid climate the early buds must be expected to furnish the crop, for all the later buds are likely to be destroyed by the weevils. There must be no delay in the development of the cotton if a crop is to be set before the insects become destructively numerous. The closer the race becomes between the cotton and the weevils, the more important it is that the plants lose no time in development and that the crop receive no setback by the shedding of buds or bolls. Every precaution that favors the quickest possible development becomes worthy of careful consideration, such as the planting of the cotton in dry, well-drained soil, thorough preparation and cultivation, and the application of fertilizers. 220 TYPES OF EARLINESS IN RELATION TO WEEVIL RESISPANCE. 19 One limitation must be recognized in all such efforts. It is possible in some regions to stimulate the cotton into an excessive vegetative growth, and thus defeat the object of securing an early crop. If the plants make too rank a growth at first, fruiting is likely to be de- ferred, the lower fruiting branches being replaced by vegetative limbs.? DIFFERENT TYPES OF EARLINESS IN RELATION TO WEEVIL RESISTANCE. The ideal form of earliness for varieties that are to be grown in humid regions is not extreme precocity in showing the first flowers or the first ripe bolls, but the production of the crop as rapidly as possible after fruiting begins. Even the early varieties are not so early in humid regions as in dry, for abundance of moisture con- duces to more vigorous vegetative growth and to the production of vegetative limbs near the base of the plant instead of fruiting branches. In a continuously humid region an early-fruiting variety would have no advantage over one that began to fruit a little later unless the later variety were attacked by weevils bred on the early variety, in case both were planted in the same locality. If all the cotton in a humid district began to bud and blossom somewhat later but had the rapid-fruiting habit, it would have two advantages over an early-fruiting variety in relation to the weevils. A smaller number of weevils would survive until the late variety began to fruit and the late variety would be able to set the same amount of crop in a shorter period, after it had once begun to fruit. Late varieties that differ from early varieties in completing a larger amount of vegetative growth before they begin to fruit should be able to produce fruit more rapidly after fruiting has once begun. Rapid fruiting, rather than early flowering or early opening of bolls, represents the most effective form of weevil resistance under conditions of continuous humidity. Other things being equal, there is more reason to expect fruiting to go on rapidly in varieties that begin to bud and flower rather late than in those that flower very early. A variety that begins to flower very early is likely to require more time to produce the same number of bolls than a later flowering variety. The relatively small size of the plants of all the early- flowering types may be taken as evidence that the very early produc- tion of fruit tends to check vegetative growth. In other words, earlier flowering may lead to slower fruiting, if account be taken of the total number of bolls or the quantity of cotton ripened within a given period. 1See “ Dimorphic Branches in Tropical Crop Plants,’’ Bulletin 198, Bureau of Plant Industry, U. S. Dept. of Agriculture, 1911. 220 290 RELATION OF DROUGHT TO WEEVIL RESISTANCE IN COTTON. A later date in flowering is not to be reckoned as a lessening of weevil resistance if a variety sets its fruits with sufficient rapidity after flowering has begun. Until the flower buds are about half grown the weevils can not begin to reproduce. The rapidity with which bolls are developed within a specified time after the buds are large enough to allow the weevils to begin to breed would serve as a measure of weevil resistance in experiments with varieties in humid regions. It is important to establish such standards and to apply them to all varieties that are to be grown under weevil conditions, whether the weevils are already present or not. In attempting to determine the rate of setting of the crop in dif- ferent varieties, special precautions must be used. It is not sufficient to compare the yield in early pickings, for this will give an undue advantage to the factor of early opening in small-bolled varieties. Neither is it sufficient to determine the tendency to fruit production by the daily counting of flowers on experimental rows or plats repre- senting the different varieties. Allowance must be made for the fact that a big-boll variety does not need to produce as many flowers in order to set the same amount of crop in the same number of days as a small-boll variety. Daily countings of the numbers of flowers on adjacent rows of different varieties may also be rendered unreliable by differences in shedding, some varieties dropping their buds and young bolls much more readily than others. The counting of the full-grown bolls at different dates would give an indication of the crop-setting habits if there were any ready means of determining when the bolls have reached full size. For the most accurate determination it would be desirable to make counts of the bolls as fast as they became large enough to escape weevil injury, though it would still be necessary to take into account the differing amounts of cotton represented by the same numbers of bolls of different varieties. It may be that the rapidity with which the bolls are opened cor- responds to that with which they are set, but there is no definite information on this point. It has been noticed in some plantings of Mexican cotton that the bolls seemed to open more nearly together than those of the Triumph cotton and other United States Upland varieties grown in the same places. The rate of opening of the bolls depends very largely on the weather at the time when the bolls reach maturity, but these experiments were made under dry condi- tions, with equal opportunities for opening. It was generally assumed at first that small-boll varieties must have a distinct advantage in weevil resistance because of earlier flowering and earlier opening of the bolls. Large importations of seed of the King and other small-boll varieties from the Carolinas were brought in to replace the Texas big-boll sorts in weevil-infested 220 IMPORTANCE OF RECOGNIZING FACTORS OF WEEVIL RESISTANCE. Q1 districts. Nevertheless, the small-boll cottons have not gained any general popularity in Texas, most farmers having returned to the native big-boll varieties. Additional familiarity with the factors that determine production under weevil conditions makes it pos- sible to understand why the big-boll varieties do not show any such serious disadvantage in weevil resistance as at first expected. The larger bolls require longer periods for full development, but during most of the time they are beyond the danger of weevil in- jury. The growth of the bolls continues longer after the crucial stage of weevil infestation has been reached. A big-boll variety that could produce as many flowers and set as many bolls in the same number of days as a small-boll variety could yield a larger crop in proportion to the increased size of the bolls, or larger bolls may make up for a deficiency in the number of flowers. The few ob- servations that have been made de not indicate that big-boll varieties fall very seriously below the small-boll sorts in their rates of flower- ing and boll setting. The production of flowers and young bolls may not make larger demands on a big-boll variety than on a small- boll type. If the weevils are to prevent any further boll setting after a certain date, a big-boll variety has the advantage of being able to produce more cotton in each of the bolls that reaches maturity. In districts where the season of growth is very short, early open- ing of the bolls may be necessary to avoid the danger of frost, but in a large part of the cotton belt the lapse of a few more days before the bolls begin to open is not to be considered as a serious disadvantage and is not likely to outweigh the stormproof quali- ties, easier picking, and other desirable features of the big-boll varieties. It is quite possible that the Texas big-boll type of cotton may be found less satisfactory in humid regions and that special selection may be necessary under the new conditions to establish local strains with uniform expression of earliness and other desir- able characters. In the drier regions of central and southern Texas, where the growth of the plants is usually limited by drought, the same general tendency to early fruiting appears in the big-boll and small-boll types, but greater differences may be shown where more abundant moisture provides for more luxuriant growth. IMPORTANCE OF RECOGNIZING FACTORS OF WEEVIL RESISTANCE. Too much stress can be laid upon early varieties as well as upon early planting, beeause both these factors lose in effectiveness if pushed to extremes. Cotton planted too early may develop more slowly than cotton planted later, and varieties that begin fruiting too soon may take longer to develop a full crop. These considera- tions are well-nigh self-evident when once pointed out, especially when viewed in relation to the dry-weather factor. If the benefits 220 22 RELATION OF DROUGHT TO WEEVIL RESISTANCE IN COTTON. exerted by dry weather are ascribed to early planting alone there is danger that the farmer may rely too much upon the date of planting and fail to appreciate the still greater importance of tillage and other means for securing an uninterrupted development of the crop. That the production of cotton has been maintained in Texas has been taken generally to mean that the weevil menace was exaggerated. This may be true to the extent that the susceptibilityof the insect to dry weather was not at first appreciated. In some localities the first seasons of weevil infestation were unusually wet. The destruction wrought by the weevils in the wet seasons was expected to continue every year, and the very existence of the cotton industry seemed to be threatened. At present the tendency is rather to the other ex- treme of optimism, on the assumption that the same results are to be expected over the whole cotton belt as in Texas. Such reasoning may prove erroneous, especially in regions that are subject to con- tinued rain or damp weather in the early part of the growing season. Continued wet weather is always unfavorable to the cotton crop, no matter how satisfactory the other conditions may be. The losses occasioned by wet weather become the more serious if weevils are present to prevent the setting of any later crop of bolls. In many cotton-growing districts the soils are so heavy and ad- hesive that the fields can hardly be entered for two or three days after each rain. In localities where the soils are varied much can be gained by choosing the driest and best drained land for cotton, but rain may still interfere with the cultivation of the fields and prevent the gathering of the weevil-infested squares. Even in places where good yields can be obtained in favorable sea- sons the growing of cotton may become unpopular if the crop be- comes too precarious. In the more humid sections of the coast belt of Texas, for example, some of the most progressive farmers con- sider the future of cotton culture as doubtful. Those who have been careful to clear their fields and destroy their stalks early in the fall and give their land good preparation and tillage have found it pos- sible to raise good crops of cotton in spite of the weevils. In other seasons, when too much rain interfered with cultivation and the plants grew too large and shaded the ground before the bolls were set, the crop was seriously reduced or became a total loss. Neverthe- less, the prevailing high prices have encouraged the taking of larger chances on the cotton crop, even by farmers who previously declared their intention of abandoning cotton altogether. « EARLIER LONG-STAPLE VARIETIES. The practical questions of weevil resistance vary in different re- gions, like other cultural problems. In the Texas short-staple dis- tricts an immediate advantage was obtained by the use of earlier 220 EARLIER LONG-STAPLE VARIETIES. 23 short-staple varieties. In long-staple districts the need of earlier varieties is still more acute. The introduction of the early short- staple varieties into the long-staple districts is not calculated to pre- serve the long-staple industry. There can be little doubt that the difficulty of producing the long staples is increased by the growing of the short-staple varieties in the same neighborhood. More weevils are bred early in the season in the short-staple fields. There is also more danger of admixture of the long-staple with the short-staple varieties, either by cross-fertilization in the fields or by the mixing of seed at the public gins. Even before the weevils came, the manufacturers complained that the long-staple varieties were deteriorating, because the fiber was be- coming less uniform. This has been ascribed to the fact that more and more of the ginning has been done in recent years at large pub- lic gins where the seed of the whole community becomes mixed, in- stead of at the smaller private plantation gins which gave much less opportunity for such admixture. If the long-staple varieties con- tinue to decline in uniformity at the same time that the yield is being cut down by the presence of the weevils, there is less prospect of an ultimate survival of the long-staple industry. The need of quick-fruiting long-staple varieties has been recog- nized in advance in the cotton-breeding work of the Department of Agriculture. Two such varieties have been developed and distrib- uted, the Columbia cotton, originated by Dr. H. J. Webber, in South Carolina, and the Foster cotton, bred by Dr. D. A. Saunders for the Red River Valley of Louisiana and northeastern Texas. These varie- ties are not only distinctly earlier, but are also more productive than the older long-staple sorts. In their habits of growth they are much more similar to short-staple Upland varieties and they seem to yield at least equally well. Some of the Columbia cotton raised in the sea- son of 1910 has been reported as selling as high as 24 cents a pound. While this price may be considered exceptional, there can be no doubt that a very general increase in the value of the cotton crop could be secured by replacing the present short and variable stocks with such varieties as the Columbia and the Foster. The early-maturing characteristics of these varieties give them almost the same advantages of weevil resistance as the early short- staple varieties that are now being grown in former long-staple dis- tricts. The chief difference is that prolonged drought is a greater danger to the long-staple crop than to short staples. The difference is not so much in the ability of the plants to withstand dry weather as in the requirement of continuous growth, if uniform length and strength of fiber are to be secured. If the growth of the plants be checked during the fruiting season, shorter and weaker fiber is the result and the whole crop is injured by the lack of uniformity. The 220 24 RELATION OF DROUGHT TO WEEVIL RESISTANCE IN COTTON, higher requirement of uniformity limits the production of long- staple cotton to districts where the soil moisture is adequate or is supplemented by irrigation. The irrigation facilities being devel- oped in many localities in southern Texas may make it possible to extend the cultivation of long-staple varieties to a new region. It remains to be seen whether cotton-growing communities can be organized to take full advantage of early long-staple varieties that have been developed. The size of the crop and the uniformity of the product may both be increased if whole communities, instead of scattered individual planters, can devote their time to the production of long-staple varieties. The preservation of the necessary uni- formity of the long-staple varieties will become much easier if no short-staple types of cotton are grown in long-staple communities. The deterioration of varieties through cross-fertilization in the field and by the mixing of seed at gins can both be avoided in well- organized communities that limit themselves to one superior variety of cotton. DIFFICULTY OF DIRECT TESTS OF WEEVIL RESISTANCE. One of the chief obstacles in the study and general application of the factors of weevil resistance lies in the great difficulty of making any comparative tests that will definitely determine the actual values even of factors that have obvious practical importance. It is not reasonable to disregard these factors because of the difficulties of testing them. Fortunately there is no possible conflict between the cultural methods that are advised for purposes-of weevil resistance and those that are calculated to secure maximum production, even without weevils. In the case of early and late varieties the planting of the two side by side is likely to give an exaggerated idea of the benefits of earli- ness. It is certainly to be expected that a row of late cotton will suffer much more by being planted next to an early row infested with weevils than if there were no early cotton in the neighborhood. But if the plantings are made in separate fields to avoid the danger of weevils from adjacent rows, the equality of other experimental con- ditions can not be assured. Differences of yields at the end of the season can not be ascribed with any confidence to weevil differences alone. The soil may differ in fertility or in the content of moisture and cause wide fluctuations of the crop, even in regions that have no weevils. All other considerations are likely to be overshadowed and forgotton when the weevils are at hand. Nor does the use of isolated fields give any assurance of equality in the numbers of weevils. Even in parts of the same field the extent of damage from weevils usually shows wide variations, often 50 per cent and upward, especially in 220 CONCLUSIONS. 95 the early parts of the season before the period of total infestation is reached. The planting of the two kinds of cotton side by side insures unfair conditions for the late cotton by breeding an extra supply of weevils close at hand. But if the experiment is made in isolated fields the usual inequalities of infestation may give an unfair advantage to either planting. A field of late cotton planted by itself might appear at no such disadvantage in relation to weevil injury as would be expected from experiments with early and late rows planted close together. As a matter of fact, it often happens that a late-planted field suffers less from the weevils than fields a mile or two away that were planted a month or six weeks earlier. But as soon as we begin to compare the different fields more in detail it becomes apparent that many other elements may modify our conclusions. More fertile soil or more favorable temperatures that enable the plants to make more rapid and uninterrupted growth may be the cause of a larger yield, instead of any particular factor of weevil resistance that might have been under investigation and that might have very definite importance in another case. In short, the problem of weevil resistance is not to be separated from other complex cultural problems. The factors of weevil resistance have to be studied and applied from the standpoint of the local conditions that determine the choice of varieties and methods of cultivation. CONCLUSIONS. The presence of the boll weevil introduces another factor of un- certainty into problems of cotton production in addition to the usual differences of soils and seasons. The effects of special methods of cul- ture and the special characteristics of varieties should be taken into account in attempting to grow cotton in weevil-infested regions. Weevil-resisting characters and methods of cultivation are more useful in dry regions or in dry seasons, because the propagation of the weevils is less rapid and the weevil-resisting factors are effective for longer periods. In dry regions the same factor that restricts the growth of the plants also tends to prevent the propagation of the weevils. In humid regions, on the other hand, the growth of the plants may be impeded by wet or cloudy weather that does not restrict the propagation of the weevils. Wet weather not only favors the rapid multiplication of the wee- vils, but also interferes with the application of cultural expedients for avoiding weevil injury. Even the weevil-resistant characters of earli- ness, quick fruiting, and determinate habits of growth are likely to 220 26 RELATION OF DROUGHT TO WEEVIL RESISTANCE IN COTTON. diminish or to disappear when the plants are grown under extreme conditions of heat and humidity. Smaller injuries from weevils lend a relative advantage in dry regions and in dry seasons. It is not safe to assume that improved cultural methods, earliness of varieties, or special weevil-resisting characters will have the same value in humid regions that they may have shown in dry seasons in Texas. In the absence of the limiting factor of drought, it is not safe to apply the analogies drawn from Texas to the more eastern States. The problem of weevil resistance is especially acute in the humid bottom lands of Louisiana and Mississippi, the chief centers of pro- duction of the long-staple Upland varieties. Every possibility of weevil resistance in the long-staple district is worthy of careful in- vestigation, because special conditions of soil and climate make it possible to produce superior grades not generally obtainable in other parts of the cotton belt. Earlier maturing long-staple varieties that have been bred in the United States or acclimatized from abroad may replace the present long-staple varieties whose late-maturing habits render them more susceptible to injury by the boll weevil, especially when grown in the same localities with early short-staple varieties. Two additional measures of weevil resistance are also worthy of careful consideration in humid regions, the development of quick- fruiting long-staple varieties and the better organization of cotton- growing communities so that only one type of cotton shall be grown in the same locality. While the use of early-fruiting varieties and the early planting of the crop are important in avoiding weevil injuries, both of these policies have distinct limitations. Very early varieties may be rela- tively unproductive, and too early planting may check the growth of the seedlings, delay their development, and postpone the fruiting period. The chief object is to secure the most rapid setting of a good crop rather than the earliest opening of flowers or bolls. The early production of flowers or of ripe bolls does not prove that a variety has the most effective form of earliness for purposes of weevil resistance, especially if this precocious fruiting tends to re- strict the growth of the plant. Rapidity of fruiting after fruiting has once commenced is more important than absolute earliness, as shown by the dates of the first flowers or the first open bolls. The setting of a crop of bolls in the shortest time after the flower buds begin to appear is the ideal form of earliness from the standpoint of weevil resistance. This requirement of rapid fruiting should be taken into account in the breeding of weevil-resistant varieties, as well as in devising improved methods of culture for weevil-infested regions. 220 CONCLUSIONS. 27 As the weevils are restricted for food to the pollen of the cotton plant and are unable to begin to breed until the production of flower buds has begun, breeders of new varieties for weevil conditions should consider that plants may gain rather than lose if the forma- tion of fruit buds can be deferred till the roots and other vegetative parts have made considerable progress, especially if this preliminary growth allows the more rapid formation of fruit buds when fruiting has once commenced. Though later flowering varieties might appear to suffer more from the weevils than the early-flowering varieties if the two were planted side by side, the true agricultural value of a late-flowering variety would not be settled by such an experiment. It is obvious that some- what later flowering would not be a disadvantage if it shortened the period of setting the crop. Nor would a somewhat later opening of the first bolls be undesirable, especially if there were a tendency for the whole crop to open more nearly together. The practical value of rapid-fruiting long-staple varieties would also be increased if they were planted by whole communities. The exclusion of earlier short-staple varieties might be expected to give the long-staple varieties less exposure to weevil injuries, and at the same time it would help to maintain the uniformity of the crop by avoiding cross-pollination by bees and admixture of seed in public gins. 220 ah ah wm a ons fendi a adr cote ata: e coer rgd pleura > bebeled foewedl 6] tied wo Pa ce artvertdhter: (tive: ol) comererrh Won! hy v iran ala Diese) and) seller idbciyy’ unt cihtepalaleed 4) Liatelywnemiitkei ae cinot of f ligetebpral oly of emeby Tranctibriq alin bniosue saeiQueta wind Lae anti) ania abo tdind ) oodiieamon) beg wignD > r 4 ywreenul t 4 F . Yeee Hay preeahaeso01i owns celery Td wen esttielret mar i wool) te é Adie seperate ors cee one totter aw br re ered eye as elt nae piney ‘end whlLemh et eéal Wo hhwn nine re oe geil atvade pil» Soletedgke ik the ya Die paid tnivest wie oy rade b A eck wap ihyaw yt ay ‘ act haie(n “tote ier! Serie dl LG ago Vo" os an} Rods Wideoliretr giereay se prorts 8 | i aeiote) ofetpertes i a ae ‘ on? Vitae som mada oF an ge: (549 oh e@-qnae)) nimi so entay' ‘ioe. 4 7 ia) f 1 ass elem Nive | pet) eb hoy yah; a eitha Prone el! Pricer ci heretae! Wie Srp aitek me 56° 2 eed Pi Vy “ey eee » eaat gl Tare? car wes 2 OTIC wie Sih tard er (Ve Ht y td, lel eesoe i; ime fi te wiwevienbe bee wel Ganon 6 q f = Aye P Oil dtd oe INDEX. Page. Arizona, Egyptian cotton, early planting to control growth.............--.--- 15 Bees siactor an cross-pollination of cottom..---..-=.........s0te8ssc2 Jee 23, 24, 27 ‘*Black-land”’ prairies of Texas. See Texas, ‘‘black-land’’ prairies. Cessation of weevil injuries. See Weeyvils. Columbia cotton. See Cotton, Columbia. Communities, organization for culture of cotton.........-....-.---- 10, 15, 24, 26, 27 een Menrecm NMMeLIN 2. oss: eet cae ch oh 3282... edie ala 25-27 Cotton, big boll, comparison with small-boll varieties.............-...------ 20-21 menminbia, origin and characteristics. +... - -2.= si =--<5d-8< 20 3.ces .528 23 cultural methods as related to weevil resistance. .--_--- 8, 10-12, 13-16, 25-26 Me TOWNS SOUS... <5 oo. os 5.3 eeei as 2a eed - sh! 14-15 GRY PEPIONS © a2 aS ree ao ot at ce See ees 7, 10-12, 25-26 UIT CET EOL OTA aN es eS ode ot een 18-19, 25-26 Texas. See Texas, cotton culture. MaaeteMon Of sidlks in autumMmnss-\< J.425- 2422s oot = ste 2 15, 16, 17 Berar IOM OF CATINCSS < 31-2242) baci. + ees boas tee . eddies au 20 imeremuty PES Of CATINOSS . on 52 abet o 55 - salve sedape his ees 19-21, 26 Ppune aire OU WATIOLIOS 25 Sogo ow ttes 3a oe oes ees sees c cso. oo 20 Peete Cally PIANOS. 525 6 ose Gs a eee tt wD. ot eee Be eee 15 Paenmou ol culture to.driemrerions-- 2ace3- 2555556 sos ee 7,12, 24 FARLOIS\OLsWEeVIL TESISLANCE! = = 2. o< sc ow ence cezeeet ce. 7, 10, 21-22, 24-27 eee orinitt and Characteristics. o- <<. 730 seu 5caeea- 2 oe: ene 23 habits of growth, relation to weevil resistance. -......-.....-.---- 16-18, 23 wupenvement by cultural methods... 2... - sss +4-<6eedse-seecek 13-14 TEMG ae See ee eee eee a nr ree meee ns 12, 13-14 Sekelimenapits Ol oTOW UM. == .222 525 cemaete sesh eon bie See 16, 17,18 Pieremeteiied to, Lexds 225. 522. sno l te cpdsenhs'J-ki saenag- eee 20 limitations of late planting for weevil resistance....-.-...-.--.----- 15-16 long staple, cultural requirements -.-...-..-...-------.s:- 13-14, 22-24, 27 foaean type: Habits Of srowLh..~ -= 4-20...