THE UNIVERSITY OF ILLINOIS LIBRARY e_o-io. >O AGRICULTURAL IIBRARV UNIVERSITY OF ILLINOIS Agricultural Experiment Station BULLETIN No. 206 FIELD EXPERIMENTS IN SPRAYING APPLE ORCHARDS IN 1913 AND 1914 BY B. S. PICKETT O. S. WATKINS W. A. EUTH A. J. GUNDEESON URBANA, ILLINOIS, APRIL, 1918 CONTENTS OF BULLETIN No. 206 PAGE INTRODUCTION 429 SPRAYING EXPERIMENTS IN 1913 AT NEOGA, CUMBERLAND COUNTY 432 SPRAYING EXPERIMENTS IN 1914 AT NEOGA, CUMBERLAND COUNTY 441 SPRAYING EXPERIMENTS IN 1913 AT FLORA, CLAY COUNTY 449 SPRAYING EXPERIMENTS IN 1913 AT GRIGGSVILLE, PIKE COUNTY 458 SPRAYING EXPERIMENTS IN 1914 AT GRIGGSVILLE, PIKE COUNTY 472 GENERAL SUMMARY SUMMARY OF DATA 490 INCIDENTAL OBSERVATIONS 504 RECOMMENDATIONS .. . 505 FIELD EXPERIMENTS IN SPRAYING APPLE ORCHARDS IN 1913 AND 1914 INTRODUCTION BY B. S. PICKETT, ASSISTANT CHIEF IN POMOLOGY OBJECTS OF FIELD EXPERIMENTS IN SPRAYING APPLE ORCHARDS IN 1913 AND 1914 In view of the exhaustive investigations already made by the De- partment of Horticulture in spraying for the control of insects and diseases attacking the apple,1 it seems advisable to explain the neces- sity for further experiments in spraying. No single operation in apple growing yields such immediate and large returns for the money and time invested as spraying. In fact, it is a rare season in Illinois when unsprayed apples are marketable, except for cider and evaporating purposes. The extreme importance of the operation, in itself, is therefore sufficient cause for unremitting experimental efforts to make it more and more effective and less and less costly. New sprays are constantly being placed on the market, by enterprising firms dealing in spraying materials. New forms of standard insecticides and fungicides, whose merits and faults call for investigation, are introduced annually. Some of the effects of the standard sprays are not yet fully understood, as, for example, Bor- deaux russet, yellowing of the leaves following the use of Bordeaux, and lime-sulfur burn. The efficiency of the standard sprays varies in different seasons, and only the cumulative data of many years of ex- perimental work seem likely to afford records sufficient to permit a conclusive coordination between climatic conditions and the effects of the sprays. Methods of application, including amounts, pressures, character of agitation, and machinery, are not yet perfect; each sea- son's experiments show a need for further tests along these lines. The field experiments in spraying in 1913 and 1914 included fur- ther tests of the effectiveness and relative values of the standard sprays on the control of fungi and insects affecting the apple crop, of several makes and brands of arsenate of lead, certain new and proprietary fungicides, several methods of preparing and using copper ferro- cyanide, the effects of varying quantities, pressures, and nozzle open- ings, the use of Bordeaux for some applications and lime sulfur for the remaining applications in the spray schedule of the same season, the effects of certain special spray practices on the control of codling moth, and the efficiencies of various strengths of lime sulfur. irThe details of these investigations are contained in Bulletins 98, 106, 114, 117, 118, 135, and 185, and popularized in Circulars 112, 120, 136, 137, 159, 160, 171, and 172. 429 430 BULLETIN No. 206 [April, ORGANIZATION The experimental orchards were located at Neoga in Cumberland county, at Flora in Clay county, and at Griggsville in Pike county. O. S. Watkins conducted the experiments at Neoga, W. A. Ruth, those at Flora, and A. J. Gunderson, those at Griggsville. STANDARD SPRAYS: FORMULAS AND PREPARATION Except where noted in connection with the individual experiments, the Standard sprays used were prepared according to the following formulas and directions: Bordeaux. — Eight pounds copper sulfate, 8 pounds freshly slaked lump lime, 100 gallons water. The mixture was prepared by dissolv- ing the copper sulfate in half the total quantity of water used, and mixing the slaked lime with the other half. The diluted solution and the diluted mixture of lime were then poured simultaneously thru a sieve, either into the mixing tank or directly into the spray tank. Lime Sulfur, Commercial, for Summer Sprays. — Eight pounds of sulfur in 100 gallons of spray (3 gallons commercial concentrated lime sulfur to 97 gallons of water, or 3 gallons commercial concen- trated lime sulfur in 100 gallons of the dilute summer spray). Lime Sulfur, Commercial, for Dormant Spray. — Twenty-nine to 30 pounds of sulfur in 100 gallons of spray (11 gallons commercial concentrated lime sulfur to 89 gallons of water, or 11 gallons commer- cial concentrated lime sulfur in 100 gallons of spray). Lime Sulfur, Homemade, for Summer Sprays. — Eight pounds of sulfur in 100 gallons of spray (5^ gallons stock solution homemade lime sulfur to 941/*) gallons of water, or 5^ gallons stock solution home- made lime sulfur in 100 gallons of spray). Lime Sulfur, Homemade, for Dormant Spray. — Twenty-nine pounds of sulfur in 100 gallons of spray (20 gallons stock solution homemade lime sulfur to 80 gallons of water, or 20 gallons stock solu- tion homemade lime sulfur in 100 gallons of spray). Stock Solution, Homemade Lime Sulfur. — One hundred pounds of salfur, 50 pounds of lime, water to make 66 gallons.1 Homemade lime sulfur was prepared by placing in a large kettle 15 gallons of water and 50 pounds of good lime, free from air-slaked particles. When the lime was slaking vigorously, 100 pounds of powdered sulfur was poured in and mixed thoroly with the lime. Sufficient water was added gradually to prevent the lime from drying out during the proc- ess of slaking. As soon as the lime was thoroly slaked and the sulfur thoroly mixed, enough water was added to bring the total volume to 66 gallons or a little more. Boiling was continued for 30 to 45 min- utes, water being added from time to time to keep the volume at 66 gallons. By following this method it was found possible to get the Illinois formula. 1918] SPRAYING APPLE ORCHARDS IN 1913 AND 1914 431 •maximum amount of sulfur into solution. The boiling was done in large iron kettles heated over simple outdoor fireplaces or in 75- gallon feed cookers. Arsenate of Lead. — Four pounds of paste arsenate of lead in 100 gallons of water, Bordeaux, or lime sulfur. The arsenate of lead was worked up with a small quantity of water into a mixture that would pour readily and mix evenly with the water or fungicide when sub- jected to the action of the agitator in the spray tank. TIMES OF APPLICATION The various applications are designated as follows: dormant-tree spray, first, second, third, and fourth summer sprays, and extra sprays. The dormant-tree, or winter, spray is applied between the falling of the leaves in autumn and the swelling of the buds in spring. Its primary function is the destruction of scale insects. The first sum- mer spray is applied between the bursting of the cluster buds and the opening of the blossom buds. The application of the second summer spray is begun as soon as most of the petals have fallen. It is followed in about ten days by the third application. The time of the later applications varies, depending on the purposes for which they are given. The exact dates of the applications in these experiments are given with each report. RECORDS The records of these experiments include data of insect and fun- gous attacks on both fruit and foliage and of the amount and char- acter of spray injury, percentages of the various grades of fruit, and observations of prevailing conditions of weather. Dropped apples were examined at intervals thruout the season, and at harvesting time both dropped and picked apples were examined for evidences of dis- ease and insect injury, the observations being tabulated for compara- tive study. Frequent observations of the effectiveness of the sprays in controlling insects and fungi attacking the foliage, or of their be- ing in themselves the cause of injury, were also recorded. Weather observations were recorded in the form of daily maximum and mini- mum temperatures, temperatures at stated hours, rainfall, cloudiness, and direction of the wind. ARRANGEMENT OF SUBJECT MATTER The method of presenting the data obtained in the spraying ex- periments in 1913 and 1914 is similar to that used in Bulletin 185, which gives the data recorded during the years 1909-12. A yearly report is made by each experimenter, giving at length the plan of the experiment, conditions, methods, data, and summary of results. A general summary of all the results for the two years follows. Finally, a series of spraying recommendations is given. 432 BULLETIN No. 206 [April, SPRAYING EXPERIMENTS IN 1913 AT NEOGA, CUMBER- LAND COUNTY ' BY O. S. WATKINS, ASSOCIATE IN HORTICULTURAL CHEMISTRY OBJECTS The chief objects of the investigations at Neoga in 1913 were to determine (1) the comparative values of several brands of arsenate of lead, alone and in combination v/ith lime sulfur; (2) the value of a fourth summer spray for the control of second-brood codling moth; and (3) the relation of pressure to Bordeaux injury. LOCATION AND DESCRIPTION OF ORCHARD An orchard owned by H. A. Aldrich and Company and situated one-half mile west of the railroad station at Neoga was chosen for these experiments. The 120 acres comprizing the orchard were planted to several different .varieties of apples, thereby affording ideal pollinizing conditions. Since the planting of the orchard in 1900, it had received excellent care ; hence the trees were in a very healthy condition. Seven acres of Ben Davis trees and five acres of Jonathan trees were selected for experimental purposes. These tracts were di- vided into plats of four to ten trees each, the various plats being treated differently. Scattered among the plats were certain trees which were not sprayed, and which were reserved for comparison with the sprayed trees. The arrangement of the plats is shown in Fig. 1. APPARATUS AND MATERIALS The sprays were prepared according to the methods described on pages 430 and 431. They were applied with a Friend power outfit; unless otherwise stated, a pressure of about 135 pounds was used. A single Friend angle nozzle was used on the tower pole, and a Gould double Mistry, attached to an angle Y, was used on the ground pole. The brands of arsenate of lead tested were Corona dry, Vreeland powdered, and Grasselli, Hemingway, Sherwin-Williams, and Thorn- sen pastes. WEATHER CONDITIONS The weather conditions for 1913 were far from normal. Early in May a drouth began which continued until late in August. The combined rainfall of May, June, July, and the first three weeks in August was less than four inches, and at no time was there as much SPRAYING APPLE ORCHARDS IN 1913 AND 1914 433 OO«OO 000QQ ooaoo 00.000 OO'OOO OQPOO OQ-QOO 00,000 OQ-QOO OQ.OOO OQ-QOO oopoo OO'OOO oo.ooo' OO'OOO OOoOOO OO'OOO oopoo 'OOP )OOO 00000 OQOOO ooooo oopoo ooooo oopoo ooooo oopoo ooooo OQOOO ooopo ooooo o "9 O Sd cQ Q .C j cQ 434 BULLETIN No. 206 [April, as one-half inch in a single rain. The orchard was, therefore, in a very dry condition all summer. Even the spray pond was exhausted during the third application, and water for the remainder of this application and for all of the fourth was hauled from a well in town. On five days in June, eight days in July, seven days in August, and two days in September, the temperature exceeded 100° F. During this dry season no fungous diseases developed; hence the data col- lected relate chiefly to codling-moth injury. The trees came into bloom early in May. The bloom cf the Jona- than trees was very heavy, but that of the Ben Davis trees was light and scattering. The weather was excellent for pollination, and a very good set of fruit resulted wherever there was good bloom. SPRAY DATES The entire orchard was given a winter. application of lime sulfur early in April. Three or four summer applications were made upon or near the following dates : April 24, May 12, May 22, and July 8. TESTS OF VARIOUS BRANDS OF ARSENATE OF LEAD ALONE AND IN COMBINATION WITH LIME SULFUR These tests were made with the Ben Davis variety on plats of four to six trees each. The plats were treated as shown in Tables 1 and 2. In every case, applications were made on the same day and under conditions as nearly alike as possible. EFFECT ON FOLIAGE Little difference was noticed in the appearance of the foliage given the various treatments. As late as September it was impossible to distinguish the unsprayed trees from the sprayed, except by close in- spection. Where arsenate of lead alone was used, no spray injury of any kind appeared. Plat 28, sprayed with Vreeland powdered ar- senate of lead and lime sulfur, showed a small amount of leaf -burning shortly after the third application, but this resulted in no serious injury to the foliage. EFFECT ON FRUIT The fruit from the plats sprayed with arsenate of lead without a fungicide was picked October 14, with the results presented in Table 1. Less than half a crop was harvested; consequently the records ob- tained may not be considered entirely conclusive. A very severe in- festation of codling moth was present; in fact the unsprayed trees showed nearly 100-percent injury. In both the sprayed and the un- sprayed plats, the smaller the crop, the greater was the injury. In 1918] SPRAYING APPLE ORCHARDS IN 1913 AND 1914 435 the plat sprayed with Grasselli arsenate of lead, where less than a bushel of apples per tree was produced, the infestation was severe. The best control was shown in the plat sprayed with Sherwin-Williams arsenate of lead, where the trees yielded considerably more fruit. TABLE 1. — EFFECTS OF DIFFERENT ARSENATES OF LEAD USED ALONE, ON BEN DAVIS APPLES, IN THE EXPERIMENTS AT NEOGA, 1913 Plat Treatment Appli- ca- tions Picked apples Total No. Percentage affected by — Codling moth Russet Calyx Side Total 19 21 23 Check 4-100 Grasselli arsenate of lead 4-100 Sherwin-Williams arse- nate of lead 1,2,3 1,2,3 :1, 2, 3 •None 528 2310 2096 416 3 4 1 18 63 30 43 80 66 34 44 98 0 0 0 0 2-100 Corona ^dry arsenate of lead No treatment Most of the trees sprayed with the various arsenatcs of lead in combination with lime sulfur produced a half crop or more. This was picked October 14 ; the results of the examinations are shown in Table 2. The trees in these plats, like those sprayed with arsenate of lead alone, showed a large amount of codling-moth injury ; here, also, the degree of injury tended to vary with the yield of fruit. Plat 25, sprayed with 4-100 Corona dry arsenate of lead, and having the largest yield of fruit, showed the least injury from codling moth. Only one plat, that receiving Vreeland powdered arsenate of lead, showed any russet; 9 percent of the fruit from that plat was sufficiently russeted to be graded with the culls. TABLE 2. — EFFECTS OF DIFFERENT ARSENATES OF LEAD IN COMBINATION WITH LIME SULFUR, ON BEN DAVIS APPLES, IN THE EXPERIMENTS AT NEOGA, 1913 Plat Treatment Appli- ca- tions Picked apples Total No. Percentage affected by — • Codling moth Russet Calyx Side Total A, 24 25 26 27 28 Check 4-100 Grasselli arsenate of lead with lime sulfur 1, 2,3 1,2,3 1,2,3 1, 2, 3 1,2,3 1, 2, 3 None 1530' 2060 3571 1064 1800 2112 416 5 2 2 5 7 14 18 45. 49 38 56 56 50 80 50 51 40 61 63 64 98 0 0 0 0 0 9 0 2-100 Corona dry arsenate of lead with lime sulfur .... 4-100 Corona dry arsenate of lead with lime sulfur.. 4-100 Thomsen triplumbic ar- senate of lead with lime sulfur 4-100 Hemingway arsenate of lead with lime sulfur. . . . 2-100 Vreeland powdered ar- senate of lead with lime sulfur No treatment 436 •BULLETIN No. 206 [April, The results of this experiment, altho hardly consistent, somewhat favor the Grasselli paste and Corona dry arsenates of lead. VALUE OF A FOURTH SUMMER SPRAY FOR SECOND-BROOD CODLING MOTH It has been a question among growers whether the second-brood codling moth did sufficient injury to warrant a special application to prevent it. To determine the value of a fourth summer spray, applied early, in July, at the proper time to check the attacks of second-brood codling moth, two plats of Ben Davis trees were sprayed as shown in Table 3. Commercial lime sulfur und Grasselli arsenate of lead paste were used. In order to determine the effect of the spray upon an earlier ripen- ing variety, experiments were also conducted on Jonathan apples, which mature two or three weeks earlier than Ben Davis. Valuable results were secured, for the fruit of this variety was picked before a third brood, which appeared very late in the season, began to work. The treatments for the Jonathan plats are shown in Table 4. Each plat was divided into two sections of five trees each ; one section was sprayed three times and the other four times. EFFECT ON FOLIAGE No foliage injury of any kind appeared. On the Ben Davis trees the fourth application was visible thru the entire season. On the Jonathan plats, wherever Bordeaux arsenate of lead was used, the ?pray remained visible longer than where other sprays were applied. EFFECT ON FRUIT The Ben Davis plats produced a small crop, which was picked October 15, giving the results presented in Table 3. Here the benefits of the fourth application could not be determined, for a third brood of moths began infesting the apples early in October, upon which the application made in July exerted no influence. This late brood far outnumbered the first and second broods combined. TABLE 3. — EFFECTS OF SPRAYING FOR SECOND-BROOD CODLING MOTH, ON BEN DAVIS APPLES, IN THE EXPERIMENTS AT NEOGA, 1913 Plat Treatment Appli- ca- tions Picked apples Total No. Percentage affected by codling moth Calyx Side Total A, As Check Lime sulfur arsenate of lead 1, 2, 3 1,2,3,4 None 1530 822 416 1 18 45 50 80 50 53 98 Lime sulfur arsenate of lead No treatment 1918] SPRAYING APPLE ORCHARDS IN 1913 AND 1914 437 All the Jonathan plats produced a good crop. The fruit was picked September 23, and showed the results presented in Table 4. The fourth application reduced codling-moth infestation from 15 to 47 percent wherever used, thus demonstrating the effectiveness and value of this spray, especially for seasons like that of 1913, when the insect was present in such large numbers. In contrast to the Ben Davis plats, where the fruit was harvested after the appearance of a third brood, the fruit from the Jonathan plats showed the actual degree of control exercised by the sprays on the second brood. Quite a number of apples were cracked, probably as a result of rapid growth caused by the rains which fell just previous to the ripening of the fruit. TABLE 4. — EFFECTS OF SPRAYING FOR SECOND-BROOD CODLING MOTH, ON JONATHAN APPLES, IN THE EXPERIMENTS AT NEOGA, 1913 Plat Treatment Appli- ca- tions Picked apples Total No. Percentage affected by — Codling moth Crack- ing Calyx Side Total 4 Copper ferrocyanide arsenate of lead 1, 2. 3 4234 3 29 32 3 Copper ferrocyanide arsenate j ) ^ of lead 1, 2, 3, 4 2391 2 15 17 2 7 Lime sulfur arsenate of lead. . 7 7 ^) 1,2,3 3739 2 24 26 5 Lime sulfur arsenate of lead . . . 1,2,3,4 5067 3 14 17 3 8 Lime sulfur arsenate of lead.. 1, 2 Bordeaux arsenate of lead . . . 3 4050 2 25 27 " 4 Lime sulfur arsenate of lead. . 1, 2 Bordeaux arsenate of lead . . . 3, 4 4261 5 18 23 4 12 Bordeaux arsenate of lead. . 1,2,3 3474 7 27 34 12 Bordeaux arsenate of lead .... 1,2,3,4 5800 6 20 26 6 Check No treatment . . None 456 32 . 52 84 2 NOTE. — Four pounds of Grasselli arsenate of lead paste were added to each 100 gallons of spray. The copper ferrocyanide was made from 2 pounds of copper sulfate dissolved in 50 gallons of water, and 2 pounds of potassium ferrocyanide dis- solved in another 50 gallons of water, poured together simultaneously. Commercial lime sulfur and 8-8-100 Bordeaux were used. EFFECT OF PRESSURE ON BORDEAUX INJURY .In 1905 the Station began an investigation to determine the cause of injury following the 'use of Bordeaux. It had been noticed that whenever the material was applied with a hand outfit at a pressure of about 100 pounds, there was less injury than when it was applied with a power sprayer, which gave a higher pressure. To gain further information on this point, 8-8-4-100 Bordeaux arsenate of lead was applied to Jonathan trees at the pressures shown in Table 5. 438 BULLETIN No. 206 [April, EFFECT ON FOLIAGE * The trees sprayed with Bordeaux arsenate of lead at 125 pounds pressure developed no leaf-yellowing whatever. Those sprayed at a pressure higher than 125 pounds showed a small amount of this in- jury. In every case, the higher the pressure, the greater was the injury, altho in no plat was it serious. Heretofore Bordeaux injury had been accompanied by wet weather; this was not the case, how- ever, in 1913. EFFECT ON FRUIT The trees in these plats yielded a very heavy crop of fruit, which was picked September 24, with the results presented in Table 5. The point of greatest interest in this table is in the russet column. Bor- deaux applied at 125 pounds pressure caused no russeting whatever, while all pressures above that caused considerable injury. The ex- tremely high pressures caused no more injury than the 160-pound pressure. The loss of fruit due to cracking was also greater where the higher pressures were used. TABLE 5. — EFFECTS OF SPRAYING JONATHAN APPLES AT DIFFERENT PRESSURES WITH 8-8-4-100 BORDEAUX ARSENATE OF LEAD, IN THE EXPERIMENTS AT NEOGA, 1913 Plat Spray pressure Appli- ca- tions Picked apples Total No. Percentage affected by — Codling moth Rus- set Crack- ing Calyx Side Total 9 10 11 12 Check 160 Ibs. . 1,2,3 1,2,3,4 1,2,3 1,2,3,4 1, 2, 3 1,2,3,4 1,2,3 1,2,3,4 None 5192 6450 5939 5550 1007 3157 3474 5800 416 1 4 1 1 4 2 7 6 18 16 14 20 16 26 20 27 20 80 17 18 21 17 30 22 34 26 98 5 13 9 9 7 9 0 0 0 15 14 10 16 17 22 12 6 0 160 Ibs 190 Ibs. . 190 Ibs 225 Ibs.. . 225 Ibs : 125 Ibs 125 Ibs No treatment The question as to the necessity of using 200 pounds pressure in spraying for codling moth is apt to come up in this connection. These results show that 225 pounds pressure controlled codling moth very little more efficiently than 125 pounds. Interesting facts not shown in the table were brought to light by an examination of the dropped apples. Very little codling-moth injury appeared earlier than August 1, even upon the check trees. From August 1 until harvest time the number of drops injured by W18] SPRAYING APPLE ORCHARDS IN 1913 AND 1914 439 codling moth rapidly increased. Practically all dropped apples which were picked up under check trees during August and September, showed codling-moth injury. In some of them as many as eight worm- holes appeared in a single apple. FIG. 2. — 2,325 DROPPED APPLES FROM AN UNSPRAYED TREE, NEOGA, 1913 FIG. 3. — 203 DROPPED APPLES FROM A PROPERLY SPRAYED TREE, NEOGA, 1913 About September 1, a very heavy drop of apples occurred from the unsprayed trees. This continued for ten days, when it suddenly stopped ; very few apples fell from then until picking time. In Fig. 2 are shown 2,325 apples picked up under one unsprayed tree, while in Fig. 3 are shown 203 apples from an adjoining, properly sprayed tree. An examination of these apples revealed the presence of much codling-moth injury. SUMMARY OF RESULTS AT NEOGA, 19 j 3 1. Differences in the control of codling moth shown in these ex- periments by the various brands of arsenates of lead are attributed not so much to differences in the chemicals themselves as to unequal conditions of infection, arising chiefly from wide variations in the quantity of fruit borne by the different plats. 440 BULLETIN No. 206 [April, 2. The powdered arsenates of lead proved very convenient to handle. The Vreeland brand caused a slight injury to the foliage which was not noticed in the plats sprayed with Corona dry. 3. A fourth application of arsenate of lead applied to Jonathan trees to check the ravages of second-brood codling moth was very effective, reducing the injury from this insect several percent wherever used. 4. A fourth application of arsenate of lead applied early in July failed to control third-brood codling moth, which appeared early in October, infesting unpicked apples. 5. The infestation of codling moth was the most serious in the history of the experimental work at Neoga. 6. Arsenate of lead applied at 125 pounds pressure controlled codling moth almost as well as that applied at 225 pounds pressure. 7. Bordeaux applied at 125 pounds pressure caused no injury, while pressures of 160 pounds and higher appeared to cause consid- erable russetihg of the fruit and some foliage injury. 8. A heavy drop of Jonathan apples early in September appeared to have been caused by attacks of codling-moth. 1918] SPRAYING APPLE ORCHARDS IN 1913 AND 1914 441 SPRAYING EXPERIMENTS IN 1914 AT NEOGA, CUMBERLAND COUNTY BY O. S. WATKINS OBJECTS The investigations at Neoga in 1914 were made to determine (1) the insecticidal efficiency of certain brands of arsenate of lead, alone and in combination with lime sulfur; (2) the fungicidal efficiency of soluble sulfur, atomic sulfur, calcium hyposulfite, copper ferro- cyanide, and tuber tonic; (3) the effect of varying the pressure in applying Bordeaux; and (4) the effectiveness of certain standard nozzles. Conditions arising during the season made it possible to obtain information also on the effects of ( 1 ) special sprays applied to control delayed broods of codling moth; and (2) banding the trees as a supplementary means of controlling codling moth. LOCATION AND DESCRIPTION OF ORCHARDS Two apple orchards were used in carrying on these experiments. The neglected Storer orchard, located one and one-half miles ngrth- west of Neoga, was selected for testing the fungicidal value of certain sprays applied during the dormant season. This orchard, consisting of eleven acres, was about eighteen years old, and was planted to sev- eral varieties, including Ben Davis, Winesap, and Willow. For the customary detailed experimental work, fourteen acres of trees were selected from the 120-acre orchard owned by H. A. Aldrich and Com- pany. The experimental blocks consisted of five acres of Black Ben Davis, two acres of Grimes, and five acres of Jonathan trees. These blocks of trees were separated by rows of other varieties which were cared for by H. A. Aldrich and Company. Each block was divided into plats of from five to fourteen trees each. At regular intervals, unsprayed trees were reserved for comparison with the sprayed trees. APPARATUS AND MATERIALS The sprays were applied with a Friend power sprayer equipped with a New Western motor pump and 100-gallon tank. The power- ful engine and large-capacity pump insured a sufficient range of pressure for all experiments, while the small tank proved convenient and efficient for applying the comparatively small amounts of spray required for each plat. 442 BULLETIN No. 206 [April, In the test of the effectiveness of various types of nozzles Bordeaux, Morrel and Morley Eclipse, Friend, and Gould Mistry nozzles were compared. In all other tests a single Friend angle nozzle was used on the tower, pole and a double Gould Mistry nozzle on the ground pole. The standard spraying materials were prepared according to the directions given on pages 430 and 431, with the exceptions noted in connection with the individual experiments. A constant pressure of 135 pounds was used in all experiments except those on comparisons of pressures. WEATHER CONDITIONS The weather conditions of 1914 were hardly normal. There were several rains during the summer, but other conditions were such as to counteract much of the good they might have done. In May, three rains gave a precipitation of seven-eighths inch; in June, six rains gave three inches ; in July, six rains gave one and one-fourth inches ;. in August, eight rains gave five inches; and in September, four rains gave three inches. During June there were six days when the ther- mometer passed 100° F., and during July there were eleven such days. The general character of the season was hot and dry, in spite of the fact that there was a reasonable total precipitation. Full bloom was recorded from April 28 to May 1. There was very heavy bloom on the Ben Davis and the Black Ben Davis trees, a fair bloom on the Grimes, and a scattering bloom on the Jonathan trees. Excellent weather for pollination prevailed, and the blooms set well. SPRAY DATES All plats in the Aldrich orchard were given an application of winter-strength lime sulfur early in April. Four to six later appli- cations were made upon or near the following dates : April 25, May 5, May 18, June 14, July 8, and September 1. The applications on June 14 and September 1, made especially to combat the ravages of codling moth, were in addition to the usual schedule. INSECTICIDAL EFFICIENCY OF CERTAIN BRANDS OF ARSENATE OF LEAD USED ALONE AND IN COMBINATION WITH LIME SULFUR Each plat in this group consisted of five trees of the Black Ben Davis variety. All plats were sprayed under conditions as nearly alike as possible. The brands of arscnate of lead tested and the treat- ments given are presented in Tables 6 and 7. Owing to the late ar- rival of the material, Plat 13, sprayed with Grasselli powdered arse- mite of lead, and Plat 19, sprayed with the same material and lime sulfur, did not receive the first, or cluster-bud application. 1918] SPRAYING APPLE ORCHARDS IN 1913 AND 1914 443 EFFECT ON FOLIAGE Careful observations disclosed no spray injury on any of the plats. Of the arsenates of lead used alone, Corona dry and Sherwin-Williams dry appeared to be the most adhesive. EFFECT ON FRUIT The fruit from the plats sprayed with arsenate of lead alone was picked and examined October 16 and 17, with the results presented in Table 6. The character of the codling-moth infestation was so severe as to give an excellent opportunity for testing the effectiveness of poison sprays in its control. The infestation of the two check plats was 84 and 97.3 percent, respectively. Many of the unsprayed apples were entered by several larvae; had the individual larvse entrances TABLE 6. — EFFECTS OF VARIOUS BRANDS OF ARSENATE OF LEAD USED ALONE IN CONTROLLING CODLING MOTH ON BLACK BEN DAVIS APPLES, IN THE EXPERIMENTS AT NEOGA, 1914 Plat Treatment Applica- tions Picked apples Total No. Per- cent- age No. 1 Percentage affected by codling moth Calyx Side Total 7 Check 8 9 10 11 12 Check 13 14 15 2-100 Corona dry arsenate of lead 1, 2, 3, 4, 5, 6 None 1, 2, 3, 4, 5, 6 1,2,3,4,5,6 1, 2, 3, 4, 5, 6 1, 2, 3, 4, 5, 6 1,2,3,4,5,6 None 2, 3, 4, 5, 6 1, 2, 3, 4, 5, 6 1,2,3,4,5,6 710 332 2072 1916 2641 2387 1162 231 2688 1704 1707 80 0 76 89 80 84 73 0 46 81 83 0.4 12.3 0.1 0.5 0.3 0.2 4.0 17.0 4,7 0.5 .0 4.3 85.0 2.0 5.9 5.2 4.4 12.0 67.0 27.0 6.3 3.6 4,7 97.3 2.1 6.4 5.5 4.6 16.0 84.0 31.7 6.8 3.6 No treatment 4-100 Corona dry arsenate of lead 2-100 Sherwin-Williams dry arsenate of lead . . . 4-100 Sherwin-Williams dry arsenate of lead . . . 4-100 Sherwin-Williams paste arsenate of lead. . 4-100 Grasselli paste arse- nate of lead No treatment 2-100 Grasselli powdered arsenate of lead ....... 4-100 Thomsen triplumbic paste arsenate of lead. . 4-100 Dow paste arsenate of lead been counted instead of the number of apples attacked, the infesta- tion would have been represented by several hundred percent. Tn view of the severe infestation, all the treatments, except those of Plats 12 and 13, gave a satisfactory control of codling moth, the in- festation ranging from 2.1 to 6.8 percent. On Plats 12 and 13, sprayed with Grasselli paste and poAvdcred arsenates of lead, respectively, the codling-moth infestation amounted to 16 and 31.7 percent. Grasselli 444 BULLETIN No. 206 [April, powdered arsenate of lead proved difficult to keep in suspension. Corona and Sherwin-Williams dry arsenates of lead were of practi- cally the same efficiency as the pastes. The use of 2 pounds of dry arsenate of lead in each 100 gallons of spray was almost as efficient as 4 pounds, indicating that, for practical purposes, the smaller amount is sufficiently effective. The fruit from the plats sprayed with arsenate of lead and lime sulfur was picked and examined October 23 ; the results are presented in Table 7. As will be seen, there were no wide differences in the effectiveness of the different arsenates of lead in controlling codling moth. Altho not shown in the table, it should be stated that none of the sprays caused injuries of any kind to the fruit. TABLE 7. — EFFECTS OF VARIOUS BRANDS OF ARSENATE OF LEAD USED IN COMBINA- TION WITH LIME SULFUR IN CONTROLLING CODLING MOTH ON BLACK BEN DAVIS APPLES, IN THE EXPERIMENTS AT NEOGA, 1914 Plat Treatment Appli- ca- tions Picked apples Total No. Percentage affected by codling moth Calyx Side Total 16 17 Check 18 19 20 21 4-100 Dow paste arsenate of lead with lime sulfur 1,2,3,5 4,6 1,2,3,5 4,6 None 1,2,3,5 4,6 2,3,5 4,6 1,2,3,5 4,6 1,2,3,5 4,6 1292 1841 456 1412 1440 876 902 2.5 2.4 6.0 2.5 2.0 1.0 1.2 8.6 9.2 51.0 5.0 7.0 7.0 8.0 11.1 11.6 57.0 7.5 9.0 8.0 9.2 2-100 Corona dry arsenate of lead with lime 4-100 Sherwin-Williams paste arsenate of lead with lime sulfur 2-100 Corona dry arsenate of lead with lime No treatment 2-100 Sherwin-Williams dry arsenate of lead with lime sulfur 2-100 Corona dry arsenate of lead with lime 2-100 Grasselli powdered arsenate of lead with lime sulfur 2-100 Corona dry arsenate of lead with lime 4-100 Thomsen triplumbic paste arse- nate of lead with lime sulfur 2-100 Corona dry arsenate of lead with lime . . . 2-100 Corona dry arsenate of lead with lime sulfur 2-100 Corona dry arsenate of lead with lime A comparison of Table 6 with Table 7 shows that a better control of codling moth was exercised by arsenate of lead alone than by arse- 1018] SPRAYING APPLE ORCHARDS IN 1913 AND 1914 445 nate of lead with lime sulfur. The difference, tho small, was con- sistent enough to indicate that the lime sulfur lessened the poisoning efficiency of the arsenate of lead or else proved attractive in some way to codling moth. The latter possibility would confirm observations recorded in Bulletin 185 (page 203). FUNGICIDAL EFFICIENCY OF SOLUBLE SULFUR, ATOMIC SULFUR, CAL- CIUM HYPOSULFITE, COPPER FERROCYANIDE, AND TUBER TONIC Niagara and Grasselli soluble sulfur, Thomsen atomic sulfur, cal- cium hyposulfite, copper ferrocyanide, and Sherwin-Williams tuber tonic were compared on plats consisting of ten Jonathan and four Grimes trees each. Lack of fungous infection, however, prevented obtaining information relating to the fungicidal value of these sprays. Copper ferrocyanide appeared to be the most adhesive; the other sprays were about equal in this respect. The fruit sprayed with 'cal- cium hyposulfite was more highly colored than that in any of the other plats. Tuber tonic seriously burned every leaf and injured every blossom to which it was applied, entirely destroying the crop from that plat, showing conclusively that it is a worthless and dan- gerous spray for apples. Soluble sulfur, used alone, caused slight foliage injury. Atomic sulfur injured about 10 percent of the fruit, causing a burn similar to lime-sulfur injury. < EFFECT OF PRESSURE ON BORDEAUX EUSSET The effects of applications of different pressures on Bordeaux rus- set were compared on plats each consisting of ten Jonathan and four Grimes trees. The results are not tabulated, but may be stated as follows: Bordeaux applied at pressures above 150 pounds did not cause very much russet. Apples sprayed at higher pressures, how- ever, were not so well colored as those sprayed at 135 pounds. Grimes apples sprayed at pressures of 175 pounds and higher were covered with minute russeted specks, hardly noticeable enou'gh, however, to lessen their selling value. EFFECTIVENESS OF CERTAIN STANDARD NOZZLES Each plat in this group consisted of five Black Ben Davis trees. The sprays were applied with the nozzles named in Table 8. EFFECT ON FOLIAGE No differences in the appearance of the foliage in the various plats could be detected. More material was required when spraying with Bordeaux nozzles than with other nozzles, as much of it was lost on the ground. 446 BULLETIN No. 206 [April, EFFECT ON FRUIT The fruit was picked and examined October 26, giving the results presented in Table 8. There were no appreciable differences in the effectiveness of the different nozzles in their degree of control of cod- ling moth. The drenching spray of the Bordeaux nozzle saved no more fruit from second-brood codling moth than the misty, fog-like sprays from the other nozzles. In controlling the first brood, however, this nozzle was the most efficient. Owing to the absence of fungous diseases, there was no opportunity to compare the efficiency of the different nozzles in controlling them. TABLE 8. — EFFECTS OF USING DIFFERENT KINDS OF NOZZLES IN APPLYING STANDARD SPRAY MIXTURES TO BLACK BEN DAVIS APPLES, IN THE EXPERIMENTS AT NEOGA, 1914 Plat Nozzle used Picked apples Total No. Percentage affected by codling moth Calyx Side Total 28 29 30 Check Bordeaux 2100 732 1335 282 .2 3.2 5.0 14.7 16.2 12.6 13.8 76.0 16.4 15.8 18.8 90.7 Merrill and Morley Eclipse One Friend and one Gould Mistry No treatment EFFECTS OF SPECIAL SPRAYS APPLIED TO CONTROL DELAYED BROODS OF CODLING MOTH In 1914 most of the first-brood codling moth appeared about the middle of June, a month later than usual. Late in August and on into September an apparently delayed second brood, the offspring of the delayed first brood, appeared. As no provision had been made in the regular spray schedule for applications to control codling moth ap- pearing at these times, it was necessary to resort to extra sprays ap- plied as soon as a diagnosis of this unusual condition could be made. These extra sprays were applied June 14 and September 1. To learn their effectiveness, the first one was omitted from one plat, the last one from another, and both from a third. Each plat consisted of five Black Ben Davis trees. The effects of the extra sprays are shown in Table 9. These results show that the two extra sprays saved slightly more than half the total crop, reducing the injury from 56 percent in Plat J, which received only the regular applications, to 4.7 percent in Plat G, which received both extra applications in addition to the regular sprays. One extra application was helpful, but insufficient to give a satisfactory control of codling moth. The excellent results obtained in this experiment, carried on in a season when codling moth was at its worst, show conclusively that it 1918} SPRAYING APPLK ORCHARDS IN 1913 AND 1914 447 is possible to keep such close track of the development of the insect as to spray at such times as to hold it effectively in check. TABLE 9. — EFFECTS OF SPECIAL APPLICATIONS OF ARSENATE OF LEAD APPLIED TO CONTROL DELAYED BROODS OF CODLING MOTH, IN THE EXPERIMENTS AT NEOGA, 1914 Plat Treatment Appli- ca- tions Picked apples Total No. Per- cent- age No. 1 Percentage affected by codling moth Calyx Side Total G H 1 J Check FoTir regular sprays 1,2,3,5 4,6 1,2,3,5 6 1,2,3,5 4 1,2,3,5 None 710 496 1360 366 456 80 51 48 22 0 0.4 8.3 11.0 4.9 6.0 4.3 29.0 23.0 51.1 51.0 4.7 37.3 34.0 56.0 57.0 Extra applications in June and September Four regular sprays Extra application in Septem- ber only Four regular sprays Extra application in June only Four regular sprays No extra applications No treatment NOTE. — For all applications 2-100 Corona dry arsenate of lead with lime was used. t EFFECTS OF BANDING THE TREES AS A SUPPLEMENTARY MEANS OF CONTROLLING CODLING MOTH When it became evident in June that a strenuous fight would have to be made to control codling moth, it was decided to place trap bands of paper or burlap on the trees in order to catch as many larvae and pupae as possible. The rough bark was first scraped from the tree trunks, when it is estimated that more than 6,000 larvae were killed. Two bands were then placed on each tree, one six inches above the ground and the other just below the crotch. These were examined every seven days thruout the summer. The banding resulted in the trapping and subsequent destruction of more than 14,000 larvae. In the bands on one of the unsp rayed trees, 154 larvae were found at one examination. It is believed, therefore, that banding is a useful sup- plement to spraying in controlling codling moth. SUMMARY OF RESULTS AT NEOGA, 1914 1. Arsenate of lead, properly applied, controlled codling moth in spite of the severe 1914 infestation. 2. Arsenate of lead received from the Grasselli Chemical Com- pany was less efficient in the control of codling moth than Corona dry, 448 BULLETIN No. 206 [April, Sherwin-Williams paste and dry, Thomsen triplumbic paste, and Dow paste arsenates of lead. 3. Corona dry and Sherwin-Williams dry arsenates of lead were equivalent in efficiency to the pastes. 4. Two pounds of Corona dry and two pounds of Sherwin-Wil- liams dry arsenate of lead were practically as efficient as four pounds of the same material, as well as four pounds of any of the standard paste arsenates of lead. 5. All the arsenates of lead were less effective when used with lime sulfur than when used alone. • 6. Copper ferrocyanide proved to be very adhesive. 7. Fruit sprayed with calcium hyposulfite was very highly col- ored. 8. Sherwin-Williams tuber tonic caused severe injury to the foli- age and fruit. 9. Niagara soluble sulfur and Grasselli soluble sulfur caused a small amount of foliage injury. 10. Thomsen atomic sulfur burned about 10 percent of the fruit. 11. Drenching trees by the use of the Bordeaux nozzle did not prove any more efficient than spraying thru nozzles producing a mist in controlling second-brood codling moth, but was more efficient in controlling the first brood. 12. Owing to the irregularity with which codling moth appeared, over half the fruit from trees which were not given special applications for the delayed broods was infested. 13. Thirty-seven percent of the fruit from trees given one special application in September was injured by codling moth; 34-percent infestation resulted when one special application was given in June; while in properly sprayed fruit, receiving four regular applications and two special applications, the injury amounted to only 5 percent. 14. Banding trees with paper or burlap bands was found a satis- factory means of trapping the larvae of the codling moth, thus afford- ing an opportunity to kill them before they had transformed into moths. 1918] SPRAYING APPLE ORCHARDS IN 1913 AND 1914 449 SPRAYING EXPERIMENTS IN 1913 AT FLORA, CLAY COUNTY BY W. A. RUTH, ASSOCIATE IN HORTICULTURAL CHEMISTRY OBJECTS The principal object of this experiment was to determine the ef- fect of varying the amount of Bordeaux applied, the pressure at which the spray was applied, and the size of the nozzle openings, on the production of Bordeaux russet. A secondary object was to determine the effect of varying these factors on the control of insects and fungi. BORDEAUX RUSSET : DESCRIPTION AND CAUSE Aside from producing foliage injury, Bordeaux will bring about severe russeting of the fruit if applied to certain varieties of apples under certain conditions. Some varieties are more subject to russeting than others ; the varieties Ben Davis and Jonathan, upon which this experiment was carried out, may be classed among the more suscepti- ble. The russeting is due to the production of corky material which replaces the surface injured by the spray. This corky surface is usu- ally light brown, but may be dark brown or black if the russeted areas are very small. The injury may be confined to scattered dots'; if more severe, there may be irregular russeted streaks as well as dots ; and if very severe, all or a large part of the surface of the fruit may be russeted. The injury, according to Hedrick,1 follows applications of Bor- deaux made early in the season ; later in the season, according to this investigator, after the hairs have been shed and the stomata changed into lenticels, immunity is probably acquired. At Flora, in experi- ments conducted by the writer in 1912 with Ben Davis and Jonathan trees, the application of Bordeaux made in April, just before the bloom, and the two following the bloom, made in May, all caused serious damage.2 The application of this material made about July 1, how- ever, when the apples were acquiring a waxy surface, caused no severe russet; a slight dotting was produced at this time, but it be- came inconspicuous by the time the fruit was ready to be picked.- Ex- periments conducted with Ben Davis trees by Mr. A. J. Gunderson2 at Griggsville showed that any one of the early applications of Bor- deaux may result in the culling of a large part of the crop. When Bordeaux was first used there was little complaint of injury. The apparatus with which the material was applied at that time was JU. P. Hedrick, New York (Geneva) Agr. Exp. Sta. Bui. 287, p. 163. 2J. C. Blair et al., 111. Agr. Exp. Sta. Bui. 185. 450 BULLETIN No. 206 [April, very crude compared with the machinery now employed. On account of the much greater pressures used since power sprayers have reached their present state of perfection, the increase in russeting has often been attributed to these greater pressures. A further basis for the assumption that pressure is a most important factor in the formation of russet is the difference in the severity of the russeting often to be observed in commercial orchards sprayed at high and at low pressures. In support of this idea a mechanical explanation was apparently at hand. According to this explanation the damage follows punctures made by gritty particles in the Bordeaux, and the number of the punctures and the severity of the resultant injury increase with the pressure. 1 ooooooo ooooo ooooo Davis Ben Povis ChecK than FIG. 4. — PLAN OF PLATS IN ORCHARD OF MRS. JOHN EGGINTON, FLORA, 191J1 NOTE. — The neglected orchard was located immediately to the right. .1918] SPRAYING APPLE ORCHARDS IN 1913 AND 1914 451 It can hardly be assumed that a difference in the pressure is the only difference between the methods now used for applying the spray and those used formerly, or between high and low pressure spraying. More thoro spraying is probably done with power sprayers than was done before they came into use, and larger amounts of spray material per tree are no doubt being applied. Moreover, larger amounts are usually applied at high pressures than at low pressures. The pressure indicated at the pump cannot be assumed to be an accurate indicator of the striking force of the particles ; the type of nozzle and the size of the nozzle openings affect the size of the drops of spray, and, in all probability, their striking force to at least as great an extent as their size. Even with nozzle openings of a uniform size, a high pressure breaks the spray into finer particles than does a low pressure.1 It may therefore be imagined that the possible striking and injuring force may be actually greater if low pressures are used than would result from the use of high pressures, especially if large nozzle openings are used with the low pressures, and small nozzle openings with the high. LOCATION AND DESCRIPTION OF ORCHARD The orchard used in this experiment was the property of Mrs. John Egginton, and was located four and one-half miles west of Flora. The trees, which were well cared for, were seventeen years old the season of the experiment. A gradual, even slope, and a draw adjoining the lower end, provided good air drainage, especially for the upper third of the orchard, across which the plats were run. A neglected orchard immediately adjoined this part of the orchard. The arrangement of the plats is shown in Fig. 4. TREATMENT In order to restrict the number of plats, but one high and one low pressure were tested, one size of large nozzle opening and one size of small, and, as far as possible, a uniform large and a 'uniform small amount of spray. To obtain all the possible combinations of the three factors the experiment would have included eight treatments. The possible combinations and the methods used are shown in Table 10. Bordeaux arsenate of lead was used for the first and fourth applica- tions, and lime sulfur arsenate of lead for the two intermediate ap- plications. When small amounts of spray were applied, the foliage was covered lightly but thoroly. With large amounts, the foliage was drenched. There was more or less unavoidable variation in the amounts applied to the plats in each class. The spray was applied from the upper side, most of the spray which reached the under sides of the leaves being that carried thru the tree at the high pressure. The high pressure ST. W, Lloyd, HI. Agr. Exp. Sta. Bui. 114, p. 385. 452 BULLETIN No. 206 [April, was between 225 and 250 pounds, the low pressure, between 125 and 150 pounds. The large nozzle openings had twice the area of the small nozzle openings. TABLE 10. — TREATMENTS IN THE EXPERIMENTS AT FLORA, 1913 Plat Pressure Amount of spray Size of nozzle openings 1 2 3 _i 4 5 6 7 High Low Low High High Low High Low Large Large Small Small Small Small Large Large Large Large Large Large Small Small Small Small because of the difficulty involved in distributing a small amount of spray evenly at a high pressure with large nozzle openings, this combination of factors was not tested. The material was applied in the following manner : Each plat was completely sprayed at one time, with material made up and carried in one load. Each plat was sprayed from one side, thru the middle, and then from the other side, so that the trees of both varieties were finished practically at the same time, and that any possible differences in the method of spraying, which in any case would be slight, would be equalized as far as possible between the varieties. The first, second, and third applications, which are, taken together, responsible for the control of scab, leaf spot (Spliceropsis malorum Pk.), first-brood codling moth, and the apple-leaf roller (Ar chips rosa- ceana Harris), were applied at favorable times. The third application is also partly responsible for the control of blotch. The apple flea- weevil (Orchestes canus Horn) confines its feeding to the earlier part of the season, and would be controlled by the early sprays if it is to be controlled according to the present schedule. The fourth applica- tion, which is designed to' be partly responsible for the control of blotch (PTiyllosticta solitaria E. & E.), directly responsible for the control of second-brood codling moth, and indirectly responsible for the control of the third brood, wras applied too late to be of any great benefit. APPARATUS AND MATERIALS The sprays were prepared according to the methods described on pages 430 and 431. The Illinois formula was used in making the lime sulfur. Grassclli paste arsenatc of lead, at the rate of 4 pounds to 100 gallons of spray, was always added to the fungicide. In applying the sprays, Bean whirlpool nozzles were used. The discs of these nozzles, which are interchangeable, are regularly fur- 1918} SPRAYING APPLE ORCHARDS IN 1913 AND 1914 453 nished with holes approximately .07 or .05 inch in diameter, and these sizes were used as the ' ' large ' ' and the ' ' small ' ' nozzle openings. The whirlpool type of nozzle is made by several firms, and is in common use in commercial orchards. Two power sprayers were used, one for the high-pressure sprays, the other for those applied at the low pres- sure. Both outfits were equipped with good propeller agitators. WEATHER CONDITIONS The weather during April, May, and the first part of June was very cool, and there was enough moisture to allow an attack of scab and blotch. The remainder of the season was unusually hot and dry. Conditions were favorable for the multiplication of codling moth. SPRAY DATES Four summer applications were made upon the following dates: April 17 to 19, May 7 to 8, May 28 to 31, and August 8 to 10. The fourth application was made after the danger of Bordeaux russeting was past. EFFECT OF THE SPRAYS ON FOLIAGE Leaf spot was thoroly controlled on all the sprayed trees, but caused a heavy loss of foliage on the unsprayed Ben Davis trees. «A severe scab infection was present on the Ben Davis fruit, altho the foliage of the check trees of both varieties was almost free from this injury. By the middle of June the foliage of both the sprayed and the un- sprayed trees was thoroly riddled by apple flea-weevil. The first over- wintering adults were observed April 3 ; the adults of the new gen- eration were present on the foliage in the greatest numbers during the latter part of May and the first two weeks in June. At the ends of the plats immediately adjoining the neglected or- chard, apple-leaf rollers severely damaged the foliage of two or three rows of trees. On the trees farther away, the sprays controlled these insects to a large extent. EFFECT OF THE SPRAYS ON FRUIT The effects of varying each one of the three factors, pressure, amount, and size of nozzle opening, as tested on each of the two varie- ties, are presented in Tables 11 to 16. In each table three plats are compared with three other plats; each of the three plats shown on one side of the table was treated similarly to the opposite one of the other three, except for one varying factor common to the entire group of six. In the first two tables the pressure at which the spray was 454 BULLETIN No. 206 [April, applied is the common varying factor ; in the next two it is the amount of spray; and in the last two it is the size of the nozzle openings. On account of the large number of codling moths and the small and scattered crop of fruit, the degree of control of these insects can- not be attributed entirely to the relative efficiency of the various treatments. It is well known that, with a small crop and an abun- dance of moths, control is especially difficult. When the set of fruit varies among various plats, following a scattered bloom, as it did in this experiment, especially on the Ben Davis trees, differences in con- trol must be due to some extent to differences in the set. For this rea- son, codling-moth data of Ben Davis fruit are omitted in the following tables. The data for the control of these insects entering the calyxes of the Jonathans, however, seem to be fairly consistent, and are there- fore presented. All the picked Jonathans were examined for the vari- ous injuries recorded, but only the Ben Davis apples from the end of the plats farthest from the neglected orchard. TABLE 11. — EFFECT OF SPRAYING BEN DAVIS APPLES WITH DIFFERENT PRESSURES, IN THE EXPERIMENTS AT FLORA, 1913 l Amount of spray Size of nozzle openings High pressure Low pressure Plat Percentage of picked apples affected by— Plat Percentage of picked apples affected by — Scab Blotch Severe russet Scab Blotch Severe russet Large Small Large Large Small Small 1 4 6 .0 5.5 .5 6.2 29.4 13.3 30.6 13.9 23.8 2 5 7 .0 8.8 4.6 3.7 32.3 13.6 33.4 8.3 25.3 No treatment Average Check 2.0 62.2 16.3 56.6 22.8 2.1 Average Check 4.5 62.2 16.5 56.6 22.3 2.1 TABLE 12. — EFFECT OF SPRAYING JONATHAN APPLES WITH DIFFERENT PRESSURES, IN THE EXPERIMENTS AT FLORA, 19131 Amt. of spray Size of nozzle open- ings High pressure Low pressure Plat Percentage of picked apples affected by — Plat Percentage of picked apples affected by — Scab Blotch Codling moth (calyx) Severe russet Scab Blotch Codling moth (calyx) Severe russet Large Small Large Large Small Small 1 4 6 .9 2.0 .6 6.1 19.5 5.5 6.3 13.8 4.0 5.7 7.7 36.9 2 5 7 .2 2.5 1.0 5.4 18.9 11.2 4.8 23.2 11.4 17.9 18.4 37.5 No treatment Aver- age Check 1.2 34.9 10.4 52.6 8.0 50.1 16.8 2.9 Aver- age Check 1.2 34.9 11.8 52.6 13.1 50.1 24.6 2.9 'Each plat was sprayed four times; Bordeaux arsenate of lead was used for the first and fourth applications, and lime sulfur arsenate of lead for the two intermediate applications. 1918] SPRAYING APPLE ORCHARDS IN 1913 AND 1914 455 EFFECT OF VARYING THE PRESSURE On the Ben Davis apples, the amount of russet produced by the spray was practically equal at both pressures. On the Jonathan apples, more russet was produced, in every case, at low than at high pressure. On both varieties, blotch and scab were controlled, on the average, with almost equal thoroness at both pressures. The control of codling moths entering the calyxes of the Jonathans was better, on the average, where the spray was applied at high pressure. EFFECT OF VARYING THE AMOUNT OF SPRAY In every case where comparisons could be made, the use of a large amount of spray resulted in decidedly more russet than the use of a small amount. The control of scab and blotch on both varieties, and of codling moths entering the calyxes of the Jonathans, was better, and with one exception much better, where large amounts of spray were used. TABLE 13. — EFFECT OF SPRAYING BEN DAVIS APPLES WITH DIFFERENT AMOUNTS, IN THE EXPERIMENTS AT FLORA, 1913 l Pres- sure Size of nozzle openings Large amount Small amount Plat Percentage of picked apples affected by — Plat Percentage of picked apples affected by-j- Scab Blotch Severe russet Scab Blotch Severe russet Low High Low Large Small Small 2 6 7 .0 .5 4.6 3.7 13.3 13.6 33.4 23.8 25.3 3 4 5 4.4 5.5 8.8 32.8 29.4 32.3 15.8 13.9 8.3 No treatment Average Check 1.7 62.2 10.2 56.6 27.5 2.1 Average Check 6.2 62.2 31.5 56.6 12.7 2.1 TABLE 14. — EFFECT OF SPRAYING JONATHAN APPLES WITH DIFFERENT AMOUNTS, IN THE EXPERIMENTS AT FLORA, 1913 l Pres- sure Size of nozzle open- ings Large amount Small amount Plat Percentage of picked apples affected by — Plat Percentage of picked apples affected by — Scab Blotch Codling moth (calyx) Severe russet Scab Blotch Codling moth (calyx) Severe russet Low High Low Large Small Small 2 6 7 .2 .6 1.0 5.4 5.5 11.2 4.8 4.0 11.4 17.9 36.9 37.5 3 4 5 1.5 2.0 2.5 14.4 19.5 18.9 7.9 13.8 23.2 9.0 7.7 18.4 No treatment Aver- age Check .6 34.9 7.4 52.6 6.7 50.1 30.8 2.9 Aver- age Check 2.0 34.9 17.6 52.6 15.0 50.1 11.7 2.9 1 Each plat was sprayed four times; Bordeaux arsenate of lead was used for the first and fourth applications, and lime sulfur arsenate of lead for the two intermediate applications. 456 BULLETIN No. 206 [April, EFFECT OF VARYING THE SIZE OF THE NOZZLE OPENINGS In every case more russet was produced on the Ben Davis apples sprayed with large nozzle openings than on those sprayed with small nozzle openings, while the opposite result was produced in every case on the Jonathans. On the average, three times as much russet ap- peared on Jonathan apples sprayed with large nozzle openings as on those sprayed with small nozzle openings. The difference may be due to a greater susceptibility of the Jonathan tissue to a small amount of Bordeaux, in comparison to its susceptibility to a large amount, and to a better distribution of the spray. The better distribution, which would follow the use of small nozzle openings and the production of a finer mist, might result in the production of a greater number of smaller covered areas. The use of low pressures, in comparison with high pressures, modifies the distribution in the same way, and, as has been stated in the discussion of the effect of varying the pressure, produces the same result. TABLE 15. — EFFECT OF SPRAYING BEN DAVIS APPLES WITH DIFFERENT-SIZED NOZZLE OPENINGS, IN THE EXPERIMENTS AT FLORA, 1913 l Pres.- sure Amount of spray Large nozzle openings Small nozzle openings Plat Percentage of picked apples affected by — Plat Percentage of picked apples affected by — Scab Blotch Severe russet Scab Blotch Severe russet High Low Low Large Large Small 1 2 3 .0 .0 4.4 6.2 3.7 32.8 30.6 33.4 15.8 6 7 5 .5 4.6 8.8 13.3 13.6 32.3 23.8 25.3 8.3 No treatment Average Check 1.5 62.2 14.2 56.6 26.6 2.1 Average Check 4.6 62.2 19.7 56.6 19.1 2.1 TABLE 16. — EFFECT OF SPRAYING JONATHAN APPLES WITH DIFFERENT-SIZED NOZZLE OPENINGS, IN THE EXPERIMENTS AT FLORA, 1913 l Pres- sure Amt. of spray Large nozzle openings Small nozzle openings Plat Percentage of picked apples affected by — Plat Percentage of picked apples affected by — Scab Blotch Codling moth (calyx) Severe russet Scab Blotch Codling moth (calyx) Severe russet High Low Low Large Large Small 1 2 3 .9 .2 1.5 6.1 5.4 14.4 6.3 4.8 7.9 5.7 17.9 9.0 6 7 5 .6 1.0 2.5 5.5 11.2 18.9 4.0 11.4 23.2 36.9 37.5 18.4 No treatment . Aver- age Check .9 34.9 8.6 52.6 6.3 50.1 10.9 2.9 Aver- age Check 1.4 34.9 11.9 52.6 12.9 50.1 30.9 2.9 *Each plat was sprayed four times; Bordeaux arsenate of lead was used for the first and fourth applications, and lime sulfur arsenate of lead for the two intermediate applications. 1918] SPRAYING APPLE ORCHARDS IN 1913 AND 1914 457 The control of scab and blotch was better on Ben Davis apples when large nozzle openings were used. The same was true for blotch and codling-moth calyx injury on the Jonathans. Scab on the Jon- athans was controlled almost equally well when large and small nozzle openings were used. SUMMARY OF RESULTS AT FLORA, 1913 1. The amount of spray applied was the most important factor in the production of russet ; large amounts increased this injury, but were more effective in protecting the fruit from scab, blotch, and codling moth entering the calyxes, than were small amounts. 2. It was conclusively shown that applying the spray at high pressure did not increase the amount of Bordeaux russet. The pres- sure employed had no effect on the control of scab or blotch, but the value of high pressures in the control of codling-moth calyx injury was indicated. 3. On the Ben Davis apples, a greater amount of russet was pro- duced where large nozzle openings were used than where small nozzle openings were used ; on the Jonathan apples, the use of small nozzle openings gave the greater amount of russet. Large nozzle openings gave a better control, in general, of scab, blotch, and codling-moth calyx injury. , 4. Spraying was of no value in controlling the apple flea-weevil. 5. The foliage of all the sprayed plats was well protected from leaf spot. 6. The foliage of all the sprayed plats was well protected from the apple-leaf roller except on the trees adjoining the neglected or- chard. 458 BULLETIN No. 206 [April, SPRAYING EXPERIMENTS IN 1913 AT GRIGGSVILLE, PIKE COUNTY BY ALFRED J. GUNDERSON, FIRST ASSISTANT IN POMOLOGY OBJECTS In the spraying work at Griggsville during 1913, experiments were conducted with a view to studying the following points in summer spraying: (1) the relative values of lime sulfur and Bordeaux ; (2) the effects of using Bordeaux for some applications and lime sulfur for other applications in the same season's operations; (3) the rela- tive values of paste and powdered arsenates of lead ; (4) the relative values of various strengths of lime sulfur; (5) the fungicidal and insecticidal values of copper ferrocyanide made in different ways; (6) the relative values of proprietary lime-sulfur compounds; (7) the relative values of light and heavy applications of lime sulfur arse- nate of lead and Bordeaux arsenate of lead. LOCATION AND DESCRIPTION OF ORCHARD The orchard used for these experiments belonged to Mr. C. G. Winn, and was located one and one-half miles south of Griggsville. A block of 179 fifteen-year-old Ben Davis trees, planted thirty-two feet apart each way, was chosen for the work. In laying out the experiments, the trees were divided into twenty- eight plats of four to six trees each, and two unsprayed or check rows were left thru the entire length of the orchard. The plats which were to be compared were grouped, and those of each group were sprayed as nearly as possible under the same conditions. The arrangement of the plats is shown in Fig. 5. APPARATUS AND MATERIALS The standard sprays were prepared as described on pages 430 and 431. Applications were made with a Gould hand spray outfit at 115 to 125 pounds pressure. Friend disc nozzles were used. WEATHER CONDITIONS The weather during April, May, and the first part of June was cool, with very little rain. The remainder of the season was unusually ftot and dry. 1918] SPRAYING APPLE ORCHARDS IN 1913 AND 1914 459 n D 'avis ^) Den Davis ^J Other Varieties CfiecK FIG. 5. — PLAN OF PLATS IN ORCHARD OF C. G. WINN, GRIGGSVILLE, 1913 SPRAY DATES Three summer applications were made upon the following dates: April 21 to 23; May 6 to 9, and May 20 to 23. RELATIVE VALUES OF LIME SULFUR AND BORDEAUX Experiments at Griggsville during 1912 showed lime sulfur and Bordeaux to be equally effective in the control of scab.1 The apples sprayed with lime sulfur had higher color and finish and the foliage was more vigorous than where Bordeaux was used. The comparison of these two sprays was continued in 1913, however, to gain further information regarding the relative values of the two sprays. Two plats were treated as shown in Table 17. JJ, C. Blair et al., 111. Agr. Exp. Sta. Bui. 185, p. 176. 460 BULLETIN No. 206 [April, EFFECT ON FOLIAGE The foliage of the unsprayed plat as well as that of both sprayed plats was free from scab during the entire season. The foliage of the plat sprayed with lime sulfur was more vigorous than that sprayed with Bordeaux. The former plat was practically free from spray in- jury, while on the latter plat considerable spray injury appeared late in September in the form of brown spots. Both plats showed a slight amount of leaf spot (Spliceropsis malorum), but a comparison with the infection present on the unsprayed trees shows that the sprays were reasonably effective in controlling this disease. EFFECT ON FRUIT The apples from these plats were picked and examined September 30. The results are given in Table 17. The comparative fungicidal values of lime sulfur and Bordeaux were less conclusively shown than had been hoped for, because fungous diseases were present in only small amounts. Both sprays gave perfect control of scab and sooty blotch. Plat 1, sprayed with Bordeaux, showed even more damage from codling moth than the unsprayed plat and four times more than Plat 2, sprayed with lime sulfur. It is believed, however, that this was due to uneven infestation rather than to the effects of the treatment. Curculio injury was reduced from 67.83 percent on the unsprayed plat to 21.94 percent on Plat 1, and to 10.3 percent on Plat 2. The most important difference between the effects of these sprays upon the fruit is shown in the amount of russet recorded. There was 64 percent serious and 26.5 percent slight russet on the fruit from trees sprayed with Bordeaux, as compared with .5 percent serious and 3.05 percent slight russet on the fruit from trees sprayed. with lime sulfur. However, the amount of russet recorded for the unsprayed trees was .66 percent serious and 2.5 percent slight; hence it may be concluded that lime sulfur was not responsible for the russet on the trees sprayed with that material, and that 63.34 percent serious and 24 percent slight russet, in Plat 1, can be attributed to Bordeaux injury. The grade percentages show that the plat sprayed with lime sulfur produced 48 percent No. 1's, 23 percent No. 2's, and 29 percent culls, as compared with 9 percent, 15 percent, and 76 percent of the same grades, respectively, produced by the plat sprayed with Bordeaux. The latter plat had fewer No. 1 's and more culls than the unsprayed plat. These differences were due to Bordeaux russet. The apples sprayed with lime sulfur had excellent color and finish at picking time, and were of good size. Those sprayed with Bordeaux, on the other hand, lacked color, and were very small, badly russeted, and distorted. 461 ^J OiOO ». ^ OlO CO O OO 43 ^ 43 iO CO 00 lO O5 ^O 4* _bC COCO IN •4-J .SP COCO TiH CO Tj< tN O> CQ GO CQ IN D j & CQ m CQ (N CO O CO CO Q 3 Q 1 CO (N CO H 1 H j? •!•-§ •i CQ S-« ^ "* O CO O5COOO 4 q £ i o • i TO tj< O O CO O CO O5 CO I> i-H CO 00 g 13 ul eg* OO id l> O O iO O W CM 'O t>- b- 1 S "o S "2 CQ CO 1-H E 3 I CQ TH 1> rJH O O CO T-H t-- IO g .x O U O (N 3 C 5 •» (U 3 CQ H bC SJ ^ OJD H C3 -4-> G o *c * OOCO H -u G "o is OO O O O CO O O O O O CO *§ O rH 0) o (H o CQ CQ° 'co « CO 3 O o o CQ CQ° CO 2 J £ .1 8815 i C 3 2 3 « QO <2 1, So o o o »o O O O O IT— T-H 3 CO | CQ T-H ! a H 42 CQ O 0 0 CQ •i 03 OO 00 ooo i 1 h O CQ •c § O O O O O 00 §C5 CQ ° j a 1 &z ^ i i Ea D ^ § s 2 i § S 3 CO OS CO t^CNCO I i C f i < n a „ j co H CP 3 COCi 00 s G (N (N O 1 1 1 1 JERATK a o . CQ G O 3 CO CO ® ~ - COIN CO • G IN O> O "o ^ 1 o -2 a t- 2 5 •^C^GG"^*^G £ "S «§ 05 ol *" f < i 3 J illlliil^ S pq H s^ 1 i i | Q H q H III *j|f *J H is s i C 1 k §3 §33 § 03"^"^ •g l-fe pi 1 "2 §"§ g §"2 "2 l^3 PQ'rJ^ 01 3 jyyyyy^ffljjbi •< T" C 4 q <3 03 O 1 A -S »3 ^T"1 T™^ C^ D ( q i— 1 (N CO ^ 10 S — H 43 i PH q o i •< O 462 BULLETIN No. 206 [April, a o ££ w •< a s 1918] SPRAYING APPLE ORCHARDS IN 1913 AND 1914 • 46$ EFFECTS OF USING BORDEAUX FOR SOME APPLICATIONS AND LIME SULFUR FOR OTHER APPLICATIONS IN THE SAME SEASON'S OPERATIONS . The effect of using Bordeaux for some applications and lime sulfur for other applications in the same season's operations was made the subject of an experiment in which plats were treated as shown in Table 18. EFFECT ON FOLIAGE No scab appeared on the foliage of the sprayed plats during the entire season. A slight amount of spray injury appeared late in September, and also a light infection of frog-eye fungus (Sphceropsis malorum). In general, however, the foliage of these plats was vig- orous and healthy. EFFECT ON FRUIT The apples from these plats were picked and examined September 30 and October 1. The results are given in Table 1.8. These results show that all the sprayed apples were free from scab and that sooty blotch was almost perfectly controlled. The brood of codling moth entering at the calyx was well controlled in Plats 2, 3, 4, and 5. The irregular and inconsistent results shown in the control of codling moth entering at the side, mostly larvae of the late brood, indicate that three applications of spray made early in the season were in- effective in preventing damage by codling moth appearing late in the season. Curculio injury was greatly reduced by all the treatments. Here again the most important differences are brought out in the russet columns. Since the unsprayed plat showed .66 percent serious and 2.5 percent slight russet, the true effects of the sprays are deter- mined by subtracting the amounts of russet on the unsprayed trees from those on the sprayed trees. Thus we find that in Plat 3, Bor- deaux applied at the cluster-bud stage actually caused 6.46 percent serious and 22.33 percent slight russet ; that in Plat 4, Bordeaux ap- plied two weeks after the fall of the bloom caused 22.34 percent serious and 61 percent slight russet; and that in Plat 5, Bordeaux applied both at the cluster-bud stage and two weeks after the fall of the bloom caused 29.34 percent serious and 42.4 percent slight russet. These results indicate, then, that Bordeaux, under the conditions of this experiment, when applied either just before the bloom or within two weeks after the fall of the bloom, will russet the fruit. Russet greatly reduced the color and smoothness of the apples on all plats sprayed with one or more applications of Bordeaux. 464 BULLETIN Mo. 206 f April, £ ooo coo O Oi OO rH »O l^. •£f rH 00 t-- . OO Oi " ^ 5 • U 4 i 2 4 49 02 r-r o CO O CO -* o CD OO rH IO •* CN *O b- CO rH rH rH C^l 1 1 j 1 1 J. <£ CO O CO O O CNCO rH t> CO IO CN rH CD rH 3 i j H -d o -4;3 H o S i CO O CO CO CN O CO l> CO 00 OO rH O 00 rH CN CO 5 4 r Bfl J "o a bO 02 l> O O CD CO t^ "3 OO rH O CO IO OO1^ M* CD CO IO Tf< IO ^ rH rH 4 • 3 c. 03 i 13 O O O CO O O »OO O CO rH O Tt< (N IO ! rH 1 r-r-T 02 •i 03 « 0 o o o o o ooo O O O O O O iO GSVILL1 ' • u 03 1*3, So p, 3 O CN OO CO OO CO Oi CO CN CN CN rH CO CO CO ^0 q H -4 O 6 CO CO •**< IO 00 Is- CO CN CN CN -* rH rH rH d 3 1 3 f S o H rH 6 55 CN Oi CO t^- Oi ^^ rH Q j S 5 _ 1 O- v co G O co co co co co co o - G CN CN CN CN CN CN O J H 9 9 9 £ 9 9 J Q 3 3 | G G G G G G o3 o3 o3 o3 o3 03 - G G G G G G Q H J 03 2 H 3^ 3"§ 3^ 3T3 %-0 %~Q S II 3^-9^-3^3^-3^3^-g ^ 3 a a a a a a o ^ 4 4 I H ^03 O rH CN CO T}< IO -g 6 1918} SPRAYING APPLE ORCHARDS IN 1913 AND 1914 465 RELATIVE VALUES OF PASTE AND POWDERED ARSENATES OF LEAD The standard brands of arsenate of lead used in the spraying ex- periments previous to 1913 were in the paste form. Such powdered arsenates of lead as had appeared up to that time had not proved satisfactory. In 1913 a new powdered arsenate of lead, Corona dry, showed promising qualities in laboratory tests and was accordingly included in the schedule of treatments in the field tests. Plats were sprayed with powdered and paste forms, separately and in combina- tion with Bordeaux and lime sulfur, as shown in Table 19. EFFECT ON FOLIAGE The foliage of Plats 6 and 7 was very good thruout the season. It was free from scab, and showed only a slight amount of tip and edge burning due to the spray. Plat 8, however, sprayed with Bordeaux arsenate of lead (powdered), showed considerable spray injury late in the season. The foliage of Plat 9, where lime sulfur arsenate of lead (powdered) was used, was excellent. EFFECT ON FRUIT The apples from these plats were picked and examined October 2 arid 3. As will be seen in Table 19, all the sprayed plats were en* tirely free from scab except Plat 7, where an insignificant infection appeared. No scab or sooty blotch appeared in the plats where Bor- deaux and lime sulfur were used with the arsenate of lead. Very slight infection of sooty blotch occurred in Plats 6 and 7, where the paste and powdered arsenates of lead, respectively, were used alone. From the amount of infection present in the check plat, it would ap- pear that these sprays had exercised a beneficial fungicidal action. The brood of codling moth entering at the calyx was effectively reduced by both the paste and the powdered arsenate of lead. Con- trol of codling-moth side injury, however, was less effective. Both forms of arsenate of lead greatly reduced curculio injury, with no special advantage in favor of either. The plat sprayed with powdered arsenate of lead produced a larger percentage of No. 1 apples than that sprayed with paste ar- senate of lead, but the records of insect and fungous injuries indicate that other factors than the sprays were responsible for this result. Neither paste nor powdered arsenate of lead used alone appeared to cause spray russet ; there was less on the apples sprayed with these materials than on the apples in the check plats. The color, finish, and size of the fruit in Plats 6 and 7 were excellent. It is concluded from these experiments, therefore, that in every way the powdered form of arsenate of lead used (Corona) is as effective as the paste (Grassclli) with which it was compared. 466 BULLETIN No. 206 [April, Q *-t D IH O g £ eg S H > PH •/) PH O O O ug oO S "! CQ - Q H O ft W jg O CO O O CO OI-H lO CO O O OO i— 1 ^ bO . . .... O 55 tf -i 03 *< 3 ^ S CO CO O O O O O CO CO O O O i-l O ! CQ ° i.9 • i m 00 CD CO O O O CO O O CO O O OOCO 6"g « § »C 00 t^. CO (M Ot^ IO *O i^ CD i~^ ^O £ J3 "o 0) l^ CD CO CO CD O 1C 1C 1> OO CO CO O5l^ B s CQ O» O O OO O I> CM bO S< ex 3 X t>- OJ CO CO CO O CO oo co co 1-1 co coco -3 0) ^ O O O CO r-t t» CO • I— 1 '3 -a -g f.,, §IO o CO CD O O Tt< »O CO i-l i— I 1C •g CO N ^ V 3 CQ 1 1 -1^ o o CQ 'S * CQ 0 SO CD CO O O O O CO i— I O O »C o O O CO CD CO O 00 p 1 O OI-H i— i CD O O bO . . • • • . . a | CQ o CQ i •C 2j SO O O O OCO o o o o oco r n §-» iJ a O CD CO ^ iH i-l OJ 1C CD CO CO CO CO fc ra ,H OS O (N CO CO t^-O ( ii ° i— 1 1C (M ^ 03 "* N ii O, 0 S O CO CO CO CO CO CO i.2 ol •i CO to o co co t^ CM CO CO CD CO CM t» i— ( to CO -40 o a bO GO to o o to CO CO COCN i— i ! 1 1 S 09 | _a ^ o O > CO CO CO h- CO CO . CM CO lO y :-S _= CM t^ to O "O rt "o •"§ CO CO !>• to r» OJ _2 a GO O i-H CO COCM "cL, bC C- a ^ CM O O CO CO x ^o (^ CD O O i— 1 CO T3 o *c3 CN i-l CO J4 O 0 o '5. ^ -40 3 -40 bC 0 0 0 0 to "o *^ ' *O CO. to 00 O lO - sj O i— 1 i— I CM CN i— 1 D o o •H i— i 6 CM CM CO CO CM ^ CO a o CO CO CO CO O> of of CM" CM" o •«! ° 8 i— r i-T i— c i— i ^ • W W W CU CO CD QJ •g 'S "o ^ 0) 0) -40 03 CD "*~* "*^ a 0) Is "S g g a 9 ^ c3 ^ — ^ (^ ^ " — ** M H *+3 > tH ^^S >^ s 2 "§) ^ o ^3 '5)3 § "^ 0^ ^x 02 ^2* x ^t1 . ^- LL •^ ^O O O ^5 s s a j o CQ CQ >-J J ^ -*-* « _o3 iO CO t^ 00 g PH 6 470 BULLETIN No. 206 [April, RELATIVE VALUES OF LIGHT AND HEAVV: APPLICATIONS OF BORDEAUX ARSENATE OF LEAD AND LIME SULFUR ARSENATE OF LEAD To determine the relative values of light and heavy sprayings of Bordeaux arsenate of lead and lime sulfur arsenate of lead, four plats were sprayed with these materials as shown in Table 23. EFFECT ON FOLIAGE The foliage on the sprayed plats was free from scab but showed a little frog-eye fungus. Late in the season Plats 25 and 26 suffered somewhat from a spray injury which took the form of brown spots. Plats 27 and 28 had healthy foliage and were free from spray injury. EFFECT ON FRUIT The apples from these plats were picked and examined October 9 and 10. The results are given in Table 23. The fruit from all the sprayed plats was entirely free from scab and sooty-blotch fungi. Plats 27 and 28, sprayed with lime sulfur arsenate of lead, showed almost perfect control of codling moth entering at the calyx, whi'e Plats 25 and 26, sprayed with Bordeaux arsenate of lead, showed con- trols of 28 percent in the lightly sprayed plat and 73 percent in the heavily sprayed plat. The records of moths entering at the side of the apple are not considered significant because of the failure to apply sprays for the later broods. Curculio injury was reduced on all plats ; in the case of the Bordeaux-sprayed plats, the reduction was larger on the heavily sprayed plat, while of the plats sprayed with lime sulfur, the reduction was inconsistently less on the heavily sprayed plat. While no decided differences were shown between the effects of light and heavy applications in the control of fungi and insects, nota- ble differences in the amounts of russet were observed. Heavy appli- cations of Bordeaux seriously russeted 68.25 percent of the apples as compared with 26 percent seriously russeted by light applications. As the spray was applied with a hand pump at pressures not greater than ]25 pounds, and as the same nozzles were used for both applications, the greater amount of russet can be attributed only to the greater amount of spray applied. Both of the plats sprayed with lime sulfur showed a negligible amount of russet. SUMMARY OF RESULTS AT GRIGGSVILLE, 1913 1. Owing to the small amounts of apple scab, sooty blotch, and other fungi which appeared, it was impossible to obtain conclusive results as to the fungicidal values of the sprays used. Both Bordeaux 1918} SPRAYING APPLE ORCHARDS IN 1913 AND 1914 471 arsenate of lead and lime sulfur arsenate of lead gave practically complete control of scab and sooty blotch. 2. Three applications of Bordeaux arsenate of lead caused con- siderable foliage injury late in the season, and very seriously russeted, stunted, and distorted the fruit. 3. Lime sulfur arsenate of lead had an invigorating effect on foliage and a stimulating effect on the color and finish of the fruit. 4. Some russeting occurred as a result of single applications of Bordeaux arsenate of lead, applied either just before or two weeks after the bloom. 5. Powdered arsenate of lead gave as good results as the paste arsenate of lead. 6. Arsenate of lead used alone stimulated color and gave the fruit a good finish. 7. Various strengths of homemade lime sulfur, containing 2, 4, 6, 8, and 10 pounds of sulfur, together with 4 pounds of arsenate of lead to 100 gallons of spray, all gave satisfactory results. The 12- pound strength caused considerable injury to the foliage. 8. Copper ferrocyanide made in different ways proved useless as an insecticide when used alone. 9. Thomsen atomic sulfur arsenate of lead and Grasselli lime sulfur arsenate of lead gave equally good results in the control of fungi. Niagara soluble sulfur with arsenate of lead caused very seri- ous foliage injury but gave highly Colored fruit and satisfactorily controlled scab and sooty blotch. 10. Light spraying with Bordeaux, using 115 to 125 pounds pressure, caused less serious russet than heavy spraying at the same pressure. 11. Light and heavy spraying with lime sulfur arsenate of lead gave equally good results except in the control of curculio, for which light applications were more effective. 472 BULLETIN No. 206 [April, SPRAYING EXPERIMENTS IN 1914 AT GRIGGSVILLE, PIKE COUNTY BY ALFRED J. GUNDERSON OBJECTS Spraying experiments were conducted at Griggsville, in 1914, to study the following points in summer spraying: (1) the relative values of lime sulfur and Bordeaux; (2) the value of interchanging lime sulfur and Bordeaux; (3) the value of a drenching spray, ap- plied at the dropping of the petals, for the control of codling moth ; (4) the relative values of light and heavy applications of lime sulfur arsenate of lead and Bordeaux arsenate of lead; (5) the relative val- ues of light and heavy applications of lime sulfur arsenate of lead and Bordeaux arsenate of lead when used interchangeably; (6) the effect of reducing the strength of lime sulfur in the sprays following the second application ; (7) the value of a fourth summer application ; (8) the relative values of certain brands of arsenate of lead; (9) the relative values of certain proprietary lime-sulfur compounds; and (10) the fungi cidal and insecticidal values of copper ferrocyanide with and without acetate of lead as an accelerating solvent. LOCATION AND DESCRIPTION OF ORCHARD The same block of trees was -used in these experiments as that used in 1913, described on page 458. The arrangement of the plats is shown in Fig. 5, page 459. APPARATUS AND MATERIALS The sprays were applied with a Morrill and Morley Eclipse power sprayer at about 150 pounds pressure. Friend disc nozzles were used except for the second application on Plat 7, for which Bordeaux noz- zles were used. Unless otherwise stated in the following tables, the sprays were prepared according to the methods described on pages 430 and 431. WEATHER CONDITIONS The weather from the middle of April thruout the summer was dry. During the fall, however, there were frequent rains. The tem- perature was exceptionally high during the summer months and early September. Effect on Fungi. — The season was most unfavorable for fungous development. No scab infection appeared on any of the plats because of the dryness of the spring and early summer. Only a small amount of sooty blotch developed during the damp fall weather. 1918] SPRAYING APPLE ORCHARDS IN 1913 AND 1914 473 Effect on Codling Moth. — Under the hot, dry conditions prevailing during the summer, a second brood of codling moth appeared, and following it a partial third brood. Larvae from this third brood be- gan to enter the apples about the middle of September and continued doing damage up into picking time. In the experience of fruit grow- ers at Griggsville an attack of third-brood codling moth had seldom, if ever, occurred, and most certainly never before in the history of the experimental work at that place. Consequently such an attack was not anticipated, and no sprays were applied against it. Sprays had been applied, however, against both the first and second broods, and these broods caused only slight damage. The third-brood moths, no doubt, came* from a poorly sprayed part of the orchard not in- cluded in the experiments, in which large numbers of second-brood moths developed, producing a third brood that infested the experi- mental plats. It is recognized that from 75 to 85 percent of first-brood codling moth enter the apples at the calyx end; hence the data in these ex- periments showing the number of larvae entering thru the calyx would furnish an excellent criterion of the effectiveness of the sprays in controlling first-brood codling moths. Similarly, the number of larvae entering thru the sides of the apples would, under normal conditions, furnish an excellent basis for a comparison of the effectiveness of sprays in controlling larvae of the second-brood moths. Unfortu- nately, however, since the third-brood larvae also enter thru the sides, and since the attack of this brood was more serious than that of the second brood, such comparative results as might have been observed from the effects cf sprays on the second brood were largely obscured. While there are some small differences among the various plats in the number of moths entering thru the sides of the apples, these dif- ferences are not consistent nor large enough to be conclusive. In the case of the first brood, however, as indicated by the number entering thru the calyx, the results may be considered conclusive. Results showing the percentage of side injury done to apples by codling moth, tho given in the tables which follow, are not considered in the con- clusions. SPRAY DATES All plats, with the exception of Plats 14 and 1C, which were sprayed three times, received four summer applications. The dates of the applications were as follows : April 22 to 24, May 4 to 5, May 9 to 12, and July 8 to 10. RELATIVE VALUES OF LIME SULFUR AND BORDEAUX Experiments conducted at Griggsville during the previous tlmv years showed lime sulfur and Bordeaux to be equally effective in the 474 BULLETIN No. 206 . [April, control of fungi common to that locality. Furthermore, it was demon- strated that trees sprayed with lime sulfur arsenate of lead produced fruit of higher color and better finish and had bettev foliage than those sprayed with Bordeaux arsenate of lead. The effects of these two sprays were again compared in 1914, when two plats were treated as shown in Table 24. EFFECT ON FOLIAGE The leaves of the trees sprayed with lime sulfur arsenate of lead showed a slight amount of spray injury which appeared in the form of tip and edge burning. Spray injury caused by Bordeaux arsenate of lead appeared as small brown spots on the foliage. The foliage of the plat sprayed with lime sulfur arsenate of lead was denser and more vigorous than that of the plat sprayed with Bordeaux arsenate of lead, which suffered from frequent epidemics of yellow-leaf. EFFECT ON FRUIT The apples from these plats were picked and examined October 12, with the results presented in Table 24. These data show that, while the unsprayed fruit had 1.75 percent serious and 23.25 percent slight sooty blotch, both Bordeaux arsenate of lead and lime sulfur arsenate of lead completely controlled the infection. Sooty blotch was confined entirely to the unsprayed fruit hanging near the ground and was due to frequent fall rains, which created favorable conditions for the development of this disease. The unsprayed fruit had 10.25 percent calyx injury caused by first-brood codling moth; Plat 2, sprayed with lime sulfur arsenate of lead, had .75 percent of this injury; and Plat 1, sprayed with Bordeaux arsenate of lead, 1.25 percent. The check plat showed 23.25 percent serious curculio injury as compared with 6.75 percent on Plat 1 and 4.5 percent on Plat 2. A marked difference in the effects of the two sprays upon the fruit is shown in the russet columns. Plat 1, sprayed with Bordeaux ar- senate of lead, showed 24.75 percent serious and 61 percent slight russet, as compared with .25 percent serious and 3 percent slight rus- set on Plat 2, sprayed with lime sulfur arsenate of lead. Reference to the amount of russet on the unsprayed row will show that 1.25 percent serious and 2.25 percent slight russet may have been caused by something other than the sprays. Since these amounts were pres- ent on the unsprayed trees, the indications are that lime sulfur ar- senate of lead was not responsible for the russet recorded. By the same reasoning it would also appear that 23.5 percent serious and 58.75 percent slight russet in Plat 1 was caused by Bordeaux. The apples from the plat sprayed with lime sulfur arsenate of lead were the only ones affected by burning. This injury followed within two days after the fourth application, which was made July 8. 1918} SPRAYING APPLE ORCHARDS IN 1913 AND 1914 475 The temperature at the time of this application was 99° F. When first noticed the injury appeared as black, sunken areas the size of a half dollar, and was confined to fruit on certain limbs. Tho it seemed then that considerable injury had been done, by picking time only a small percentage of the fruit showed the effect of burning. Heavy applications of lime sulfur arsenate of lead applied as late ass July and August are usually followed by burning, especially if the weather is very warm. The absence of the pubescence character- istic of apples earlier in the season permits the spray to run together over the smooth surface of the apples and collect in one spot. The material so collected dries quickly in hot sunlight and becomes so caustic that injury to the skin results. Heavy spraying has been safely done, however, as late as three weeks following the bloom, even during hot weather. The absence of any resulting injury was in all probability due to the pubescent condition of the fruit. Plat 2 was sprayed thoroly but not heavily early in July. In spite of 'the care exerted, some of the fruit received more material than was intended and some burn resulted. Plat 2, sprayed with lime sulfur arsenate of lead, had 65 percent No. 1's as compared with 51 percent in Plat 1, which was sprayed with Bordeaux arsenate of lead. Bordeaux russet was responsible for most of the difference. The apples sprayed with Bordeaux ar- senate of lead were poorly colored and had a rough finish, while those sprayed with lime sulfur arsenate of lead were highly colored, smooth, and waxy. VALUE OF INTERCHANGING LIME SULFUR AND BORDEAUX AS SUMMER SPRAYS In order to obtain additional information on the value of inter- changing lime sulfur and Bordeaux as summer sprays, plats were sprayed as shown in Table 25. EFFECT ON FOLIAGE The foliage of Plats 3, 4, and 5 showed a small amount of spray injury in the form of brown spots caused by the Bordeaux and as tip and edge burning caused by the lime sulfur. All three plats suffered from an attack of yellow-leaf which slightly reduced the amount of foliage. EFFECT ON FRUIT The apples from these plats were picked and examined October 12, with the results presented in Table 25. Sooty blotch was perfectly controlled by all the sprays. Calyx injury from codling moth was materially reduced on all plats. The unsprayed row showed 23.25 per- 476 BULLETIN No. 206 [April, J ^r^ fi H pq >J I? co H 9 BO — E i PQ rt -3 o o a 0 o-e 00 COS , if a CO c » ssg CO ° CO 0 CO o &£' - fto.2 "H i 3 &cS § COOOrH rH-H^ (NrH ^ ~ o> coco a **»; w -— r2 ° 9^ ^g c3 a> fl £ »^C as| 3^-2 isl •Sg^3 S.§ o CQ^^; J! o +» 00 cos .£§ ro c4J C ro S 3 -n O •c § CO ° O S a: CD 3 CO ° O -3 o a* VD rt £ iO 8 8 812 CO 00 OrH co CO (H — « S -/-. o oe, go O (M (M !> o o o »c C CN 1C (M til "2. CO rH r "Si £ 1C 1C 1C S r^ + 2 • JM O 1^ 1— 1 ^ T « *1 fe OQ 0 0 rt CQ O 2 23 O H S« J 'B. "S ^ 0N o ooo gs oO g| fc "> CO ^ OO rH i-l §" PL. 6 t- ICO is P5 "^ a c3 2 CO 1C '-'O o H V, ^ t^ t^iC m M -o ^ CO t* ^ CO i-l i-l _g 3 00 ""!""! 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CD M H Iplpll l^loSl^l * 1* 6 6°l CQ J to t^ oo o PH N J3 O 488 BULLETIN No. 206 [April, FUNGICIDAL AND INSECTICIDAL VALUES OP COPPER FERROCYANIDE WITH AND WITHOUT ACETATE OF LEAD AS AN ACCELERATING SOLVENT The results of past experiments with copper ferrocyanide showed it to be practically useless either as a fungicide or as an insecticide. This ineffectiveness may be explained by the fact that copper ferrocya- nide is very insoluble. It was suggested that the addition of an accelerating solvent, such as acetate of lead, might make this com- pound sufficiently soluble to be effective. Accordingly, three plats were treated as shown in Table 33. EFFECT ON FOLIAGE The foliage of Plats 26 and 27 was by far the best in the orchard, from the standpoint of both color and size. The leaves possessed a dark green, velvety appearance. The foliage of Plat 28 was excellent but not equal to that of Plats 26 and 27. EFFECT ON FRUIT The fruit from these plats was picked and examined October. 21 and 22, with the results presented in Table 33. The absence of sooty blotch in Plats 26, 27, and 28 may have been due to the fact that these plats were situated on higher and drier ground than the unsprayed trees. Codling-moth calyx injury was almost equally reduced on Plats 26 and 27 by the action of the arsenate of lead. On Plat 28, however, this injury was not much less than on the unsprayed row. Curculio injury was effectively reduced on Plat 26. The greater in- jury from this insect shown in Plat 27 may be explained by the fact that this plat was situated near a clump of woods and underbrush. It has been, the experience of the writer that when even thoroly sprayed trees are situated in close proximity to a woods or a brush heap, they suffer more from curculio than those in the open. The sprays applied to Plat 28 reduced curculio infestation only slightly. Plats 26 and 27 had fruit of higher color and better finish than did Plat 28, probably owing to the arsenate of lead in the sprays. Plats 26 and 27 far surpassed Plat 28 in the percentage of No. 1 apples. Plat 28 and the unsprayed row had about equal percentages. SUMMARY OF RESULTS AT GRIGGSVILLE, 1914 1. Climatic conditions at Griggsville in 1914 were unfavorable1 to scab development but favorable to codling-moth infestation. 2. Codling-moth calyx injury was greatly reduced on all plats where arsenate of lead was used. Because of severe infestation from a partial third brood of this insect entering thru the jsides of the apples just prior to picking time, the effectiveness of the sprays in controlling second-brood codling-moth larvae was largely obscured. 1918] SPRAYING APPLE ORCHARDS IN 1913 AND 1914 489 3. Sooty-blotch infection was small ; it was completely controlled. 4. Serious russeting of the fruit resulted from Bordeaux applied about a week after the bloom. Some russeting resulted from the cluster-bud application of the same material, but none from an ap- plication made early in July. 5. Both Bordeaux arsenate of lead and lime sulfur arsenate of lead caused foliage injury, the former causing more serious injury than the latter. 6. Lime sulfur arsenate of lead applied on hot days early in July caused some burn. Early applications, however, did not. 7. Apples sprayed with lime sulfur arsenate of lead had better finish and color than those sprayed with Bordeaux arsenate of lead. 8. Interchanging lime sulfur arsenate of lead and Bordeaux ar- senate of lead, except when three applications of lime sulfur arsenate of lead were followed by one of Bordeaux arsenate of lead early in July, proved unsatisfactory, owing to the increased amount of russet. 9. A drenching spray under low pressure applied at the fall of the bloom proved unsatisfactory in the control of codling, moth. 10. The severity and the amount of Bordeaux russet depended upon the quantity of spray used. 11. A heavy application of lime sulfur arsenate of lead applied early in July caused more serious burn than a light application applied at the same time. There was no difference in this respect between light and heavy applications made earlier in the season. 12. Heavy applications of lime sulfur arsenate of lead and of Bordeaux arsenate of lead used interchangeably proved less satisfac- tory than light applications made at the same times, owing to the better color and finish of the lightly sprayed fruit. 13. No particular advantage was gained by gradually reducing the strength of lime sulfur in the applications of lime sulfur arsenate of lead following the second spraying ; l-in-20 homemade lime sulfur caused practically the same amount of burn as l-in-50 homemade lime sulfur when applied early in July. 14. Three applications of lime sulfur arsenate of lead proved more satisfactory than four applications of either lime sulfur arsenate of lead or Bordeaux arsenate of lead. 15. All brands of arsenate of lead tested reduced codling-moth injury effectively. 16. Niagara soluble sulfur, Grasselli lime sulfur, and Thomsen atomic sulfur combined with arsenate of lead caused some burning of the fruit when applied early in July. The soluble sulfur seriously injured the foliage ; the other two sprays caused but slight injury. 17. No data were secured on the fungicidal value of copper fer- rocyanide with and without acetate of lead. The data on the in- secticidal value of this spray indicate that it is too slight in effect to be of commercial significance. 490 BULLETIN No. 206 [April, GENERAL SUMMARY BY B. S. P1CKETT The field experiments in spraying in 1913 and 1914, having been performed with a view to solving certain definite problems, are sum- marized in the form of answers to specific questions suggested directly or indirectly by the general considerations discussed in the introduc- tion to this bulletin. SUMMARY OF DATA 1. What is the general effectiveness of applications of standard spray mixtures, including Bordeaux, lime sulfur, and arsenate of lead, in the control of fungi and insects affecting the apple crop? In summarizing the data for the field experiments during the years 1909 to 1912,1 the writer, in answering a similar question, made the following .statement : "No fact stands out more distinctly in a study of the data presented in the reports included in this bulletin than the general effectiveness of spraying over no spraying. Even under the most unfavorable circumstances, some degree of benefit has resulted from the application of all the standard sprays in every series of experiments and in every year of the experimentation. Year after year the sprayed plats have been conspicuous by their more healthy and vigorous foliage and by the freedom of their fruit from insects, and diseases." The data obtained in 1913 and 1914 add further evidence of the effectiveness of spraying, tho the comparative freedom of some of the orchards from fungi and of others from codling moth and curculio, in one or both seasons, has resulted in obtaining fewer records than had there been more generally severe infestations of insects and in- fections of fungi. Tables 34 and 35 present a summary of all the data obtained in 1913 and 1914 which bear directly on the effectiveness of Bordeaux, lime sulfur, and arsenate of lead in controlling fungous diseases and insects. At a casual glance it will be seen that in nearly all cases high degrees of control of diseases and insects prevail. In interpre- ting the data, however, allowances must be made for the severity of the disease infection or the insect infestation, as the case may be. When such allowances are made, the advantages of spraying become even more marked than the controls in the tables indicate. No data on the control of apple scab or other fungous diseases where either Bordeaux or lime sulfur with arsenate of lead were used were secured at Neoga or Flora. At Neoga, apple scab did not appear during 1913 and 1914, and at Flora no tests were made of either spray alone. At Griggsville, in 1913, there was a small infection of apple *J. C. Blair et al., 111. Agr, Exp. Sta. Bui. 185, p. 187. SPRAYING APPLE ORCHARDS IN 1913 AND 1914 491 Percentage of — B PQ O OOOOOiOO»O ed to Plat 7 in standard quan- made in standard quantities; se records for Plat 2 are pre- e fact that the amounts varied, id burn data are obtained by plats in question. C^ 00 1— c Russetc O 1-H »O CO O • -OOO 000000 -OS "3-2 o o o "o 3 Control CO O O5 O5 2 -S CO CO ^ co J§ C'43 OOO OOCOOOO CO CO O O O O CO (N ifg |J| Ml ii§ &** « »*• III Ifi |ii ^ O IO 00 (NCNIM (N (M (N CO *•»'-»>•£ »•»••< -s ^ ^ GO 00 S» O 00 O> O OJ ©©QOCOCOOOtOCpcOiO1'?1'?1/?^1'^*^©^© rt rt i^H CO •-( IO bCbCbCMtJOfcC'bCtJCfcCbCbCbtbCbCbC O O O C O O ^ OCbCtCtEbJC to to to to to W^'E'C'iH'E'E ti (-i U ^ 'G'S'C'C'C'G'C ££££££^0000000000000000 ^^^•^"^0000000000000000 r— a; s ^ S S •=§^•-§• § S 2 § ^ ^ • - -^ • 1918] SPRAYING APPLE ORCHARDS IN 1913 AND 1914 493 scab amounting in one check plat to 1.41 and in another to 2.33 per- cent of the crop. Both Bordeaux and lime sulfur, when used sep- arately, completely controlled the disease except in one plat, where lime sulfur exercised a control of 89 percent. The total amount of scab in this plat amounted, however, to only .16 of one percent of the crop, an amount wholly negligible from a practical standpoint. In 1914 no apple scab appeared at Griggsville. Sooty-blotch infections running from 5 to 22.74 percent in 1913 and from 8.5 to 25 percent in 1914 were recorded for the check plats. Both Bordeaux and lime sulfur, however, when used separately, completely controlled this dis- ease in both seasons; Using Bordeaux and lime sulfur for different applications in the same schedule also gave excellent results in controlling fungous dis- eases. At Flora in 1913, where there was a serious infection of scab, amounting to 34.9 percent in one check plat and 62.2 percent in an- other, the combined sprays exercised controls running from 86 to 100 percent. With blotch the results were more variable but of decided importance. The infections in the check plats were 52.6 and 56.6 per- cent respectively, while the controls varied from 43 to 93 percent. At Griggsville, where there was a slight infection of scab in 1913, the combined sprays resulted in completely controlling the disease, while at the same place from 95 to 100 percent control of sooty blotch was obtained in 1913 and 1914. Codling moth and curculio, as a rule, were well controlled by ap- plications of arsenate of lead. Table 35 shows that in the entire series of experiments, the control of first-brood codling moth in the most effectively sprayed plats ranged from 78 to 100 percent. In nineteen cases out of twenty-three the control was above 90 percent. Even among the plats least effectively sprayed in each series, controls rang- ing up to 91 percent were obtained. In a single instance in the Griggs- ville experiments in 1913 one plat failed to show any control as a result of spraying, but the check-plat infestation was only 2.5 percent, and the difference between the check and the sprayed plat was but a fraction of one percent. Moreover, the most effectively sprayed plat in the same series showed a control of 100 percent. Later broods of codling moth proved much more difficult to con- trol ; nevertheless, in the most effectively sprayed plats, controls rang- ing from 40 to 97 percent were obtained, while in the least effectively sprayed plats the controls ranged from -8 percent to 82 percent. In only one plat in one series did the sprays show no positive effective- ness in controlling late-brood codling moth. No data on curculio control were obtained at Neoga or at Flora, but many records were made at Griggsville, wrhere the infestation was sufficiently serious in both 1913 and 1914 to afford excellent opportu- nity for good comparisons. In 1913 the most effectively sprayed plats 494 BULLETIN No. 206 [April, showed controls ranging from 60 to 94 percent and the least effectively sprayed plats from 32 to 79 percent. In 1914 the most effectively sprayed plats showed controls ranging from 81 to 97 percent and the least effectively sprayed plats from 45 to 87 percent. In no case did spraying with arsenate of lead fail to exercise a decidedly beneficial effect. These results, taken in conjunction with those reported in Bulletin 185, establish even more firmly the advantages of spraying with stand- ard insecticides and fungicides, over no spraying, in controlling some of the more common insects and fungi affecting apples. 2. What are the relative values of Bordeaux- and lime sulfur as sprays for the apple? The relative values of Bordeaux and lime sulfur are dependent upon their comparative effectiveness as fungicides and their compara- tive liability to injure or improve the finish of the fruit and the health and vigor of the tree. In Bulletin 185 it was concluded (page 192) that "Bordeaux and lime sulfur, properly used, are both excellent sprays for the apple." A comparison of the effects of these fungi- cides in 1913 and 1914 may be obtained from a study of Table 34. It will be seen that, as fungicides, Bordeaux and lime sulfur were equally effective, 100-percent control being obtained in nearly every case. In their liability to cause injury to the fruit, marked differences between the two sprays appeared. At Griggsville, Bordeaux used alone caused russeting to a greater or less degree on from 50.75 to 92 percent of all the apples to which it was applied. No plats sprayed early in the season escaped the effects of the spray. On the other hand, lime sulfur rarely caused any russeting ; its range of injury was from .39 to 7.75 percent. Bordeaux caused no burning of the fruit, while lime sulfur in one case burned 2.5 percent and in another 18.5 percent of the crop. In qualities which contribute to an attractive .finish, such as smoothness, high color, and waxy skin, the fruit sprayed with lime sulfur was superior to that sprayed with Bordeaux. The only data recorded showing a comparison of the effects of Bordeaux and lime sulfur on foliage were obtained at Griggsville. In 1913 the two sprays were equally effective in controlling leaf spot (Sphceropsis malorum), the only disease which appeared (page 460) ; in 1914 the absence of diseases afforded no opportunity for compari- son (page 472). In both years the plats sprayed with lime sulfur had more vigorous foliage than those sprayed with Bordeaux (pages 460 and 474). When all the facts are taken into consideration, it is concluded that both Bordeaux and lime sulfur are efficient fungicides; that neither is always free from injurious effects to the fruit and foliage ; that lime sulfur used for sprays before July 1 is io,=s liable to injure fruit and foliage than Bordeaux; that lime sulfur used after July 1, JD18} SPRAYING APPLE ORCHARDS IN 1913 AND 1914 495 or during excessively hot weather, is more liable to injure the fruit than Bordeaux ; that lime sulfur used thruout the season is safer than Bordeaux ; and, finally, that the most desirable practice is to use lime sulfur for all the applications made in April, May, and, during cool weather, in June, and Bordeaux for applications made in July, or to omit the fungicide entirely from the July sprays, unless the season is very favorable for the development of bitter rot or other fungous diseases. 3. Are there differences between various brands of arsenate of lead which would make one brand more efficient than another? Table 36 presents a summary of the effects of the different brands of arsenate of lead used in 1913 and 1914. Owing to the variation in the number of tests of the different kinds and to the seeming varia- tions in the effects of several of the brands themselves, it is difficult to draw very definite conclusions as to their order of merit. Among the brands that gave rather distinctly inferior results were Grasselli dry, Hemingway paste, and Vreeland dry arsenates of lead. Ans- bacher paste arsenate of lead, which was used in one experiment only, gave excellent results in the control of first-brood codling moth and curculio, with a somewhat inferior control of second-brood codling moth. Grasselli, Sherwin-Williams, and Thomsen triplumbic paste arsenates of lead were somewhat inconsistently variable in their ef- fects, giving high degrees of control in some experiments and rela- tively low in others. The results indicated an average efficiency. In the experiments at Griggsville, Grasselli paste arsenate of lead gave better results than Sherwin-Williams paste arsenate of lead, while in the experiments at Neoga the results were reversed. Corona dry, Dow paste, and Sherwin-Williams dry arsenates of lead gave the most con- sistently good results of any of the brands used; each of these was tried at Neoga and Griggsville with closely corresponding effects: 4. Of what value are certain new and proprietary fungicides? The new and proprietary sprays tested were copper ferrocyanide, calcium hyposulfite, Thomsen atomic sulfur, Niagara and Grasselli soluble sulfur, and Sherwin-Williams tuber tonic. The effects of these sprays in comparison with the average effects of Bordeaux and lime sulfur are shown in Table 37. According to these results, the effects of copper ferrocyanide were not unfavorable. The complete absence of fungous diseases in some cases and the presence of only light infections in others, however, pre- vent drawing definite conclusions regarding the efficiency of the spray. The fungicidal efficiency of calcium hyposulfite was not deter- mined, owing to the absence of fungous diseases at Neoga, where the spray was used in 1914. 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