Issued January 13, 1913. U, S;“DEPARTMENT OF AGRICULTURE. Ss BUREAU OF PLANT INDUSTRY—BULLETIN NO. 268. B B. T. GALLOWAY, Chief of Bureau. Bie, oh os ) METHODS USED IN BREEDING ASPARAGUS FOR RUST RESISTANCE. .NT6 BY J. B: NORTON, Physiologist, Cotton and Truck Disease and Sugar-Plant Investigations. WASHINGTON: GOVERNMENT PRINTING OFFICE. 1913, a Monograph Issued January 13, 1913. Uses DEPARTMENT OF AGRICULTURE. BUREAU OF PLANT INDUSTRY—BULLETIN NO. 263. E EZ B. T. GALLOWAY, Chief of Bureau. METHODS USED IN BREEDING ASPARAGUS FOR RUST RESISTANCE. BY J. B. NORTON, Physiologist, Cotton and Truck Disease and Sugar-Plant Investigations. WASHINGTON: GOVERNMENT PRINTING OFFIOE. 1913, BUREAU OF PLANT INDUSTRY. Chief of Bureau, BEVERLY T. GALLOWAY. Assistant Chief of Bureau, WILLIAM A, TAYLOR. Editor, J. E. ROCKWELL. Chief Clerk, JAMES E. JONEs. COTTON AND TRUCK DISEASE AND SUGAR-PLANT INVESTIGATIONS. SCIENTIFIC STAFF. W. A. Orton, Pathologist in Charge. H., A. Edson, J. B. Norton, and F..J. Pritchard, Physiologists. C. O. Townsend and L. L. Harter, Pathologists. W. W. Gilbert and H. B. Shaw, Assistant Pathologists. C. F. Clark, G. F. Miles, Venus W. Pool, Clara O. Jamieson, Ethel C. Field,and M. B. McKay, Scientific Assistants. i W. B. Clark, Assistant Chemist. H. W. Wollenweber, Expert. E. C. Rittue, Assistant. A.C. Lewis, L. O. Watson, and Joseph Rosenbaum, Agents. 263 : D. OF D. JAN 21 1918 GAD eee COPIES of this publication may be procured from the SUPERINTEND- ENT OF DocuMENTS, Government Printing Office, Washington, D. C., at 20 cents per cop LETTER OF TRANSMITTAL. U.S. DEPARTMENT OF AGRICULTURE, Bureau or Piant INDusTRY, OFFICE OF THE CHIEF, Washington, D. C., July 29, 1912. Sir: I have the honor to transmit herewith a manuscript entitled ‘“Methods Used in Breeding Asparagus for Rust Resistance,” by Mr. J. B. Norton, Physiologist in the Office of Cotton and Truck Disease and Sugar-Plant Investigations, and to recommend its publication as Bulletin No. 263 of the Bureau series. This paper deals with the methods developed in the selection, pollination, and breeding of asparagus at Concord, Mass. The work was done in connection with the rust-resistant asparagus breed- ing investigations being conducted at Concord by this Bureau in cooperation with the Massachusetts Agricultural Experiment Station. The author desires to acknowledge the assistance of Mr. C. W. Prescott, of Concord, Mass., who, since the beginning of the work, has done everything possible to aid the breeding work. Mr. Frank Wheeler, of Concord, Mass., together with many other asparagus growers from various sections, has given active assistance in the work. Respectfully, B. T. GatLtoway, Chief of Bureau. Hon. JAMEs WILson, Secretary of Agriculture. 263 . 3 CONT ENES: Page LES Ga EY 0 9S eee Bae chee STEN SE Raps Aesy 690 Si ay ag gt 9 aston Gl aa pArAaeBe Mcp eee ence stench ts oils tle lak hab ee ee louse g Wecwrrener armist tacAMeNieh oc cdl ons Deon tse ska el bco kee on semen. 9 Hailureot spraying methods in the Mast. 22.222. 2.. 2.0202. 2 cl. 9 Prewaoue aibomMpis ac DrOed Ineo o26 ssa % eS hs ok Poo eee 10 Massachusetts Asparagus Growers’ Association......................2...-. 11 Popes HMnIECRrYy WON Kes ee lor ane aan elated eee eee Se Se 12 Nair Gt bio disease een sere eso ares. Wome Seu he re 12 Mittect, Of tie CIseAse bart eaten rae sume ee eee ENE OS ae 13 Wollectign Omar ibbledeie soup at is. SS Sono ee ae Tae eee eS 14 ani ran NM ENM We stete etek ns soo nooo. So. eel Ses So, 16 Value oruniformity..2-222- 22... --- etree es ee seer ae cent ee ake 18 introduetion: of uncultivated’ species... 220-2 .2.-.... 222.2) s.c200 cas... 19 Bete UMM prieetetny amet taiatnis oe ea tees Cintas Boe ae Sate 2 Hana ee Soe wee areee ode 20 Jen SIU ah GUS Ae 73) 1000. (ec Me Se rua ee i a a a 20 GER SVEL DEEN 21) ETON (0) ata ie ee ee ey ag Hl Judging rust resistance..............-.----- ABS SNe SS rete day Mean nes 21 lecond Gi novect PAN. 1. sexes th a ees ae sac sek ets ental 22 Protection of select plants from frost....... ae ae Pe oe 22 Rust infection to secure select resistant plants........................... 23 WaUeeeigl FON ANGE cece. ts oases tek Saws ew iss ero ds 23 Moerdial stare ourexistant planta 2 .)..\ 2. -.-<2 52... liedces. ele 23 Relation of structure to resistance. 225 229.020. ea 24 elxtiom Of visor buresistgNCG.-.s.0..2628 2... het ss ssf bl. 25 LUBE Gi Ao os eae lo eh et 2 cS de ec 27 vo) DES BE Ae SAS RA SS par Ne ee 27 5 AC) | OV ATES bts as Se i SS oe Sele ea Mi ae eet OE Raa 28 Methods ot Hand pollination 52: -252s-cs05 2200 eac 20-6 s aches sk ue 29 WUE Ons ede tet ne Sh ee at Betas cia sateen oa taal 31 Meri O MS Ges ume PLOTOMY scan sea ee oss ee ee te ey oa Bail Wserolloicmonnyaas orcs prance cts See Oe nid he oR 32 Comelaom ein Giesiona i.e in a Bean oN Gael e ee eS 32 ID AUN LOPS TES, LGSA SEA ee eee a TG a Ge eee 34 Use of correlation studies in breeding work........................-. 35 Smonmtreed lines ol mate Agog 2c. io sso go eee Ne 43 SDS TEIOT Bn era Nai Cai US sel i Oriana a nat ane a 45 aera TSE MERISbAMER SS.) ees ya er Oe 50 PSS TTSUU Ve: 07 Ti CENTRAL el aCe ee ca eg ea 52 LENTTOUS Dynal eases OT Ty. = 2 IEA eg aa a 53 OE TLC Sie URS OPS SS 2 Nt a ANI UA UN a Ue aM os a 3 TSTSTEEL S12) PSE eli Says VAR AR Me a RM i ee ae 54. TAC 2 SEIS ee 3h aa RI IR Rg 54 JASE SSR eo 5. 2 Sa eR ES a ae i Vea SE 54 263 5 6 CONTENTS. sl Page Plans tor distributions: c 225 acces onsale eee een eE ecraciae sins os cet 55 Suggestions to breeders andi erowers. 2. .c.-ssersnacloameeei ees seine sae le 55 Rist Tesistamea ysis cts cats Mamonoth Prolific 223 2 jo! he toes = e)os sce = Moore & Simon, Philadelphia, Pa. 14 | Donald’s Elmira. ... ..-| Johnson &.Stokes, Philadelphia, Pa. 16))| Golossal 22 2% - 2). -_| J. M. Thorburn & Co., New York, N. Y. 18 | Rust Resistant... ..-| B. R. Tillman, Trenton, S. C. 20: |: Colossal... .22-< .| Jas. Barr & Sons, London, England. 22 | Perfection..... Hl. W. Buckbee, Rockport, Ill. 24 | Seedling.......-.-. .--| R. P. Wakeman, Southport, Conn. 26 | Late Argenteuil.--.-. ..-| Vilmorin-Andrieux & Co., Paris, Frange. 28 | Vick’s Mammoth.... ..-| James Vick & Sons, Rochester, N. Y. 30 | Sutton’s Perfection.. -| Sutton & Sons, Reading, England. 32 | Reading Giant..--- ate 0. 34 | Early Argenteuil.. ..-| Vilmorin-Andrieux & Co., Paris, France. 36 | Barr’s Canadian.....-.- -| Barr & Sons, London, England. 38 | Mammoth Emperor.........-. ..-| James Carter & Co., London, England. 40 | Barr’s Mammoth...........--. -| Jas. Barr & Sons, London, England. 42 | Columbian Mammoth White. . -| D. M. Ferry & Co., Detroit, Mich. Ag GOP eee Se ee aa ene eee SER SM Ree aE J. M. Thorburn & Co., New York, N. Y. BGvWihlite Germamecr tee ec oer e eect! Vilmorin-Andrieux & Co., Paris, France. 46)\ubiriort, Giant Wiite's <2 ,.a an as | Ne 9 0 CS MINS PCa aD Sen ae get (LES ee Ley Uk Salo Sl a 3 (Beisel octet 10 +1 $e es SENN Uo See areal fagr tea (AREAS ae! 1 oa IN eae Ne a 2 15 feel [ees 25 +2 UR SS EES er Seay eter ee | Si AD a A I Rh a a Pp ee eee 2 +3 apse ge ear Nymcl F aaa | Ute gt BELO LIES OT a ets a PUR EN LR pH Fee 1 1 +4 Frequency ....... 4 3 4 7 9 5 14 24 10 1 81 Departure from mean.-| —5 | —4] —3 | —2) —1 C0 ce The greatest deviations are in the middle grades, but as these plants are not valuable for breeding parents the high correlation between the grading in the two, sets of observations from a practical standpoint is higher yet. This method of checking up the value of grades as- signed in selection work where the personal equation largely enters should be followed more extensively than it is at present. The ability to accurately judge differences of minor degree adds greatly to the value of the work. RECORD OF SELECT PLANTS. In making selections some permanent record is necessary. Perma- nent stakes in the field are not desirable, on account of the spring cultivation with a disk harrow. In our experimental plats the plants are placed at definite distances apart and a record made of a select | plant, giving its row number and plant number to enable it to be relocated in the spring. Four-foot lath make cheap and convenient stakes which can be seen for some distance in the field. When plants in a cutting bed are to be left for seed, it is necessary to mark them so the cutters will let them alone. PROTECTION OF SELECT PLANTS FROM FROST. On account of late frosts occurring after the selected plants are up a foot or so, it is sometimes necessary to cover them over night. Manila paper bags are very good for this purpose. When the shoots were covered with moist earth at times when the temperature went low enough to make ice one-fourth of an inch thick, the stalks froze and when the sun came out they thawed out rapidly enough to be killed. At the same time the shoots under the manila bags escaped injury. A peculiar frost phenomenon was observed in June, 1910, when a light . 263 SELECTION. 23 frost occurred in the lowest portions of one of the breeding fields. Glassine paper bags, which are used to cover flowering branches on female plants in breeding work, instead of protecting the flowers from frost actually increased the injury, so that the flower buds dropped off under the bags, while the unprotected buds outside remained uninjured. RUST INFECTION TO SECURE SELECT RESISTANT PLANTS. During the past three seasons there has been an abundance of rust during July, August, and September on the experimental grounds at Concord. This abundant attack of rust is necessary to obtain selec- tions of any practical value. The attack of rust should deaden the tops of practically 95 per cent of the young seedlings from standard Argenteuil stock in the seed bed, or in its ravages in a commercial field of good Argenteuil make it possible for a beginner to pick out less than 10 resistant plants per acre as being plainly superior in rust resistance to the other five or six thousand. So far in this work no asparagus plants have been found that will not rust to some extent. There is a wide difference in susceptibility in different varieties. The old American sorts represented in Con- cord by Moore’s crossbred are practically nonimmune, while Argen- teuil and other related European varieties are highly immune, so much so that they are not troubled by rust unless a new bed planted near by is not being cut in the spring. . There is no question that the spread of the rust from one field to another depends on the direction and intensity of air currents. On. the experimental field at Concord the prevailmg winds are from the northwest. This fact, combined with the circumstance that the dew dries up last on the northwest side of the plant, makes the heaviest attacks of rust on the shady side. On account of the direction of the prevailing wind at Concord, it is highly advisable to have any infec- tion area on the north or west of the seedling bed to be infected. Once a field has had a good infection of rust and the resistant plants marked, it is not necessary to provide rust in future seasons, as the select plants can be tested by growing pedigree seedlings. In fact, it is not necessary to test the individual resistance of a plant in order to determine its value as a breeding parent. All that is necessary is to test a small lot of its seedlings. CAUSES OF RESISTANCE. Aicidial stage on resistant plants —An interesting feature of the rust-resistant breeding work developed in the spring of 1909, when the cluster-cup stage of the rust appeared. The plants that had been selected as rust resistant in 1908 were allowed to grow without being 263 24 BREEDING ASPARAGUS FOR RUST RESISTANCE. cut. In addition to these selected plants several nonresistant plants were allowed to grow up to be used in crossing tests to determine the dominance of the resistant character. No uniform differences in the zecidial infection could be noticed, many of the most resistant plants having a better infection than the rusty plants. This development caused some doubt as to the nature of resistance and made it seem possible that the immunity of the year before might be due to some temporary factor. Later in the season when the summer stages of the rust appeared this doubt was dissipated, as the resistance again appeared in the select plants of the year before in about the same degree as in the previous season. Relation of structure to resistance.—The fact that sporidia from ger- minating teleutospores can infect through the epidermis without necessarily entering through the stomatal openings gives an explana- tion for the phenomenon just noted and sheds a possible light on the cause of rust resistance in asparagus. It is a well-known fact that in the hetercecious rusts the ecidial stages occur on plants widely different in general character from their hosts when in the uredo or teleuto stages. Thus there is reasonable ground on which to oppose the theory that rust resistance is due to structural differences simply because the ecidial stage appears on resistant plants as freely as on nonresistant ones. However, the theory that in asparagus resistance has a morphological cause is reen- forced by several other points. While little work has been done on this problem in asparagus, the evidence tends to show that resistant plants have smaller stomata than the nonresistant ones. It may be, of course, that the size of guard cells is not closely correlated with the actual size of the opening through which the mycelium must pass, but it gives a suggestive poimt of attack in solving the problem. When the rust develops in a field in summer, the shoots that came up first and have fully matured and hardened develop a lighter attack of rust than the shoots which appear during the’height of the rust epidemic. Once the rust gets started in the plant it goes ahead in its development equally well in resistant and rusted plants, no difference being discernible in the type or vigor of the individual sori on plants of different degrees of resistance. Ward,! in his studies of rust resistance in the genus Bromus, comes to the conclusion that resistance is not due to structural causes. He says: ? We are hence driven to conclude that the factors which govern predisposition on the one hand and immunity on the other are similar to those which govern fertility and sterility of stigmas to pollen * * *. 1 Ward, H. M. On the Relations between Host and Parasite in the Bromes and Their Brown Rust, Puccinia Dispersa (Erikss.). Annals of Botany, vol. 16, 1902, pp. 233-315. 2 Ward, H.M. Opcit., p. 314. 265 SELECTION. *. 5 Tn a later study of rust resistance Ward! says tha this researches “clearly led to the conclusion that the matter has nothing to do with anatomy, but depends entirely upon physiological reactions of the protoplasm of the fungus and of the cells of the host.” Until sufficient evidence has been accumulated on the correlations between structure and rust resistance in asparagus the writer does not care to claim definitely that the size of the stomata is related to the phenomenon of resistance to the attacks of the uredo stage of the asparagus rust. The presence of the ecidial stage on the asparagus plant gives a point of attack in the search for the cause of immunity that is not found in the hetereecious rusts of grasses, and when the studies on this point have been completed it is hoped that new light, at least, will be thrown on the question of disease resistance. Relation of vigor to resistance.—The theory that vigor of growth is correlated with resistance, as suggested by some American writers on the subject, can not be accepted, for many resistant plants are quite small and never produce strong shoots. The trials of the last two seasons of two equally resistant strains of Argenteuil stock from local growers at Concord show no relation between resistance and vigor. About 450 one-year-old seedlings of each strain were planted in 1908 side by side on uniform land and under uniform treatment. When they were cut for a short time in 1910 each day’s yield was separated into giant and common grades, using the local grading system. One lot gave a total yield over a period of 35 days, from April 23 to May 28, of 142,% pounds divided into 1063% pounds of giant and 353 pounds of common. The second lot gave in the same period only 6512 pounds total cut divided into 144 pounds giant and 51,5; pounds common. The details of the record are presented in Table IV. 1 Ward, H.M. Recent Researches on the Parasitism of Fungi. Annals of Botany, vol. 19, 1905, p. 21. 2638 56 BREEDING ASPARAGUS FOR RUST RESISTANCE. Tasie IV.— Yield from five 300-foot rows of Argenteuil asparagus, showing comparison of large and small strains, seasons of 1910 and 1911. Large strain. Small strain. Giant. Common. Giant Common. Date. Weight. Weight. Weight Weight. na : a2) wa a “a Da A 5 alelelele/elelal4/eiel 4 i) 5 8 5 3 8 i) 5 8 ° =) sg a (o) io) a (2) n Ay ) nN oy fo) nD : 1910.1 Apri i Doe tee Pah tealarareiatal 1 14 20 0 8 15 0 0 0 0 a 20 Va TEND SS aa a are 1 13 20 0 9 19 0 8 a 1 3 29 Dikizea | FR AEE Ad Ce 5 10 55 2 8 57 0 13 11 2 1 61 = 7 SSA a Ngee ptr eh 6 2 63 1 4 34 0 10 9 2 1 76 ay: i) hs Bd nei Ree vate eve 14 7 126 2 8 65 il 14 23 6 5 182 AR ETS OR SPAR Ga Shi seie ae 7 0 73 2 2 45 1 9 20 2 8 60 IG) ae eee cee ls eke Mes 5 i 45 1 4 29 0 12 9 it 11 41 ASPs Shes aie Re he il 6 96 3 2 73 0 10 9 4 4 135 Z 10 70 2 5 74 1 5 16 3 12 120 8 3 72 2 6 66 1 14 25 4 7 142 4 2 38 1 5 35 0 15 12 2 15 91 4 10 45 2 10 66 0 10 8 2 13 108 6 1 55 2 4 60 0 13 10 3 13 123 4 10 42 6 2 54 0 7 6 2 14 101 6 15 71 3 1 90 0 8 ff 4 2 146 3 12 40 1 6 48 0 if 6 2 3 85 2 15 Sills oe 5 51 0 8 6 1 9 50 3 4 31 1 15 55 0 5 4 2 69 106 13 1,073 35 12 936 14 8 188 51 i) 1,739 0 11 10 0 5 10 0 2 2 1 0 32 6 10 71 3 iG 82 1 8 22 4 7 153 8 9 82 3 8 85 1 4 15 5 0 133 15 5 127 3 12 86 2 8 28 8 10 208 21 8 189 4 8 105 4 1 51 8 10 233 25 (Olea ul 3 6 84 4 4 50 di 10 214 16 10 142 2 13 61 2 12 30 5 11 147 12 3 99 1 8 Al 2 8 34 2 2 65 8 1 72 2 0 45 2 11 33 2 11 80 10 13 89 2 if 61 2 iE 25 4 8 129 8 4 67 2 7 59 2 7 30 5 1 132 pA a] 3 83 2 10 62 1 9 18 4 12 132 8 3 74 2 13 80 1 10 18 5 11 146 6 0 58 1 7 33 1 6 17 2 14 78 1 10 103 3 8 88 2 9 27 i 10 192 8 9 7 5 1 117 2 11 28 9 5 246 8 5 74 2 8 69 2 0 23 5 4 161 1 3 13 0 10 20 0 1 1 0 9 23 8 14 79 1 10 42 3 6 39 4 0 112 < 14 72 1 13 44 2 13 34 4 0 108 13 9 121 5 1 113 3 4 38 8 3 224 9 7 89 5 10 140 2 10 33 5 13 184 7 4 60 4 13 125 1 5 16 4 8 128 5 6 48 3 3 7 1 11 19 3 14 101 Uf 0 60 3 5 83 i 11 21 6 3 176 6 6 53 2 8 67 0 11 9 3 12 114 8 2 80 3 6 98 1 10 20 3 3 108 4 12 48 2 11 67 0 11 9 1 15 49 6 4 62 1 13 56 1 6 18 3 6 104 5 9 51 1 14 55 2 0 23 3 14 113 3 0 30 1 3 37 1 9 20 2 12 103 5 14 59 2 9 67 1 7 20 3 10 105 i 10 67 4 4 111 1 15 23 5 9 164 4 0 40 3 5 88 1 13 20 2 1 50 4 12 47 1 1 20 1 2 16 4 74 137 2 13 30 1 11 48 1 3 15 2 6 70 305 10 |2, 737 100 6 |2,519 70 12} 845 164 10 4,654 1 Total yield in 1910: Large strain—2,009 stalks, weighing 142 pounds 9 ounces (average weight per stalk, 1.14 ounces); small strain—1,927 stalks, weighing 65 pounds 13 ounces (average weight per stalk, 0.54 ounce). 2 Total yield in 1911: Large strain—5,256 stalks, weighing 406 pounds (average weight per stalk, 1.23 ounces); small strain—5,449 stalks, weighing 2352 pounds (average weight per stalk, 0.69 ounce). 263 BREEDING. 27 The results in 1911, showing the yield for a full season, were more conclusive. Again lot 1 was far superior in size and total yield, giving 406 pounds total, of which 3053 pounds were of giant grade and 1002 pounds common. Lot 2, while actually producing more stalks in the season, had only 2352 pounds total, 70? pounds giant and 164% pounds common. The record for 1911 is also shown in Table IV. If there was any difference, the advantage in rust resist- ance is in favor of lot 2; moreover, about 10 of the best plants were reserved out of lot 1 as breeding parents and the cut is thus perceptibly reduced. Inthe region around Concord it has been noticed frequently that the poorer parts of the field had less rust when other conditions were equal, so that the application of chemical fertilizers has been held by some farmers to be the cause of the rust. BREEDING. The real work of breeding started in the spring of 1909. Many questions of importance in regard to methods had to be settled, for to a certain extent we were on unknown ground. Asparagus was generally recognized as a dicecious plant, but several writers and observers had suggested that parthenogenetic seeds were sometimes produced. The relative dominance of rust resistance in heredity was uncertain in asparagus. Biffen' in his work with disease resistance in the small grains had shown an apparent dominance of suscepti- bility, but in asparagus there is no question at present that the heterozygous forms are intermediate in resistance. The possibility of obtaining a combination between strains that would give first- generation hybrid vigor was important, and above all was the hope of finding two parent plants that would give a highly uniform progeny in rust resistance and vigor. In starting the work a study had to be made of the natural and artificial methods of pollination. Means had to be devised to control the pollination work so that reliable pedigrees could be established. The paragraphs that follow comprise an account of the observa- tions made and the resulting methods developed and now in practice on the different phases of these problems. SEX. Asparagus officinalis is functionally dicecious, but the flowers on both types of plants contain rudiments of the organs of the opposite sex. Under field conditions asparagus apparently requires the aid of insects to secure proper pollination. As a rule, no seed is set with- out the aid of bees and other insects carrying pollen from the flowers 1 Biffen, R. H. Journal of Agricultural Science, vol. 1, 1905, p. 40; vol. 2, 1907, pp. 109-128. 265 28 BREEDING ASPARAGUS FOR RUST RESISTANCE. of male plants to the stigmas of the flowers on the female plants. Hermaphrodite plants occur now and then, but so far in our experi- ments can not be considered a factor in seed production. In the flowers of the typical female plant the rudiments of stamens (Pl. VII, fig. 2) exists, but the writer has never seen one developed sufficiently to even suggest the possibility of self-pollination. On the other hand, the male plants often show a well-developed ovary with style and stigma and sometimes even a typical stigmatic surface. The great majority of male flowers, however, lack a well-developed ovary, the rudiment being about half the size of the normal ovary of the female flower and lacking any stigmatic development (Pl. VII, fig. 1), the style often being completely abortive. The hermaphrodite plants mentioned above are always of the male type, the flowers being for the greater part pure male in that they lack the complete and func- tional ovary. In one wild male plant examined the flowers at the extremities of the branches were typically female with well-developed stigma and abortive anthers. This male had been used for pollination work in testing rust resistance of select plants. Another hermaphro- dite plant which produced seed that would germinate and make healthy, vigorous plants had many flowers whose ovaries lacked the stigmas. The berries on these hermaphrodite plants are very small and rarely have more than one seed in them. The seeds are usually peculiar in that the seed coats are not entirely developed. The seeds appear mottled black and white, varying from the white of the uncovered endosperm in the smaller seeds to well-covered, entirely black seeds in which the coats have had their normal development and have completely covered the endosperm (Pl. IX, fig. 1). These small seeds make weak plants and in many cases abnormal ones, but the larger, better developed seeds make healthy seedlings of normal type. As yet these seedlings have not been observed in bloom, so the sex inheritance is unknown. POLLINATION. During the blooming period of 1909 and again in 1910 branches of pistillate plants were covered with paraffin paper bags to exclude pollen-carrying insects (Pl. VIII). Although more than a hundred of these check trials were made, in no case did any seed set from flowers that opened under the bags. The ovaries would swell and apparently start to develop good berries, but after reaching about one-third of the ordinary diameter they would turn yellow and drop off. The uncovered flowers on the same stem set seed abundantly (Pl. IX, fig. 2). That this failure to set seed is due to a lack of pollina- tion is shown by the large number of seeds secured under bags when 263 Bul. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE VII. Fic. 1.—MALE FLOWERS, THE LOWER WITH SOME OF ITS PERIANTH LOBES REMOVED TO SHOW THE STAMENS AND RUDIMENTARY OVARY. THE PERIANTH LOBES ARE LONGER THAN IN THE FEMALE FLOWER. X 5. Fic. 2.—FEMALE FLOWERS, THE UPPER WITH SOME OF ITS PERIANTH LOBES REMOVED TO SHOW THE OVARY AND RUDIMENTARY STAMENS. THE PERIANTH LOBES ARE SHORTER THAN IN THE MALE FLowers. X5. FLOWERS OF ASPARAGUS OFFICINALIS. Bul, 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE VIII FEMALE ASPARAGUS PLANT WITH BRANCHES COVERED BY “ GLASSINE’”? BAGS TO KEEP INSECTS FROM POLLINATING THE FLOWERS WITH POLLEN FROM UNKNOWN MALES, THIs PLANT BEING USED TO TEST THE COMPARATIVE RESISTANCE TRANSMISSION OF SEVERAL MALES. PLATE IX. Bul. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. ‘$335q Ad G3LVNITIOd 3Y3M ONY N3dQ 3HL NI G3WO001g S3HONVHYG YSMO7 “LNV1d IVWHON B3HL STIHM ‘NOSVAS ONINOOTG 3HL ONINNG G3ysAOD SVM V WOU ‘YF “LVOD G33S WOv1g 3HL 4O LuV 4O TIY SyOV7 W31L§ 3HL 40 dOL 3HL ‘NOILWNITIOd LNOHLIM SY3MO74 N314Q HOIHM G33S 3NO SNIVLNOD AYYSG HOVA ‘“LNVId ONIDOVG JO 103449 JHL ONIMOHS ‘W3LS SNovuVdsy—'S “dI4 BLIGOYHdVNYAH V WOYY ‘f ‘0339 GNV LINNy SNOVvYVdsSy—'} “dI4 PLATE X. Bul. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. ‘JONVISISSY LSNY SAILVYWdWOO DONIMOHS ‘SONITGSSS SNOVYVdSV ‘UODIA GNV JONVLSISSY 4O MOV] ONIMOHS ‘daziiLua4 N3dO "SONVLSISSY LSNY ONIMOHS ‘S8-ZV Xx ‘5-981 ‘OLGL ‘YSEWaLdaS NI‘OL6] JO SONINGASS 3audIGad—'§ “IF 4-981 ‘OLGL ‘YaaW3LdaS NI ‘OL6G| JO SONITGSAS ABuDIGad—'s ‘DIS "ONVLSISAY MOHS ZL ANv ‘7 ‘9 ‘Gg ‘§ SMOY “LSNY JO WOVLLY 3YSARS V YSLSV ‘6061 ‘YSdWSLdgaS NI ‘6061 4O SONITGSSS—"} “di BREEDING. 29 the flowers were hand-pollinated. The insect visitors to the asparagus flowers are largely bees of different kinds. The honey bee is most plentiful during the blooming season, and at this time of the year practically all of the pollen that comes into hives that are near aspara- gus fields is the rich, orange pollen from the staminate asparagus flowers. Apparently a large amount of nectar is also produced. This is shown particularly in flowers under bags where the bees have been kept away until the flower is old, when it is so abundant as to interfere with pollination. In addition to the honey bee many small wild bees frequent the asparagus flowers. Some of these small bees are a nuisance in the pollination work, apparently being especially attracted by the extra quantity of honey in the protected flowers. The wind seems to play little part in pollination, as the male flowers retain their load of pollen until they begin to wither unless it is removed by a bee. The pollen hangs together in masses and does not become powdery until the flower dries up. The anthers of the staminate flowers dehisce throughout the day, but by far the greater portion open in the morning hours. On a bright, sunny day they are nearly all open by the time the dew is gone. Cold, damp weather seems to prevent the anthers from open- ing, so that after a long spell of rainy weather a large number of flowers will be spoiled, as the anthers do not open well except when fresh. There is quite a range of variability in this respect and also as to the time the anthers open in the morning. Some days when the atmosphere was moist some staminate plants could not be used in pollination work until an hour or so after most of the others, and on misty or damp, cloudy days these plants would refuse to shed their pollen at all, while plants near them would yield abundant supplies. METHODS OF HAND POLLINATION. In the work of hand pollination in asparagus very little apparatus is required. The principal requirement is to prevent the random pollination of the pistillate flowers by insect visitors. So far in this work we have largely depended on paraffin paper bags. A good quality of paper known as ‘‘glassine”’ is used. This paper is nearly transparent and is tougher and wears better than any other paraffin paper obtainable at a reasonable price. During the spring of 1910 many of these bags went through a three-days’ storm of wind and rain without injury. The bags are attached and held on by short pieces of No. 18 office wire to which is attached a small eyelet string tag for records. The office wire is purchased in small rolls and cut up with a pair of shears into pieces about 4 inches long. The bags are 263 30 BREEDING ASPARAGUS FOR RUST RESISTANCE, placed over the branches of the female plant, gathered at the mouth, and firmly held by bending a piece of wire around the bag about an inch or two above the mouth. Ordinarily two branches are included in the bag in order to brace each other and prevent the wind from whipping the bags around or breaking the stems. This wire is a great time saver over twine, as it does away with tying and untying at a time when minutes are valuable. This wire is also used in tying the main stalks to stakes to keep them standing against storms. Plain copper wire of equal weight is apt to cut and wear into the stems or through the bags. In the season of 1911, cages constructed of ordinary fly-screen wire cloth were used to cover the select plants both male and female. It was discovered later in the season that a very small wild bee was squeezing in through the meshes and pollinating flowers. In the future a finer mesh copper-wire screen will be used. The season of 1911 was exceptional for days of extreme heat. Many of the branches inclosed under the glassine bags died after they had set fruit. Such berries never developed viable seed. Asparagus through- out its development is very partial to good ventilation and any pro- tective measures for pedigree work must take this into account. The female plants to be tested can be bagged about the time the first flowers are ready to open. At this time the branches are tough enough to bend readily without breaking. Flowers that have opened are picked off before the branch is bagged. The work of pollination is best done in the morning hours just after the dew is gone. The desired male plants are visited and a collection made of flowers undisturbed by bees or other insect visitors. These flowers are placed in small shell vials lined with absorbent paper and with a stopper of absorbent cotton. The vial keeps them from drying out and losing their pollen and from becoming mixed with flowers from other plants. All vials used should be properly labeled to prevent mistakes. In selecting male flowers only those are taken whose anthers have dehisced their pollen. The pollen in a freshly opened flower clings in an orange mass around the stamens at the throat of the bell-shaped flower. Flowers that have been visited by bees have lost most of this mass and the lighter color of the anther walls gives a much lighter color to the anther cluster. These flowers should be rejected, as they are liable to be mixed with foreign pollen. In pollinating, the bag is removed from the female branch. A flower from the bottle of male flowers is taken out and grasped lightly in the right hand, using the thumb and finger or a pair of forceps. With the left hand a flower on the female branch is carefully bent 263 BREEDING. oe into such a position that it can be touched with the pollen mass in the male flower. If the flowers are brought lightly together so as not to injure the stigma, the stigmatic surface will be well covered with pollen and in the course of a few days the ovary will swell into a full- sized berry. With a little practice pollination becomes a matter of routine work. The whole male flower is used in pollination, and this method has proved very satisfactory, dcing away with the use of brushes or other pollinating devices which are apt to cause mixing of pollen from different males. After all the female flowers that are open are pollinated the bag is replaced and the tag marked with iden- tifying data. One male flower will usually pollinate ten or more female fiowers, leaving enough pollen on each stigma to be plainly visible to the naked eye. CARE OF SEED. After the various pollinations are made on select plants in spring and early summer considerable time must elapse before the seed is ripe and ready for harvest. Cultivation is apt to break off branches unless great careis used. Asparagus beetles must be guarded against. The various accidents considerably reduce the percentage of seed set. The berries should not be harvested until they are ripe and soft, other- wise the seed is apt to be shriveled and of poor quality. The seed when in lots of less than a hundred berries is harvested by picking the berries from the plants in the field and placing them in small manila bags, which are labeled on the outside with sufficient data to distin- guish the different lots and stored temporarily in racks in a well- ventilated room. After the berries have begun to wither they can be stored in ventilated storage boxes without injury until such time as it is convenient to clean them. The lots of berries are crushed and washed in water, the pulp and skins washed out, and the clean seed allowed to dry thoroughly. The seed is then placed in shell vials, labeled and corked, and stored for next year’s planting. The seed of Asparagus officunalis retains its viability for several years if properly handled. METHOD OF TESTING PROGENY. The first work in testing transmission of relative rust resistance was in the summer of 1909. The previous fall samples of seed had been saved from various plants of different degrees of resistance. Twelve lots of these seeds were planted in duplicate in short rows in seed flats on July 13. When the shoots appeared, July 26, and for several suc- ceeding days, fresh uredospore material was dusted over the flats. The following table shows the relative rust resistance of the rows of these seedlings from observations made September 3, 1909. 57206°—Bul. 263—13——3 32 BREEDING ASPARAGUS FOR RUST RESISTANCE. TaBLE V.—Duplicate test of seedlings of 1909 from plants of varying rust resistance to show relative transmission of susceptibility. Rank of seedlings in resistance. Row. Source of seed. Type of plant. First lot. See Average. ot. 1 Badly rusted, near rusty bed... 7 9 8 pas Very resistant female.......... 6 5 5.5 3 Resistance g00d 5.222222 ..te 3 i 5 4 Resistance tame aa. tee 10 8 9 5 Resistance goods 2. 252 sh2-26 540 4 3 3.5 Cea ADI Fe Wises al mie aE et EE 2 4 3 Tee oe aie a GN NTs erat sts Star Daypack ive | UR 5 2 3.5 8 Ver 11 10 10.5 LE aie ees ya Bop he eR ea tea ieee RMA rs ES d : 9 11 10 LORS ae Old fieldc 7-8 2-s eeae eas TULSA Reet ea a ene ies 12 12 12 1 ie eS uate 0 CO a Aa ey SMa ee rs IR@Sistant.. 45208 cee etoeenerias 8 6 7 DREN Sites Frank Wheeler; old bed..-.-- Best resistant female........... 1 1 if An inspection of the table shows that the asparagus plants transmit resistance to their offspring in about the same relative degree that they resist the rust themselves. Plate X, figure 1, is from a photo- graph taken in September, 1909, of lot 1 of this set of duplicates, showing plainly the effect of rust on the lots. This experiment settled the question of the value of rust resistance in the plant as a mark of transmitting power. After this preliminary trial, plans were laid to test the lots of seed that were obtained from our hand pollinations in 1909. In addition to the hand-pollinated lots a sample of open-fertilized seed has usually been saved for com- parison in the progeny tests. In January, 1910, as many lots of seed as could be conveniently handled were planted in seed flats in the greenhouse at Washington. Studies of the germination and growth of these lots were made and correlations measured between various characters. In the discus- sion on the following pages these seedlings are referred to as the greenhouse seedlings of 1910 to distinguish them from other lots of asparagus plants under observation. USE OF BIOMETRY. CORRELATION STUDIES. The use of statistical methods in breeding is becoming more and more popular and in many lines is really necessary. The presenta- tion of biometrical studies is now rather common in experiment- station bulletins. If breeding is to be put on a progressive scientific basis this type of work will of necessity become more prevalent. The excessive presentation of correlation studies as such should be discouraged among practical workers. The value of any work in correlation depends on the possible use that can be made of the facts in a practical way. The great number of interrelated biologic phe- nomena that occur in any plant need to be understood before one character can be used as a basis for selection for a correlated character. 263 BREEDING. ao In the study of a plant like asparagus, where selections must be made for rust resistance and yield, two desired characters which do not show simultaneously, in order to do efficient work some other cor- related character must be substituted for yield. Again, the young seedling must be compared with the bearing plant several years later so that undesirable stock can be discarded without the neces- sity of planting large fields with plants of unknown qualities. Before any correlation studies were made all stocks were planted in perma- nent beds and grown for years without selection. Since 1910 no untested plants have been carried beyond the first season in the seed bed, all the poor stock being discarded the first year. In this way a great saving in field space is accomplished. Of course, care must be used in basing selections on one character to get plants good in another character. Where the correlation runs above 0.75 very good results are usually obtained. Correlation tables serve a good purpose in checking up the reli- ability of tests. The use of duplicate plantings or trials year by year to secure data on average performance are valuable only as they show a high correlation. Correlation tables are used in our breeding wherever possible to show the reliability of the observations made. This feature is illustrated in Table VI, in which the heights of several lots of the greenhouse seedlings on February 7, 1910, are correlated with the heights of the same lots four days later, showing that the observa- tions taken on either of the two dates were satisfactory. TaBLe VI.—Correlation between the heights of the tallest plants in 66 lots of progeny rows of greenhouse seedlings of 1910, taken four days apart, February 7 and February 11, 1910. [Heights on February 11, subject; heightson February 7, relative. Coefficient of correlation, 0.941+0.013.] 13 | 14 | 15 | 16/17] 18] 19) 20| 21 | 22 | 23) 24) 25| 26 | 27 | 28 | 29 | 30 | 31 Heights on February 7 (+-inch units). b g q Heights on g Sq February 11. = ey 3 oO = ~) &|ASs fells et ea tee les] NOOR WD ROR WR OI 100 +++4++++ +2) +3] +4) +5 34 BREEDING ASPARAGUS FOR RUST RESISTANCE, DUPLICATE TESTS. The use of duplicate plats in testing varieties or in breeding or selection is important in checking up results. Unless the correlation is high, say around 60 to 70 per cent, the test should be looked on with doubt. When these data are presented in the form of two overlaid curves, the observer is Hable to be misled, as the correlation is hard to judge; but this form of presentation is used by many writers, is easily constructed, and can be used to show the relation of more than two characters at the same time. Still, the fact remains that the measure of the correlation is indefinite. Duplicate plantings were made of 33 lots of the greenhouse seed- lings, and from them many interesting facts were developed. Table VII presents the correlation between the tallest plants in the dupli- cate rows from measurements taken February 11, 1910. The corre- lation between the average height of all the plants in the rows on the same date is shown in Table VIII, and Table EX shows the correlation between the tallest plant in the row and the average of all the plants in the row. In dealing under ordinary circumstances with progeny lots of plants varying in a normal way, these tables show whether rapid selections can be based on the best individual in each lot. It appears that there is a high probability that an experimenter is per- fectly safe in basing selections of future progeny lots on a comparison of the means or of either the high or the low extreme. TaBLe VII.—Correlation between the tallest plants in two lots of duplicate plants of progeny lots of greenhouse seedlings of 1910, February 11, 1910. [Lot 1, subject; lot 2, relative. Coefficient of correlation 0.8764 0.028.] Height of second lot (}-inch units). 2 | 8a = Height of first lot. 5, Fy es 22 | 23 | 24| 25 | 26 | 27 | 28 | 29] 30) 31 | 32 | 33 | 34) 35/ 36 | 37 | 38] 89) 40 cS As = - — i — inch units: Te 5 Spe eae eres Ug | cs || a | Se Ue Pee dea (eee (Soe te | bar al ba 1) —14 Fy oD se ae eke eee oct 95) te Heel soe) so tes 0} —13 esi teehice 0} —12 eed | ores oO} —Ill pete eves 0; —10 eee | 0) —9 ee 0 —8 Gee) at hs 3S 1 —7 Se eves meat econ aN 0; —6 ee) bere), ed bs et [er Fe 2 Sees ie Pe ea bce bee 0|} —5 Uses alee BS aes ere ote ee Beale lls ae 2} — 4 Wee hs eee S34 lsecass eos seeesele 1; —3 ae Wipe A ep fr ey He oats etalle 3) — 2 i gpa 23 Se es Aye Eee rf at MP De 5 0 Bad aed We Ufa hed Derelict aoe 3) +1 Se Pes Ie oped eta Peal Uae teaig H P ie L 5} + 2 cel eed | Shakes pees Gree Sorel el ams cell ee te 3} +3 sre | Soa) fo) Fea Cea Vege pee (ce 1 1 3} + 4 el a RS leeteleere | Gretell eres cre | oN yey exmenl letters 1} +5 eee ps eet Se |i! pe 0} +6 eae Epaleee| eos |aeeieoe es ee eee ee oj +7 eel se pets Wee es S 25/2 23) Ee ee a eee eee 1} +8 a I a Rl | ee Frequency....--..} 1} 0} 0) 0) 0) 1) 1) HW 3) 5) 4 OF 5 4) 3) tH 8) OF UD 33 Departure from mean...|—11|—10|—9 —8|—7|—6|—5| —4) —3)—2)—1)_ 0|+1)+-2)/+-3)+-4|+6/+6/+7]------ 263 BREEDING. 35 Moe VIII.—Correlation between the average heights of greenhouse seedlings of 1910 in two duplicate lots of progeny, February 11, 1910. [Second lot, subject; first lot, relative. Coefficient of correlation 0.826+0.035.] cee ee eee ee Average height of first lot (4-inch units). 3 £8 Average height of second lot. | 5, 3 q 17 | 18 | 19} 20} 21 ; 22| 23 | 24] 25 | 26 | 27 | 28 | 29} 30) 31 | 32) 33 & as 4-inch units: DOME ee Nee wae Garsowieteaeaieece ie Beets aes eas) eye all tate Poveda | ete. SA 1 —8§ Ee a Doak ee te ate A ee 3 mele Brake tte a 0 id OE Paes Na enne rare tata Mate alate atehele 7 els Se 0 —6 Be Te ee are SO reRe ta (Ire Sis els Aas Oo} —5 Fee a rey ce tale cloreyatsreneyale aa llevavara vn Seat caller le ety ARR Dy ASE Pee eco ae ee ree Pele. Be gel im ee 0 —3 Oe ee ee eae ai eaNaTe| sieiele BH (ele Alero lPeealte ae 4 —2 tm ee eee an Aaa ie ates wero sal as Sl 2heee = 6 —1 Se a eT eee ered Pere rae a eieyarelllatatmsed fave el[f=teve | aime] ee el Nees $i heel ace Fs eal 6 0 D8 oe Sie AT en ene | Lea ene Peme te ale [Pa PE ce fame are Py ee 3 +1 SL eee nn etn LY, call ira, dell rayeters (etal ener laren mers 1 picks 4 +2 i] SESE SEE a reer (P21) Fe CN OOS ma Nae eee \eee| ty Sitaveee Eee ene ee eR a rte ee yal (atetere| | ope reaf eter feral as Crete se Seca erate lecec tors allomelliocie Kae 0 +4 SB 5 MO EERE OTS PHC BBE some] ocesa ier] beter fers ee Petes Ie ae 1 a 2 +5 BY Oe ae US ie SS Ie ame ue al Biers Ieee pecan Ire Ie ee eal eae [eee atte Neretall oes = ors 1 1 +6 WYEQHENCY Ls 44-4. esas 1} OF OF OF OF OF OF Y} OF 8} 38) LY 5 6 4 2 2 38 Departure from mean.....------- —11}—10/—9|—8|—7 =6)-5)—4 —=3|—=2|—1 cee +9/4-3/+4/+5 TaBLe 1X.—Correlation between height of tallest plant and mean height of progeny rows of greenhouse seedlings of 1910, February 11, 1910. {Mean height, subject; height of tallest plant, relative. Coefficient of correlation 0.901+0.016.] 5 og Height of tallest plant in row (inches). b H 3 al og Mean height of row. Bue 1D |S 4D. SPO ppolOoposopol/oposl/oSpoljops|opojopojoapal o FS |S eS fea fee ey [Se FOS ass [Ses pe Ls fe a ay Da PR ae Hi Jacd Jad Jad Jad ] 5] oS [5S Jo [r= [es |e |= J 06 Jd Jd od [I /a/SIS} ae Inches: Al DES De erat se Pe, MSI Pate Seek 1 ea 1) —2.75 AHO Soa my See oe Das a uate 2 Seal 0} —2.50 AE Teac ohe RRS ae tenet tarde ates ria eat 0} —2.25 SO Ne ASR Pasa eee haere 1 pall 1} —2.00 EPI GaSe Bete Bcica ges Segee PEEe| ERE esd sed AE [se (ve ese lens Fees peel 1d fete Rega Ato mest Tes Wc Uses | fe am wf 0} —1.75 SF) Seip 5 Te Oe BE a eee ie dll eo Eset fee (Fe fea (onal ena ede sane le 0} —1.50 DR OR aoe ete Bemis cc tie eats ANE TY at es ves upd eas | ee Seley 1} —1.25 RODD eye acpi cece tee ie ct wh eC) we dPe LUIS ATES FO pS D(a Pelle eH Alle 3} —1.00 RDB Se eS eat Re eal anes TAS ed eee laa ena Se oe |e aL Seta 0} — .75 Hea ree Sere aS eps a Sb dl edt 24) cll elle ee CRA Ss Le 12) — .50 GeMaee eee Ne tae aa ce Aaeae eS BUN eA EB Mee PE pe al era teed 10) — .25 UCL ce i ee cr VV 10 Ul a ele) Re | ne PA Ne) AU pan aN WS I ay Waa 6 0 esa Sy Ree a ee AG Stee Peed VS VN Ep (Va be 8} + .25 Teo eee es ae ar aes weer are yma axl ped ot eee | ease Poe alba tana an a DAS ll obese 11; + .50 (A Cae act) age rr ary aie ee a | | PA sd eel 6} + .75 SNe as = te eo ee Pe 2} +1.00 SS A) sexe SEs SESS eae IER aS gOnG ae e F | PR FRG a Pe) A ST ey ly te Pn Ue) eal al fe cre | este es CORTES oe ee ta a9 Se ay al We Fe Le FR 1) BA | in| fn) pat fe TIN feel S| ESE iru bee he e8 Laat) IPeOvIeNG yen te wo Soe ocak 1} 0} O} 1} O} O} OF 1) 1) 1) 3) 4) 8) 8 5} 7] 9} 6 4} 5) O} 1) 1) «66 SIAISISISIAISISISIAISISIBIS] IRISKSISIAIS ISIS Meparturetrommenni as ee. ok ad losesfetledlailaillafaila} “} | lol "| "| Jala ]a|aifai 2 i apes Daa aaa ee USE OF CORRELATION STUDIES IN BREEDING WORK. The value of studies in correlation to the practical work of plant improvement, while not questioned by those familiar with statistical methods, has been doubted by those not in the habit of doing accurate 263 36 BREEDING ASPARAGUS FOR RUST RESISTANCE. work. One or two examples will show the possibilities of the use of correlation. The relation of the size of the asparagus stalk in the fall to the next year’s cut is interesting, as it is necessary in selecting rust- resistant plants in the fall to pick those that will give large-sized shoots. Studies of several plants in row Al presented in Table X give a fair idea of the value of large-sized fall growth in determining large-sized spring growth. In the same way the total yield should be taken into consideration. This quality is hidden at the time of selection and must be correlated with total production of stalks in the field in the fall. This relationship was worked out with the plants in row Al and the result is shown in Table XI. Certainly when the correlation is as high as 0.8 the observer should make an almost perfect selection by using the correlated character to pick the very best plants. TABLE X.—Correlation between the diameters of the largest stalks in 86 hills of row Al in the fall of 1909 and in the largest stalks cut in the spring of 1910. [Diameters of 1909, subject; diameters of 1910, relative. Coefficient of correlation 0.575+0.050.] Spring of 1910 (4-inch units). Fre- o ; _| parture Fall of 1909. quen-| *trom 2 io 4 | 5 6 7 8). 29), HON Wa) 2, mean 2-inch units: DTS hee ie ai vate aot Ae RN OM te ayer eve ese z dU Png Vy (PW feel bs ee Ite te 1 —2 Sete DIER fore crenata sre clawie nejatare Me eae AIS) Wade et Viet: Yat tanee (i [sus ea ecayNesee| yee | es NE ll 20 —1 ih RES ray ta eae eee Biel VE = Rey tl se 1 4| 3 Cael to: i Us| pear tos eteace DBE HEE 32 0 Deal Serafa lath See Oe See ee ee ee eey IY Woes ae isis aca i eat M1) De En ged | fe (An 23 +1 Gee he eee Pee Be IN Bete ee ll eral feel ae 1 1 i +2 Meee ge ors OLE eNO ete ei te TG (too J ete ce eAtate rs | bee 3 4+3 MTEQUCHG Ys eae pects tae cesta 2 Onan Ga 22 Ge Sa dh) ON a 86 Departure from mean..................-. —4 |—3 |—2 |—-1] 0 |+1 |+2 [+3 +4 |+5 [+6 | Reser TasLeE XI.—Correlation between cross section of stems in fall of 1910 and cut in spring of 1911 on 82 producing plants of row Al. [Fall stem area, subject; spring cut area, relative. Coefficient of correlation 0.811+ 0.025.] Bl aS Spring of 1911 (square inches). 5 a8 Fall of 1910. 3 Be 1} 3 | 5 | 7 | 9} 11] 13) 15}17| 19] 21] 23] 25] 27 | 29 | 31 | 33) & | S's mB }OAk 3-inch square units: LOR At seteaerieneleeee 13 ANY 3 1 RY Pe Pas get ee | eA ee 18 2 DOME cect soe ae eee chee DIP AGI Gl prec 2 | eae rl Bales 18 —1 OO Paeet eee asee ae at ae 1 35 £4 ian UT rp kel pee PS beep ge te 16 0 Oe pers = Ue ien Sea bes aed 1 (Se Paces! fertile Eee abs fol ele 14 +1 OO eres ee tee ce Ee Smee valley all ras ee aes 4 + 2 a C0 Vireo Re ee aN Oe Le a PDS ie sale sedate ere se 4 +3 POO Ra ot ye Peer A Ey ae es Pm ares} St LL be ee ae 3 + 4 L5Qjee es ees Bes eee Di etais| Seralistare 2 +5 170 eee ees ei hoes 3 ce eral ee eee Hh 2 1 + 6 TOO is eis ieee BT Vi Ec fecal | ee 2 Pa GN FENN Pes 2 ep Eee AI OT +7 PAIN Ee ne crate SRI ee Re ae Sle ony ie Ve a Pac re Aa ee Pe 0 +8 | Dhaest gS AN ea PES SUT I toa adel TN 2c en 0 +9 Devise ai aa: ies RE MR eae Ped oe 1 ec aa aes D2 2S) e Pee se eae 1; +10 PPA (Oe eager ones mre eacas ea ap MLAS eal ail Easel Rees osc Ieee [evel es oat A ce oD oe: +11 Frequency... 2:22... - 1G) Sia TS TS VOW Ol Sl 2) Ol eS Ol 0 meG en) 1| 82 Departure from mean......| —3| —2| —1) 0\+1|-+2/+3|-+4|+5|+6|+7|+8|+9|+10|+11/412/+13).... 263 4 BREEDING. 37 A most interesting interrelation comes in the size of the seedling to the weight of the seed. It was early noticed that the greenhouse lots of seedlings showed striking differences between progeny lots from different female plants. Wherever enough seed remained unplanted to give a fair average, the seed weight was determined and a comparison made with the average height of the seedlings in the progeny rows. Table XII was obtained with a coefficient of 0.780. Where future size depends on the start the young seedling gets in the bed, the tremendous importance of the use of large seed is at once apparent. To further test this correlation, 100 seeds from plant C13-5-1, open fertilized, were sown in 1910 under uniform conditions of moisture, heat, and light in a soil of uniform texture. Each seed was weighed to 0.001 gram, the germination record was made, and the height of each seedling was measured daily. No effect of size of seed on germination could be determined, but the size of the indi- vidual seed showed a very strong influence on the height and rate of erowth. (Table XIII.) Where the individual seed is taken into account the correlation is lower than where the average of several is taken, on account of the varying hereditary tendencies in different seed of the same weight. TasLe XII.—Correlation between average weight of seed and average height of green- house seedlings of 1910 for 42 progeny lots on February 11, 1910. (Height, subject; weight, relative. Coefficient of correlation 0.780+0.042.] Average weight of seed (milligrams). De- gi ght of s (milligrams) re: oer Height of seedlings. BE GS) 5 fi 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28} 29] © | srean. Inches ENR OOS COCR CORSE COR SRC r seer ete 1 ees SE oe | en eee ore ee teel ieee (serra 1 —1.00 GOO ese ae scare ners re See en aeoaee i Ll 7 eee [uate i Uh os Roepe ee ale [eSeeed fa 5 — .75 (ees HB te Soe See SoC eat hore ore cl (ene 1 1 DAE ato Sek epee earn eran a 2 — .50 (1519 sy Sy pe tema Re en Ul a eel) Le PAA NEDE UA ay bo hei oe] be steeal ie [eee sale 4 — .25 (BSF SPN nee Oot eRe SR ORE (A 3 1 1 IU see a2 aS 9 0 Fie OR peepee ees Stee Mere Comte verre oN yee Bc ese ee) 4A li) 1 Bas |e 10 + .25 Lop DB Be Aa See TOE OEE eae eS ener | Sie SEEN EN TPL cera ae LUE 2 + .50 ROU apa eee nate lcs Seneca ieee eee ee oe Bees on 7 | (iil Ol fe” Heal 5 + .75 RCD ae eee eee aiajee eine cies ae ae sane Soee Bp oein ieee sell bei case Eee ll! NAS 1 3 +1.00 1 ea cE Mi ae le ee os ee ae ee ea 1 | 1] +125 meqneney scl eta eecnee, tL ee Dia Sf Selo G10 se | ANS aH do pand tO) Wok hh ads Departure from) means... 2 ss —4 |—3 |-2 |-1]| 0 ie +2 +3 +4 |+5 +6 | urea 263 38 BREEDING ASPARAGUS FOR RUST RESISTANCE. TasLe XITI.—Correlation between height of shoot and weight of seed in 100 seedlings JSrom weighed seed of C13-5-1, open fertilized, grown under control conditions in green- house at Washington in 1910. [Height of first shoot April 9, 1910, subject; weight of seed in milligrams, relative. Coefficient of correla- tion 0.41+0.056.] Weight of seed in milligrams. De- Fre- | part- Height of shoot. | Glen aaire 12}13] 14] 15| 16 | 17 | 18 | 19 | 20 | 21| 22) 23) 24] 25}26| °%: | fom Inches: 3 Wal tel ea ecee eee Omens 1} —2.50 ve el Qa | bee an | ee 0} —2.25 ese eee 1 1 eee He2 3} —2.00 I aes es Te Sels Sea eee ie s 2} —1.75 4 1 Ye ia 1 ete te : 4) —1.50 i 50) ES WERE ee 1 re (Bee 2a ae 2} —1.25 4. Pag (Porey ee hee eee gs al Salas 5} —1.00 4, ea ear Ca [iv sel Fee a) ba il ha Seles 6| — .75 bs 2, LP aee 2 1 ee eee ie 7 — .50 Srebses Sasa se eee es eee eee 2) 2, 1 i Pace Sel es Bees. 10) — .25 OOH hs oe co oaeeeme ease 2| 1 ee 1 1 1 11] eet NW eS 1 12 0 OSTD ER ABte Ese ek scteees ick ileal 4, 3 Tees SD A ce Ul ab 17| + .25 Gee cc satcsieeniiscemecte meee nas ef ee 1 1 a ae Dele |e 8} + .50 GED 6 ee BOR ey eS 1 Ease 1 lige Tall seal 5) + 275 G50 uses acs aes se bigs See ec sal ea eval eed a ve PAV a cd | 8} +1.00 GE7Ds de SEM eae wate eit eee Pel eT ER A pe LE al Leia aera 1 Pee ae Kees 5) Weed ie 2 We ee 5) +1.25 CTR AAT Pata gece Kae pen Nc eett ie AAR RY USE Pe eR ay HS aah Ke ba i Ue Pe 1) +1.50 Oe ae Sete eae es es EN Rel Ped |Z Ses peel be al [eseyomts fust al oer Lek Cem O} +1.75 8 PR ge Ie ref LR l(a a Nene ee ea OY hese ete. 1 3} +2.00 MRMOSS teso seen ah eet tee eee Sat ANS | eel terme] ee eee es eee 1 1) +2.25 Hrequencycseeacsse sete eee 2) coll MA) lols AD Soe AOI 12 Oi eS |e) eee e200 Departure from mean.......-.-.- —7|—6|—5|— 4) —3} —2) —1] 0) +1)+2/+3]+-4|+5]+6]4+7]|-.---- Table XIV is introduced in order to show that the size of the young asparagus seedling is important in determining the future size of the plant. This table shows the correlation existing between the average heights of 85 progeny lots while in the seed flats in the green- house at an age of three weeks and the average of the same progeny lots in their permanent place in the field. The factor of crowding, which aids the stronger plants and retards the weaker ones, was eliminated by placing the plants in individual. pots February 13 and so maintaining them until they were transplanted to the field where they are just beginning to show the effects of crowding in the fall of 1911. 263 BREEDING. 39 Taste XIV.—Correlation between average height of greenhouse seedlings in progeny lots February 11, 1910 (in }-inch units), and their average height September, 1910 (in inches). [Height in September, subject; height in February, relative. Coefficient of correlation 0.552+0.048.] Average height of seedlings February 11, 1910 (}-inch | ¢, 5 =| units). g|es Height in September. g 2 ot 20 | 21| 22] 23 | 24| 25 | 26 | 27 | 28 |29}30|31/32/ 33/34) | © 8 Inches: 9 BP ees cy mills | a =O Seal eee =a ==) <1 0 ers'ai| leavers Alsoe 6 —4 bes sleeelors alone 44 —3 Dy 2 eerie a sees (ped —2 waa Morel hos lool bees) it tama h 1 Vo? Ps VS a 0 1 Yt Wr & rena We) TS Hee 8 1 ea a | Be Elie Aten ee alee a iG oh tee a) Keeeicy (epee ne U ge bara 3 +3 Beer cei eabaei 6 +4 Aah eoece| sade: cole seo Salle P| Seralloaie 3 +6 ‘ Bee fel ee | | eee ed MREQUeNnC ye ewes tees neem eee 1; 0} 1) 2) 8 2 10} 15) 17) 6 8 6 5 3) 1) 85 Departure from mean.......-....------ —s\—7|—6\—5|—4|—3| —2| —1| ol-+a/+ol+3i+4l+sl+el.. In continuing the work with the greenhouse seedlings after they were removed to the field in May, 1910, further correlations have been studied. While these progeny lots are not exactly a random sample, in many respects they answer the purpose of one, the population being distributed in monomodal and often nearly normal variation curves. In making selections among the young seedlings a general tendency among growers is to assume that height is a good index of large-sized shoots in future years in the cutting bed. - According to the tables constructed on the data of height in 1910 and stalk diameter of the greenhouse seedlings in 1911 (Table XV), there is a correlation of 0.634 +0.013. This result is supported by notes from row A1, where the total area of the cross section of the fall stems in 1910 was com- pared with the total area of the cross section of the shoots cut in the spring of 1911, as shown in Table XI (p. 36). 263 40 BREEDING ASPARAGUS FOR RUST RESISTANCE. TaBLE XV.—Correlation between height in 1910 (inches) and diameter of largest stalk in 1911 (¢-inch units) of the greenhouse seedlings of 1910. [Height in 1910, subject; diameter in 1911, relative. Coefficient of correlation 0.634+0.013.] Diameter of stalks in 1911 (#;-inch units). Height in 1910. Frequency. Departure from mean, WrequenGyececee se seeae 4| 19 | 64 {117 J171 |258 |1382 |122 | 27); 19} 9} 6} O; 1) 949 Departure from mean........ —5 nay a —2 |—1] 0 j+1 |+2 |+3 |+4:|+5 |+6 |+7 |+8 |----.- Table XVI shows a comparison of height of the greenhouse seed- lings in September, 1910, and in 1911. This table serves as another illustration of the opportunity of making selections on seedlings. Seventy-five per cent of the 1910 lot could have been discarded with- out losing any of the 10 best plants of 1911. A comparison of the correlation here shown, with the table presented by Clark?‘ in his studies of timothy in 1910, shows that the conditions at Concord were more uniform than those at Ithaca. One striking feature in connection with these studies is that the reliability of the height correlation is almost equaled by the relia- bility of height with next year’s size (Table XV). Data from mature plants in row Al show a high correlation (Table XVII) between the amount of tops on the plants in the fall year by year and also a high correlation (Table XVIII) between the cut of individual plants compared in successive years. 1 Clark, C. F. Bulletin 279, Cornell Agricultural Experiment Station. 1910. 263 i ; BREEDING. 4] TABLE XVI.—Correlation between heights of the greenhouse seedlings of 1910 in 1910 and in 1911 (inches). [Height in 1910, subject; height in 1911, relative. Coefficient of correlation 0.642+0.0126.] Height of plants in 1911 (inches). Bl nd q =o Height in 1910. Bl ao 3 | 6| 9 |12 15/18/21 24'27|30133136 39) 42 |45 48 51/54/57/60|63|66|69/72\75|78|81\84| © 58 C=] neh 7c ee a a idl TE Goel a Gi a Ee EMR aie Vb Le Re 8 Pll Fe tt A i el We basket Ne wale = 10 eee cm et ae el ra FV kp nfo gg Pa A" pe a Ee uC): dale a= 9 rs, ARE | a}a] a). -| i} a} 6] 6} 4) 3) a) 2!--) aye f- oa aa Oo a a a es ie een "taney OE BE }1..| 1/2] 1} 3} 6} 2} 6} a) 6| a) 2..|--|-- Br Dah al RG che koa OS UAE ee ~| 1] 5} 8] 6| sia} 4} 7] 5] 1) 1) 2}. apy fe a 0 he i eee a ae 2| 3] 1) 4| 6] 7| sit} 5] 5] 1) 2)_.|- ap tl (He fae ra Vel ate: Sere emer “| 4} 2} 2} elao} {12} 9] 17) 3] 3] 3] 3) 2 af--fo-)--fe-fe-[cfe-f2-] 79) — 4 iS ane 3 as _.| 1.-| alto st 7aa} 9}-51 6) 2t 4f..| foc) foc Pec] ] 67) — 3 Tete Deine Oe -l al at. -| zal 5] 17ja0l 8} af 7ic-}o.[2-[o-]--[e ef) 73} — 2 TIS a OES Be 1] 3] 4] 6} 5/12) 15) 9] 6) 9.11] 2) 2)._]..)..].).-).-].-]--] 85] — 1 (Se Dee Be eae 14) 1) 2} zaal olnataa! al al af. ( [I] 79) 0 CSAs EAS aR Be i| 1| 21 3] 3} 8} 9ltof 813.10) 2) 1) 2).-f--|--]--]--|--L 2] 73) 41 | 1} 2} 2} 3] 9f zizol 8] 9) 5]. fo 2]2-]2-]22]--]--|2-] 56) + 2 I 1| 3| 3] 2] 10] 9{12| 8| 6} 3] 3i..|..|.-|.-|--[--|--]--] 60] +3 1] | 4} 5] a) 2} 5.15] 5] 6] a) aj--|--|2-f feof} 46] + 4 1] 2|..| 3] 2| 4 7| 5) 4} 3] al--]a)--|--[--|--[| 84) 45 “| a} 2l--] 3} 5} 3l 5] 5] 5] 6} al..|-|--|--|--[--] 36] 4+ 6 Vo../ a) 2l.-| 2} 5] a af a} a} ale |ocfocccp} 19} + 7 2} 1) 2} 4) 4} 2] 21 3] 1) a}.-[--|--]--Ja|-.| 23) + 8 Maer) 1| 2} 1)..| 2] 3] 1] 2)--|--|--|--[--|--} 21] +.9 La BU sf fe PF Pe J ae 06) eu By WT 5 a br f(t | SL i i Fe ae SO gS (SBE far al LS alte nies pelos) Ll SF <3 é 71 es pe Pa 8 eee y r i Sl el Sales 0} +15 SA Ball tea ols Welleadeoag : besa eae 1) +17 Frequency....... 1) 0! 0} 5| 1| 7} 9/15/35/55|69|84/91/126|92/93/92/$3/42/28]121 6| 1] 0] o| 1] 0] 1) 949 Departure from mean../2 23/2 |S aes g\e\e |" SOP |S 1? 1D 1S IOS Ea |S [83 [60 |e |S HEE PUT PA Peay Ty aa a a TasLe XVII.—Correlation between area of cross section of fall stems of row Al in 1910 and wm 1911. [Stems in 1910, subject; stems in 1911, relative. Coefficient of correlation, 0.859+-0.018.] Area ofross section of stems in fall of 1911 (4-inch square units). I tH “— : is oq Stems in fall of 1910. a as SneRie fo) 3 slelsisis| & |S AA] A | ow | Fy a) Se ae ee ets Be 18} — 2 ae | ive sere fave =e 1s) —1 Be es ise eae ee 16 0 Fe ey See (ee Be 144 +1 Doe 454 |G ae See ees 44 +2 ABA tod bean Boos ae 44 +3 Saale saleseel net 55 3) +4 eae) aecllenes Seen ats 2} + 5 Bs See) eee eae 1 1) +6 Bere Se) aA, Petes Pe Oo; +7 Brag te) On baa BS Oo} + 8 AGS Rea | Week ao 0} +9 Fe | ae ies lee 1 1) +10 3: rae bee 1) +11 Hrequencyzs-: 22-22) 10 915], LO LO a Sy 9) 7) Ay Zi, 2), Ole ‘OV 0 1 2 82 Departure from mean..... —4| —3] —2) —1) 0/+1)+2)+3/4+-4 +5/+6/+7/+8)+-9)+10)+11 +12)... 263 49 BREEDING ASPARAGUS FOR RUST RESISTANCE. TasBLe X VIII.—Correlation between the yield in 1910 and in 1911 from the plants in row A1, given in the sum of the squared diameters of the shoots from each hill. [Cut of 1911, subject; cut of 1910, relative. Coefficient of correlation, 0.797+0.027.] Cut of 1910 (square inches). 8 & be () Cut of 1911. 3 | BS nc o ~~ olxA 3 A re N on =H Le} co ~ ioe) for) mm ° toa gS 28 | S28) Sie he eau o ea aan olnx|nl[miaw[omolol|jrjololrA ay A Square inches: (Uae eS ene Dees acess Seema aur 1 cfs) (estar) kennel ape FPR IS AR PRT rea Ree ee ee 16 6 DiGOA Ge 25 epee ias She 2 Gea ee os 7 6 ED HOTT on Ae SA MI re I br es baa 14 4 AGOVG 28 ee ae cette cE ecient eRe eae ae pe Tee IRS a ee se apes IN Pe 13} —2 (Oris ee Se eee Bate ae aaa mamiatsetacne Beil Teeara| sell naa | Sea Seo MET Nhs See teste pee 13 0 Si COMO ec. seysep ey. dere Dare chee renee Sree]! Tea RV Mis 5 eens Pose engi) Peta (EY 6 + 2 ICG 0 lb? Fea a Ar a TRS eM A Mts ee IS Cte eal bee 8 3 1| 4 AU Ages) (Beek Ns eS ba 9 + 4 M2 OWS Sek ioe elses Bo coreete icicle arta |e eel erste stetere Array pti! WIR 741] ieee Piss) [Sete ees (oer 3 + 6 WATOWMGM eR aaa ete sete tei sierote aetna er teeta ict Nel terere [eine 1 Lee eee ie at eats 2| +8 MG GO WB eee chic L htok loatenn c drthe erat steal ate Sa svete fal Senes opener Ng tt | US CEE So ea ae TEP eeeld ee eae 0 +10 AS COO ets eo a ey 2 eas Bs Pees (oer Puen ease PAB eee [eer 1 Fons Ha 3 +12 ANT; 0 97g aon Pagan PEED ae RNa tes ES Pr Wl nN ES aj 24 Werner] ghey a esgic Paras val Pages tet oP hs 1 1 +14 D2 TO 2b actos ee Saran selene seats atts Sees) Bc ges) Ie STA eee et ei ae Parsi Te a Ae 1 +16 MTeq(UenG yas: sec Ce ae Be oeee eaee oets Peete ae AH ere cio retest ua Oy MeL IN Oty at 81 Departureifromi means. ja -e se. s\-seeel —2|-1] 0 |+1 |+2 |+3 |+4 |+5 |+6 |47 |+8 |..--..- Table XIX shows how close a selection can be made for stalk diameter in 2-year-old plants by saving only the tall plants. This method, of course, is much quicker than to measure the diameter of the shoots of every plant in the bed. TaBLE XIX.—Correlation between height (inches) and diameter of largest stalks (Js-inch units) in 1911 of greenhouse seedlings of 1910. [Heights, subject; diameter, relative. Coefficient of correlation, 0.7920. 008.] Diameter in 1911 (;,-inch units). De- Fre- | par- Height in 1911. s WRREGT ToRSIEH GH Ge |e eta ae cy rom 1 PRA Mehul lve So aon NeW a VP Vta ests} ty AON ITED MO). FN Hl besa Lay yea et mean Inches Bee aha eas ete Nea fole eyatore 0 [eal oe ale Pan Aen pel i Lo a We aS ts 1 —39 (CE SRE eE SABE UABACEoae nse Per a(S o4o|o seq Soae Eene moe S| Bosal esa S Selec alla salty see Sh. 0} —36 (ei See Set re Sea dS ae We eo el eee sie or aS ol oer rer llseea| pou otal peach ao 0} —33 Deke taal ee eee Ny Poe Aa ee exes ees aes Skea kee eal Estes ERI Kase Pa | |e lb i LSet 5} —30 ML ate a iop ia Ni rca ae atc eseg eee ae uae) Wee Fed VQ Dis Pa ol a a bi 1| —27 Ques Aas Wee se ee ae ee ees 7a MS Sy epee ne Tee i Vp af S| le a en 7| —24 DAN Save tle Candle ey eee seal ee Fa ea en ae na |e SP Ot ee sel ee 9} —21 Day rete UCR” So Deer ebi ey kaya ee Beh Op SA eee RIE ES eae ee reese eet 15} —18 DiTae ye Sete a ea aicres Sr pare reve eel | arto Aa bs Ble al ars yo ay Fie Fy meee PO 85} —15 EDs a eat ete a isle seer| reed pa TTS Si LAT (aa teat er ah eye ase Caen) Lene Peete | tiles sell Side 55 | —12 DOR Rinse Wane Se sea aeie Sele siete Oey QU QO) ee Sais See eee ee Sees eee [ert ete 69] —9 See eA SEEM Eo aaa earner Bet D5 EDOM ALO ell eer) | eared eles) yee | et el Fe | a 84] — 6 BOT ey Oe mes Saucer Banca a AW AGATE QOM SUNG ii lee gtsctec eee evr | aha) ete Maes 91} —3 AD SNES a ale ape ate tele cays ol| mei tall oes ees eke ETN BESTA Zl seed po tga (PIT ep Peel be |S 126 0 Cs as eek a PB Seaman et (| aaa ee DV LGM rah Ale aU sia lel eae nls Mocerel le ere hea 92} +3 AR sO eee oe eS Pa eee tee elaiavel erase | oeelete De AT Oe BaZa | 1 AU) petty 93 + 6 Grp Fie 2y APA an gig ast en Me | Sear a eae DPA OF hs OS nie aellee isle | teal | ees et ol ices 92) +9 Gif Ty Te Nel aici ee eas et dna arial Pleat Faas | Bue a (Maan a Pies MES 724 oP | Ve Ui Neen (ag) beeen ae = 83 | +12 LY MOSS ERE Ree Reta [-oat a [Wr emer ee aac Tale) alan Me Oulicolat 0: |Leerell accel tees 42, +15 GOS See eee las She a ere ete ete all en Waaten ve el atin o lee dM ase Sol oe) NS Ye ator a Ue se 1 28 +18 GS 3858 ok eS eee ele eae se a ees pa a ea Shelia PAA Paar pac 1 12| +21 LaLa tate se Cael pha ei ea seas egy [eh HI Nee Sra 273 4) LM ee Ret Pa i 6 +24 Oe ree TRE ESAS DN Cea eae LOU Nae hs |e Gand een | eae ae 1 is a ai| oie yas eet] Sees eee 1] +27 DSRS arpa ES See er me eine Pail [Menta kee are Mere aren fe 8 | lf a cap mea pees fay fio Nee es 0} +30 SPS eRe ERT Ay eset eg eserk S| GH eg Lope Pee acl) Lt RA RR ay eae te [Es eg = 0}; +33 1b Sen SPP Se nen Pe ey A to al KI Ue Hite | ee ( IN gee Bae 1] +36 Bue ie See Sy Aya es eT a Kye NLT ap al ea | a a 0} +39 FY NAA Sea SSS eA A ye DL ace ca (esc Ne bee Ua af 1 |e 1| +42 Brequency 20-3227 she 4 | 19 | 64 /117 171 |258 /1382 122 | 27}19} 9) 6] O} 1] 949 Departure from mean....-.--- —5 |—4 |—3 |—2 |-1] 0 {+1 |+2 |+3 |+4 |+5 |+6 |+7 |-+8 |-.---- 3 263 ——— BREEDING. 43 All these tables go to show that in asparagus we are dealing with a stable plant with a permanent individuality; that an individual char- acteristic observed one year will persist in nearly unmodified form. in future years. Without a study of this kind any breeding work would remain an uncertain proposition for several generations. VIGOR OF SEEDLINGS OF MALE A7-83. The several lots of hand-pollinated seed with the check lots of open- fertilized seed which were sown in the greenhouses at Washington in AVERAGE HIE/GHT /N INCHES AWERAGE HEIGHT (IN INCHES FEB. //~-13/0 4EB. 11 13/0. : ‘7 "9 eo @ a 7. OD FRAT ae ae ae ee ee aS Ss Ses ee 8h CHE QTL LL DOL ER HG paxd ES 4 one = SS aa es 6.82 85 \744 Fic. 2.—Diagram showing the average height of 87 progeny rows of seedlings of 1910 in greenhouse. The measurements were made February 11, 1910, for comparison of open-fertilized and hand-pollinated lots of seed. PRR DWVGRGRER GRLRI BY avV January, 1910, were planted to study the effect of the different par- ents on vigor of the young seedlings. These lots of seedlings varied markedly in averagesize, and it was easily seen that the open-fertilized lots of seed as a rule were shorter than the hand-pollinated lot from the same female plant. The accompanying diagram (fig. 2) shows the average heights on February 11 of the entire series of seedlings arranged in classes showing the different lots of hand- pollinated seed with the sample check from the same female. The check is shown in black with the different pedigreed lots following in outline. A study of the diagram shows that wherever male A7-83 263 44 BREEDING ASPARAGUS FOR RUST RESISTANCE. was used an added vigor is shown in height over the check, which represents an average of the selected males. Of course, this check lot is influenced by the proximity of good or bad male plants, but usually several males would be about equidistant from any select female. Several other males show an added vigor, but the lack of rust resistance shown in these lots when exposed to rust in the fall of 1910 removes them from consideration. This difference of vigor is still maintained in the seedlings of 1910 after growing two years in the field. Of course, rust has entered into the effect now, but it cer- tainly has not been the whole cause of the marked increase in the progeny of male A7-83. The size of seed being so important a factor in seedling size, it was thought best to contimue this study in 1911 on lots of seed of the same Wy —A7-/9| ep AS --- A7-83 a cn m3 ee (a) no = - Ag) is ‘oY —— ox =a 13 TR IS. TE. IE | AD 1 AO a Oheigs ie 23 eee eee IN CENTWIETERS Fig. 3.—Diagram showing the height of 50 seedlings each from A7-25 pollinated with A7-19 (male) and A7-83 (male), seed weighing between 0.021 and 0.024 gram. FREQUENCY average size. Female plant A7-25 was pollinated with both male A7-83 and male A7-19 in the summer of 1910 and carefully weighed seeds of the two lots were planted to show the effect both of seed size and of vigor from the male. The effect of these two factors on the seedlings when 10 days old is shown in Table XX. ‘To show the effect of A7-83 on seedling vigor, 50 seedlings from each lot repre- senting the different males were selected from seed weighing as near as possible the same; in each case the weights ranged between 21 and 24 milligrams. In the diagram shown as figure 3 a comparison is made between the heights 10 days after germination of lots of seedlings from A7-25 pollinated with these two males. The result shows that the added vigor of the lot from A7-83 is due to something besides large seed. 263 BREEDING. 45 TaBLeE XX.—Comparison of weight of seed and height of seedlings at 10 days of age from two lots of 1910 seed from A?-25 female, the two lots having different male parents, A7-19 and A7-83. Height of seedlings (centimeters). OU anee Weight of seed. 12 |} 13) 14) 15)16| 17]18]19 | 20} 21 | 22 | 23 | A7-19 | A7-83 Milligrams: 7 7 7 7 TSN inate Tees TOAD IDO oO le etal bekiye am ee tay gc eseennetnl- sare va) ms RUST RESISTANCE. To any one familiar with rusty asparagus fields the injury caused by rust is apparent, yet the actual damage is hard to estimate on account of the different seasons affecting the cut of the crop. Table XXI shows the relation between the percentage of stem cross section of the crop of 1911 to that of 1909 and the rust resist- ance of 1910. Several plants growing in 1909 rusted so badly that they died before 1911, and are therefore excluded from the table. It is realized that the increase in size of asparagus hills is influenced by many things other than rust, so that the actual effect of rust is much higher than the coefficient given shows. 263 46 BREEDING ASPARAGUS FOR RUST RESISTANCE. TaBLe XXI.—Correlation between the degree of rust resistance in 1910 and the percentage of the stem cross section of 1911 to that of 1909 in row Al. Rust resistance, subject ; percentage of stem cross section, relative. Coefficient of correlation 0.393+0.065.] Percentage of stem cross section of 1911 to that of 1909. De- Rust resistance, | | Pre | 2 in 1910. aueney> fue 20 | 60 | 100} 140} 180} 220 | 260} 300 | 340 | 380 | 420 | 460 | 500 | 540 eal Grade eo aesspeee dt eee Gl 2A Wass e|Sooslee despecces | scase|eseeetee see ects sates 11 —+t Wee iis see 1 PAN eae 4 esc ee el Pee Uy eee oodo octirc oeeorl moore Ecos eases 9 —3 PRR ae eee Sy Het Aa ee 2) ase ee AS et ace Pe el Ie, oh 8 —2 CEE Hae ea 1 Ieee ion? lak aba ci yr 1 (eee ae ee recta ate eal 5) | agate 10 —1 Ae aN Io | eee | rae Ue iics Salle eae eee a eeebc bose mecca Eicooe|ssse 6 0 Deceased Sihae hese re | ryt eka |e ee 1 Aol Pape mane 1 10 41 Goi eaeee eee 1 All RSS Ease i Ae inal EOS eo ei Ft Se | eae lame 10 +2 (earec Gatar en |saece ess, - i eee] el ee ees once ere ore Weascas| Basse 1 6 +3 Bea eae =| Perea (ee Soe ooo Rees ese 3 Wes aoa aed Same olyoe oe ee tee ta) +4 Frequency . 3) 15; 10) 16) 147 6 8 1 0 2 1 0 0 2 (eh eet Departure from q MEAN so. cee —160}—120/—80/—40} —0/+-40}-+-80)-+-120]+-160)/+-200]-+-240]+-280/+320/+360]....-.-.]--.---- In 1910 a study was made of the rust resistance of the seedlings started in the greenhouse at Washington and later transferred to a permanent place in the field at Concord. The rust attacked the field in August, so that in the latter part of September some of the nonresistant plants were dead. The seedlings of the several lots were then judged as individuals, and Table XXII shows how they ranked in rust resistance. Lots 1, 4, 8, 11, etc., are from open-fertil- ized seed from the female plants used, while lots 2, 3, 5, 6, ete., are from seed hand pollinated from male plants mentioned in the second column of the table. A study of the table shows A7-83 to be pos- sessed of great power to transmit rust resistance. The results shown in this table are those on which our breeding work is now based. A7-35 is the only other male showing desirable resistance. This male is being tested further and may be selected as a breeding plant. But there is now no question as to the desirability of A7- 83° (PL Xx) iss and:3; "and: PED): Taste XXII.—Rust resistance of individual greenhouse seedlings of 1910 in progeny lots in the field, September, 1910. Parent plants. Individual rust resistance of seedlings (grades). Num INO 5 ss || DEDIG | Mecue 9 Sach Qld. (Bee lays des Wesel Boy ete TS: LD is pens JAS EG thal Engen en ss Ou etes 1). LSA Sales a Teo) SSI sl ae ae 9} 6.25 ATS ee eee | el ste tas el es Bese PAN Vane Fee fea Nyt at WP at 14) 8.50 BiZsoo05. eee 3}- 2 1 4 2)-=| > 4] 2psieci Sener 15} 5.47 NSA=3 Se aa | sesicnsene ae ne ceisecieees 4). 2 2h 212. Sales 3A BA 10) 5.45 AVA1G): S Aelieyes Beret 1 A al (Se es) ses) Soc 2 4 Ay 2] Sle - Salad 10} 5.50 0 no Sees id St aloe eallecs ee Horwi=) == 1 Sat ol SU 2 nee 9} 7.39 AV-S5 die asco ness 4 Sy ae) Be es IS so PANE UVic: 5 een) Wa I Fey Wa se 10} 5.30 NA DA oe o. Soe San Gee atesisiece ro] el SS) BE ost So] re De 2) Aes | ee ee ealee 10| 5.00 AR 73 i) pe se re 9S A Nee OU x6] lh Tipe a ars Poy ee WES 9 ies ed ea ef a 1). 10) 6.35 NG fond Rs tae a ae OO el Se NlS - lee 2) 2) 1) 2] 4)..) 4)..]..)- 15| 6.67 NAR OO Saal pees as 11 1 8) Oh 2 ee aL EE Se Re ree: YAY a 3 ay ee ae pee 6) Ve) (eR Fe re ad el Sy Pe Te le ai] ee eet at oy zt ok 9} 8.19 DUS oases eee 13 5 ls dl a \alceyepltal ald ste 10! 6.25 Bul. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE Xl. PLANT “WASHINGTON,” A7-83, SHOWING THE GENERAL TYPE OF THE BEST BREED- ING MALE USED IN THE RUST-RESISTANT BREEDING WORK. (Photograph taken June, 1910.) Bul. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XIl PLANT ‘‘ MARTHA,” B32-39, SHOWING THE GENERAL TYPE OF THE BEST BREEDING FEMALE USED IN THE RUST-RESISTANT BREEDING WORK. (Photograph taken September, 1909. ) BREEDING. 47 TABLE X XII.—Rust resistance of individual greenhouse seedlings of 1910 in progeny lots in the field, September, 1910—Continued. Parent plants. Individual rust resistance of seedlings (grades). Num ber of |Mean. 2 lat AG. b2 be Lo. [ao Dlants- el a Fd i 10| 5.70 ali Neal ea ae Asai 4, Wigbeye Be 15| 6.07 Ae ime ee pet a1 22 elf Sea CHS ee 10} 2.70 TU Ral FETA rt || FR TV ES 8| 5.19 TU SO S24 EPS se aT EF ie 7| 5.29 5 fue ea iif) GA ee al Sat a PS ike 18] 5.58 ri], au ed Fs ORT wT i ee 10) 5.55 fea ie | eee Ee ees eb Fa 10} 2.00 shee ees ee LCS elas aa Toe eee. Beate 10| 6.10 pie i ert FESR I a) eWay eV i eg 19} 6.82 SE oeetees Cie ta 4 a Seale Tl eie Bs 15| 6.23 eg PSE eat et Rc] [RE SSE | NL GG 8] 9.50 PAY RANT Reese SME a AS Nd als 9| 6.39 A (as S| Bie Loa [a3] eehe| Selests [acidic 10} 5.40 ea NT | vase fa | a VE 9| 5.39 pe asi Na Ro tr WW 10| 4.90 lial at ae a | 502) al Poa rl) Sri era 10| 5.95 US YEA RS eS ill Siaala oe a saleals 11} 5.68 SPSS RA role oles le a abana ia 1 10| 4.20 EWA tee a haan RT Be ee | |e 10} 3.60 eS NR || i a PUP ea ff 10) 4.85 TS TA ee Toll] ty Sibel ascents RE 9| 5.78 Ba Ee ee Be 1) 3} 1] 4} 1). 10) 7.55 Sa (0 a al Peale antl Gio 9} 8.05 x S 1 P|) a sr 2 et ie 10} 4.15 | elf 28s el SIE OTE aie mo Mesto 10) 5.25 OS eo 54 PRS LS Foe) a 1 ee |B 10| 4.65 BeNOR SPOT Sa a 11) SE 9] 5.50 CSRS SS) a ia Ea ( 9| 6.06 DAW yo ee rl a (a S 10} 4.10 SAN HL IE Fo Pi PE TR 10} 4.10 ASS FS SIS. | Si Dace lidscle te 14] 5.39 Fast rl] 8 ST SS PS pa PTV glace PEO a SIE Se otal te 15} 6.00 DOOM Siealeae|e sles oe (ee eae 10] 4.05 3 FAG 2) TTR] PU 10| 3.70 1] 2| 3) 1] 2 eta fa er (a 2 14, 5.07 De Pola TES eer ee 10| 3.70 a a pa | pal SSA RS a 10| 5.45 eae ZT] rt aS ST 1 Pa ih a 11] 6.77 PA MRA BY Na a ea We PES Dl a Te 8| 5.44 Re ea ee YS Ss ee eae ysis 10} 6.00 Sire) EU ia i Na ec Wie 10| 8.05 aS tA eR il a eat an 10) 5.85 OAL Neat Weal bef) Mia I EN 9] 5.28 SO 8 ORS al HRS St 1} 1] 3) 213 10} 8.25 ais St et OPiS 2) Mar MPR He ha V0 11} 5.96 ASE OHS Tha (oa By Sa eT 10| 3.35 RONAN SIS Oia bts 10| 5.45 PAA) a VANE PS Ee (a Vc 10| 4.20 ALE A lin ae Te 10} 4.95 1 atl ie Ee TI GI es | ee (Se 10] 5.15 (CESS SN 66 Ups Sie) Na al meee So [eipics| os 9| 4.33 SE AA st Gers irene te ape tncr ocean LG 67]. LURSCU all Gil eG) al ie call Sl 10) 4.35 Vea he a ESE 68). mL SUNN Fe 7a he eee oS 10} 3.90 OPES AID Le Ta Cee OPN RTE Ha Trt ERE ae Vag FO Bo Fa 10) 2.75 (iB S seen un 70|..|- LUPE AG 8) NY a Fn A) a es [Py 1 3577 (Gif REPS ee eT 71). TTI) StI] oie 4 Md ae a Pe 10| 3.45 VV are i a RE iT a (VP is [ey 10| 2.00 OURS i fe OI si a Ri Pee ne Tale: 1 bal Feet Pe al LS I a 1 Lg Ee bes 10] 2.75 PATE GbR ele. oe 8 7Al_. STH 5 fe te es) V1 aa cay a ee 9| 4.33 (CFSE Se ene 7528 Hee Heels AT Salp Die s| col alee A oe 10) 3.55 COTES ER TSE RR a ee 76)... TUN eos] PS Sh Si 24) ee PP FP 9) 4.94 ERS Nie ry 25 Tides | ea Se ete eG at) Rf elt a -| 2) 4) 2} 4 10) 7.35 Weiter ste tee 73\ 2. vil EAT Ea 2S ea Pa VRE he 10} 6.05 (OI SSAA USS 5 Se RIOT tye ERE bi 79). - 1 Pas Baa ETI SS VRE ie) i ie fr a 9| 5.33 NG ES iy ee yD a Near 80]. . DRO Ash eS | Ol ale eS al Ole f 20) 5.43 O1Z25233 2a ea 81]... Tl ie SAP ZAN S| TIL asta ee fe MS 14} 3.86 Werle oe ee 82]. TOS St Gia! 11 19} 4.58 (CHESS RE UM Pa aS aime ORAS EBS iT Me SHiesr1) 731] a pa a oe 10} 3.30 INTO pores ae SERA a a rs era (61a 1 aa 15) 5.27 A7-8hie 2s eee CS AAU SIRE TRS 2) (a ES aCe Hea he a 19} 4.21 (CIDTE 3) eee ne ies Ea aps 86] 1].. 5/1] Pes] Mie} Sar 9 Ps (9 pa 2 10} 3.90 SA 7-85 322 eee 87 ie ek: ee Petilensl eres ears Cos 3 10} 5.50 CHES y Seen ne 89}. .|.- THT 55} 1) ee (I Ba cae ite 10} 3.25 POta Roc. coe eealsoee 2/13) 1/33 eee eee ne 1 Ob Tear 57206°—Bul. 263—13——4 48 BREEDING ASPARAGUS FOR RUST RESISTANCE. Table XXIII shows the height of these greenhouse seedlings at the end of the season’s growth in 1910. Again A7-83 is found standing out above the other males in the transmission of vigor. As men- tioned on page 44, in respect to the vigor of seedlings of some of the males while in the greenhouse, some good lots are found, but they are poor in rust resistance, and the male parents have been discarded. TaBLeE XXIII.—Height of individual greenhouse seedlings of 1910, in progeny lots in the field, September, 1910. % q Parent plants. Height in inches. Bl ous a qo ° a2) S| 4 a| 3 | 2 xd 7| 8] 9 |10/11/12)13 1415 1617/18 19 20212213324 5262728) 20 so 3|30] 8 2 INGEN A as BSI lhe AICS ota SYR Sl es EIEN fies | el ete aoe eal el OHIO) A7-83 2) OR i JR ed Veal West et Le es eh a 14| 16.79 A7-85 SURE I Pru Pe Ee Sa 9b ES VE oo ale 15] 16.00 INGE BIC Bay fh Se BNA ee | Lia 10] 13.20 A7-19 Pa PANNA A Pe A SUID | WWE Aft ed BEEN be 10| 12.50 AT7-83 | en ag ce ge Ve cha ES 9} 14.89 | AT7-85 Bet ad) | || a | el 10] 12.10 INAS aio ENS Sete hea pce te | free | are | fi 10| 12.10 . A4-23 SE a st Ie a | ee 10] 15.10 A7-19 ae LS Seer eI SH) Tl Gay BOAR a eal 15] 16.00 UNA 62 Bene SON ry HE) rae Ue ey aU shy dh aU PU ee 11) 15.64 A7-83 a eR Pa aT 0 gM | A LS a 9] 18. 44 A7-85 GURU ESET OS EG eri PTT ZU Se Rea THR tes a eS a) Tce Ty PAG = 25 eee SS CS EE SHIA PUT ry ETH) Ia ee 10) 14. 40 AT7-19 Ses BEN ar Pr AEA Pe Ae ae TS OIE IN 15| 12.07 B24-13 v2 esto PD TE a TP I 10} 9.20 ING=1O eretetite ee Bs fase THEN TP Pe ESB e 8] 12.25 A7-7 pas | EM | pest] en eal Dat et 5 pad Es eel ( 7| 10. 57 . A7-19) EME) Ge Cl Petal et a an FP Se eel Gaels 18} 8.89 B12 1 SA ree fever STS HB eK | Fe WE a 10} 10.00 B24-13 BoD Sse EN cel fl Gg 3 ea We i 10} 8.10 BS923g) 2-5 oem De) SU Vr a Ta Cd Ue ec ein .|..]..] 10] 15.10 A7-19 BROS Rs WA i a yO Z .| 19] 15.21 A7-19 A TN ices HVS crea (Na gil it a Fa FR .| 15] 12.80 AT-83 Hee et gl sal etl ieee f el GG Bal ty 8} 11.63 W- 2 yr SES SEI Th SA au iP SSA ey Pe a 9] 14.22 BOs) EP a 11) i TF | 10] 12.00 B98-32 Ht SG TEE Pi 54 Gea ETE RHE SEE 9} 9.17 ' BRAA 14 sea eee A et A ee | oe a es 2 10] 16.70 B12- Si Sy PU iad ANd ST Oe aN By TE M 10}.14. 90 f B88-63 UOT ES MATH feo Peal eee Med oT US 1 11} 18.09 , B90-10 TE NN ES Tes UP | PH US esa fe 10] 15.00 B114-31 SAAD 0 S| | it] | aml Ps a st 1 10) 14.80 BS4-44)2 Ee ery Fy TY PP deca Pea lye aE ba 10) 18.20 A7-19 Hos (2 rt] 2k en aT We aa 9] 19. 67 AT7-19 GE) ep PH ey TES Ra acres ah payee 10| 20.30 AT7-83 [PH eS ay et A sr gO aT eh ete ee 1 9] 20. 44 B98-32 sl es 89 |i SS ice ea 10| 14.70 B98-44 iste ese ef i ee 10) 17.40 C7-5-12 SASH Ep Aiea OHE SH ears el al ea ee S/S S| 2 8 10| 15. 60 C13-5-33 irda eS alas oR cI THe eae SE z ..| 9] 15.33 Vee) DoE NE IPA SAP Py ST ONT a} ANP Sa Oar TL TET ..| 9] 16.78 S447 |gaee tans 1S ee a a ee 7m a sh eo 1 10| 15.70 Cy eA Fes ol Oo) Pr a PLS I STR Ody TSANG A eS ae 10| 14. 40 Weal SULA Ae Meo ane Polen) OSA TMi TE SE Ae ls y 14} 16.29 R46 Olean eae EPS GA a eee De) eT YL Ue ars 8] 11.63 AT7-83 Ne Ns | S| |e | mR eT | |e 15] 12.07 B88-70 FY Nf ia pa I ae fea Sea 10} 9.40 Tey Fe el | aT OH ea 10] 12. 60 A7-19|50]..|..|..|--] 1] 1] 2) 3] 2} 2}..]..| 2) 1}../- Sit a Va F 14] 11.07 BROS ARI Hl | ea ea ese eek eae Na aD Ss SN 10} 15.00 BUA 31521 eT Oa al al teh ST aT |e i _.| 10] 13.50 13h hi bail Poe en FSS |P (25 a ea) 3] Pate Balle Palle --| 11) 12.36 S10 SP Ee Wop (eel el ae aay ee fn mA GPa vil tl) Bea | 8) z .|.-| 8] 11.25 Bis2-26\eso eee FPR (FT Pe be nea CSU | 2 a a Oe 6200) UN PSC= NV le eg VG ll VS WT Kaa PE as NL SNE SS I aE ale) palate BSSe63 57 ME a aS aOR) No) EO A Se STS ee SW LOL ves) ase Satie eis i BREEDING. 49 TaBLE XXIII.—Height of individual greenhouse seedlings of 1910, in progeny lots in the field, September, 1910—Continued. a 8 Parent plauts. Height in inches. a 4 S S| Be im! oO \A 8 aa 3 | El 8 2 XS |813) 4) 5/6] 7| 8] 9 |10)11]12)13)14)15)16)17}18) 19) 20)21)22)23)24)25 26/27/28) 29/30/31 32).5 S Bis6= 4). eeesee Fees dl fet Kat is Cag Ap REST ES Sa PLD ae Pe be (ge ae Pose Ce W]e eS Pr) PNT 5G elon eee (Gee ela ee SN ee ea A TSS eM ey See eT TOW TOL 10 — 1/60)..) 1 2) a fe ag Sy HTS VY (2 aU We WF --|--| 12) 12.36 TA 2) SUI GI al 98 a) Va as UM eb DSR TO T2210. Bil Z6=24) eons Cad st I eye UP) a WS ea MP ba --|--| 10) 14.40 COR ELF tat) PE Me OF at) 1S) 0 at OP ese ne Oe oo /s=eORT52380 B140-25). . 2.2. 64 BP eet aed et nas oa ceed ee | | 1| 2 .-|--| 10} 18.90 WZ-D AZ GSS elle} ects seer sel hss) -pee nelebleele | eloc 1} 1 1 1 -.| 1} 10] 21.80 COTS EGS (5a PO ye) Bee ee | PR) ba a PV Va fee VV Selb 9| 14.56 B144-16|......-.. LRA Posed ey ees Rey PS Fs Fae bi BE eee Pt Pave 1 SASS LOG: 30 HN UG CaS) a ae) ee nH ny VR) a 7-4 WH Up | faba a a alee] 4220 C7-5-12)69}. AN) rH eH FT) Va Pea ar ea Wi Sele tel O al 2050 C13-5-33]70) . pt pea pke4 P| 20 fs yf He sale) oh) LES C17-1-23)71). . 20) i Wh 5 eg pee ee) be eda UB Fe --|--) 10) 10.20 W- 272 EPR Ms i a ..|-.| 10} 10.00 C6-3-14|......... (poet ey CAR AT MEAT UP lM Pa Sele 10, 10. 20 ING EVI Med oe PE ff ee ol eel el Pe alts 9) 9.33 C7-5-12)75}. .|. |. TA ee atest 4 Vee Ne 8 Ye LN Ue 8 Hale 10) 14.70 C6-3-31)......... @o|Se|2=1)- we | ES ep ee Pe eH Sale 9) 15.56 A7-83]77}. .|. -|- He lied tl ce eat pe ee "pee a ea 2) 2 .-|/.-| 10) 18.80 = 1/78). .)..]- Ae ped aU Sees 1 Fa FY YP) Par 2) sates LOR 50 Cig=5= lee fae (Ao) en eel Eval ed eal Ns) tks fees ice soe Sele Oy bea A7-85|80}. .|. |. Byatt et | Se ef) eT eee rc Needed fee es 1} 1| 2) .-|--| 20) 18.80 C13-5-33/81]. |. .|. Dy De) Qype 1) 2). 2) 21) 23h 1 --|--| 14] 14. 43 W- 1/82)... .}. el | ate | ead | eed S| ee (| 3] 1} 1} 1] 2) 1 -| 1/..] 19} 20.16 C19-3-44)......... Aisa yj He pt Tia Ee ia Bd = Shoe 0) 10/20 7-19|84)._} 2) 1 Seas SN A a2 2 te 1 15) 12. 47 7-85|85}..|.-] 1 -| 3) LZ} 1) 2) 5}. -|2.) 2) 2) 1) 2) 1 19} 13.11 @21=5-33).-. 86). .].-]. De PL eR TTR ayy ele ee eee | ne em pe etd ES Hees eS eee ee Ola 3.90. A7-85)8 SPE eee eM cet eR eS peed ead) eth Ep teat) eile fora etal ge il ect cect om || ol Ol arn C21-5-47/89 2 3 Dy | a eS oh dH Fe Pct set eet eel ered peal eat feel feted (0) fn UAC) a Otalee. ae sea Wht) 9)12/29)33/58/50/75)66)75)84/79)72/57/61 Ab35\34)19)24 11 7} 3} 2) 2) 2)..| 1! 1/952) 14. 42 Among the females, B32-39 (Pl. XII) stands out in the 1910 test as a good parent for rust resistance. Unfortunately the progeny lot of seedlings B32-39 x A7-83 was in poor ground and did not show well in vigor compared to the open-fertilized lot which was in normal soil at the other end of the field. As was found in 1911, this apparent lack of vigor was due to poor ground only. The accompanying diagram (fig. 4) shows a comparison between A7-83 and A7-19, the two males used most in our pollination work in 1909, both in rust resistance and vigor transmission on the various lots of progeny from different females. Accompanying the records for each progeny is that of the check lot open-fertilized from the same females. This table shows strikingly the great advantage in using pedigreed seed of good parents. Attention is again called to the fact that the male plants available for pollination of the open- pollinated seed were, with few exceptions, select plants. 263 50 BREEDING ASPARAGUS FOR RUST RESISTANCE. PERMANENCY OF RUST RESISTANCE. A study of rust resistance year by year shows the same permanence of this character in the plants that was shown in the studies of size, , |AVERAGE HEIGHT OF SELEOLINGS \|\AVERAGE RUST RESIST IN INCHES ne FP SLEDLINGS Fic. 4.—Diagram showing the effect on greenhouse seedlings of 1910 of A7-19 and A7-83 with respect to the average heights and average rust resistance of progeny lots in comparison with the progeny from open-fertilized seed from the same female plants. yield, etc. Once the individual plants are learned, their individuality is recognized in different seasons. The attack of rust on the green- house seedlings in 1910 was very uniform and satisfactory from the 263 BREEDING. 51 standpoint of selection of rust-resistant plants. In 1911 the rust came on very much later and did not get started uniformly over the plat. Some lots were attacked as badly as in 1910, but the ends and outside rows where exposed to the wind and plants that were shaded by trees failed to show as much rust asin 1910. In spite of this fact, the correlation between the rust resistance for the two seasons of the individuals included in the tests of both years is quite high (Table XXIV). TaBLE XXIV.—Correlation between rust resistance in 1910 and in 1911 of greenhouse seedlings of 1910. [Resistance in 1910, subject; resistance in 1911, relative. Coefficient of correlation 0.512+0.015.] Rust resistance in 1911 (grades). Fre- Paper Resistance in 1910. quen-| fom 0 1 2 3 4 5 6 7 8 9 | 10 | °Y: | mean Grades: (Jt See 2 | EPS | [Sanne | Pease [A PN bape eye) oe eee er [Ateneo 1 1 Le ae Acree eee 2 —5 4 ees Sena aera] Lae = aap 3 1 asa 1 2 hl Pel SSS [eeenes 12 —4 eee ees 1 3 1 5 5 6 1 12 pi | ae a 36 —3 Bron een Ne aes 1 2 7 5 13 13 34 34 10s aces 119 —2 Ce ORS ae ORG asec) Rempel arses 3 5 7 12 47 38 23 3 138 —1 Dente es See Se ees [nome ciel ewe ciase 1 2 1 15 22 40 74 40 13 208 0 RE Get oonvel Geceee Seosee La geteace. 3 5 13 32 60 39 22 175 +1 eRe a Ree eae altos sacle sinc ais vee oof enero sie 3 5 20 52 39 19 138 +2 CO RES OIE Ee OP Sacer! (Ane SEIS at ess nec (Savane) [enete bares 1 9 19 29 26 84 +3 ee ea GG HO DI Ceo RO) BRU ISe CODES ceoees rte Mises eein| (eee lamer 4 9 14 27 +4 PY ye Oe onl asec Meee ee eee | Beams preter! [ected |r| | eee al 3 2 6 +5 Frequency... 1 dh 6 18 19 50 69 199 285 192 99 | 945 Departure from : WCa eee seen —8 —7 —6 —5 —4 —3 —2 —1 0 +1 Sl eee It should be noted that very few plants show greater rust in 1911 than in 1910. If the rust attacks had been of equal severity both seasons, a much higher value for the coefficient of correlation would have been obtained. As was shown in Table XXI, there is a definite relation between increase in size and rust resistance. The young seedlings in the greenhouse lot show- a relation between rust resistance and size, but to a certain extent the size is dependent even yet on the size of the seed. In Table XXV the heights in September, 1911, are correlated with the rust resistance of plants as observed in Septem- ber, 1910. The first 25 lots of the greenhouse seedlings were used in this table, as the rust attack in 1911 on this row was more uniform than on the other rows. 263 52 BREEDING ASPARAGUS FOR RUST RESISTANCE. TaBLE XXV.—Correlation between height in 1911 (inches) and rust resistance in 1910, row 1 of greenhouse seedlings of 1910. [Height in 1911, subject; rust resistance in 1910, relative. Coefficient of correlation 0.484+0.032.] Rust resistance in 1910 (grades). Fre- | Depar- Height in 1911. De i TET) a 1 2 3 4 5 6 7 8 9 10 mean Inches Oe Tat Pe a es Se Ete | ap eal eee ill bare Le 1 eel REE et) [Ese ey Ree bee hc SB re A 1 —9 Le etaiie shoes teicle ieee af hee A eee | emronore cell occ seis agen Diyos RA ee ee ea ee 1 —8 TIL AS Me re eset ta a i |e UR) Foes iy [eee ewan | Here A 18) gc 3 —7 P71 a ee ie eA SPO Da 16H [Siaiaas [ees 1 Sn RE Lee 1 eee (eb sie Le 6 —6 nae Seapets ata tre ESS 1 Se ae Eee 7h) PR ah haere sale INE Hy hah 2S 4 —5 DIRE R San dee oe eee 3 2 2 6 Drew 8. Mie tah Dae oe 18 —4 SOME ee clen an ee ne ti 1 5 5 7 7 2 PA Ae: hs) |e 29 —3 Be apne sre abet ae ad ae arial Nar a Ba ea 2 2 2 9 5 8 3 2 2 34 —2 DOP bale aee Baan al we 2 1 1 3 8 11 8 A Ne de 38 —1 BO eee Cite eee See nl rel Benen 3 iD eee a 7 11 12 8 1 NP) Re ae 43 0 fe RUS Ute MAD eae hore ash ten We, | Hal es Clea i 1 7 6 13 aye ue 1 32 +1 CE EATS ee Va aa Seana | LLANE 2 eM 1 5 9 3 PAS Feel Hel 20 +2 TAS eM span os Sh cyanea Calan rcv (apa ane Pee 1 3 2 3 4 3 1 17 +3 Fa) UNS ORE age eer ene iy a Deca 2 4 1 2 3 3 16 +4 I ees eT Se cH Ra eg a hoe | aoc ete es (Sra SE ree 4 1 Ga, beset le 6 +5 CR eC Ge Re ad TS Tey Lf ACG eA Ne PE Fe S| Fa NT oa el (a 1 1 +6 IS ares ele ANS, ill AL ee Re Sa eo A ane gu a el 1 1 2 ae 3 +7 [oF Sep anes AOSD ene ve PARA a| Ni) BS 20 | | PR [eR NOt ar Ste 13] eee 1 +8 Rrequency;. shee" 8 12 14 16 54 60 61 32 14 7| 273 Departure from mean..-.| — 5 | — 4] — 3 | —2|—1 Oo; +1}+2)/+ 3) 4+ 4}-----.- SEEDLINGS OF 1911. Tn 1910 the work of making pedigree combinations was continued in the spring months. This work was done before the rust developed and was naturally of a more or less hit-or-miss character. Male plants were selected for their individual qualities with the hope that they would transmit these qualities to their offspring. A7-19 and A7-83 were used as check males to test new female plants. The female plants that had given the best resistance both in 1908 and in 1909 were also used in making combinations with these males with the plan that if any of the 1909 combinations showed desirable resistance the 1910 lots of seed would furnish an additional supply of the desir- able progeny. The seed resulting from these pollinations was planted in 1911 at Concord, and when the rust attack developed in August the behavior of the different progenies was much the same as in 1910. A7—-19 proved to be a failure in point of transmission of rust resistance and has been discarded. A7-83, however, again performed in a very satisfactory manner. Its progeny proved highly resistant to rust and very vigorous in comparison with seedlings from American stock lacking in rust resistance. Plate XIII shows a row of seedlings from plants in row B24 (fig. 1) compared with the best resistant progeny “Martha Washington” (fig. 2). The striking difference in the two photographs is not so great as the contrast in the field, where the rich green of ‘‘Martha Washington” contrasts with the gray brown . the dead seedlings from row B24. 263 Bul. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XIII. ian. 191.171 jG Fia. 1.—WAKEMAN SEEDLING STOCK, SHOWING TOPS ENTIRELY KILLED BY RUST. (Photograph taken September 25, 1911.) Fig. 2.—"" MARTHA WASHINGTON” STOCK (PROGENY B32-39 X A7-83), COMMERCIALLY IMMUNE PLANTS OF STRONG ViGoR. (Photograph taken September 25, 1911.) PEDIGREE SEEDLINGS OF 1911 AFTER A SEVERE ATTACK OF RUST. Bul. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XIV. PEDIGREE SEEDLINGS OF 1911 AFTER A SEVERE ATTACK OF RUST, SHOWING VARIABLE RESISTANCE OF STANDARD GIANT ARGENTEUIL, ALL PLANTS SUFFERING FROM RUST. , 1911.) 5 9 (Photograph taken September Bul. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XV. PEDIGREE SEEDLINGS OF 1911 AFTER A SEVERE ATTACK OF RUST, SHOWING PLANTS FROM STANDARD READING GIANT SEED, SOME NEARLY IMMUNE, OTHERS RUSTY. 5, 1911.) (Photograph taken September : Bul. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XVI. 7-83 ON A FEMALE PLANT (A2-23) oF PEDIGREE SEEDLINGS OF 1911 AFTER A SEVERE ATTACK OF RUST, SHOWING THE EFFECT OF CROSSING A AVERAGE RESISTANCE. 1011 \ {= (Photograph taken Sentemher 9 PLATE XVII. Bul. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. Ativnasn ‘68-3& CTI6L ‘ez Joquiejdag udyR} ydrisojoyd ) "YODIA NI ONINOV7] LNd LNVLSISSY ALINO gq 30 gaag G3ZIMILYS4-N3dO WOYS SLNV Id SNIMOHS ‘SLSNY JO HOVILY SYSARS V YaLSAV LIL6L 40 SDONIIGASS S3ayudIdad Bul. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE XVIII FIG. 1.—SEEDLINGS AT THE SOUTH END OF A BED AT CONCORD, MASS., IN AUGUST, 1910, JUST BEGINNING TO RusT. Fic. 2.—SEEDLINGS AT THE NORTH END OF THE BED SHOWN IN FIGURE 1 ON THE SAME DAY, SHOWING THE DESTRUCTION OF PLANTS CAUSED BY THEIR PROXIMITY TO A YOUNG BED ON WHICH CLUSTER CuPS DEVELOPED ABUNDANTLY. EFFECT OF RUST ON ASPARAGUS SEEDLINGS. BUD PROPAGATION. 53 Photographs do not show the dead color of plants injured by rust, but in Plate XIV the effect of the 1911 rust attack is shown on American-grown Argenteuil stock, and Plate XV shows American- crown Reading Giant stock in an adjoming row. There is no ques- tion that Reading Giant contains plants of greater resistance than any to be found in any lot of Argenteuil grown on the station grounds at Concord. Plates XIV and XV show this difference about as it occurs in the regular field growth of the two stocks. The seedlings from A7—-83 progenies are superior to these standard strains in both rust resistance and vigor (Pl. XVI). B32-39 gives very resistant seedlings even when open fertilized with males of medium resistance (Pl. XVII). The small size of the seeds of this plant places the seedlings at a dis- advantage, and the combination with A7-83 is needed to give vigor. Tn the tests of 1911 no new progeny lots showed a resistance or vigor comparable with that of ‘Martha Washington.” Most of the plants tested will be discarded, a few females being held for a further test. New selections from Reading Giant and from A7-83 progeny are included in the pollination work in 1912. Some of these new selec- tions show such a high individual resistance that it is practically cer- tain that some of the new combinations with A7-83 will show great resistance. BUD PROPAGATION. In order to increase the product of seed from individual plants it will be necessary to carry out some methods of vegetative propaga- tion. Preliminary experiments to this end were undertaken in the greenhouse in 1910. Seedlings planted January, 1910, were separated when they had several shoots; the roots were divided more or less evenly and the plants repotted. Nearly all of them grew, and in about a month they were separated again. This was kept up until in January, 1911, two seedling plants were represented by 60 or more plants. When properly handled few plants die. In the fall of 1910 about half the crowns of No. 1 Washington, No. 2 Martha, B32-4, and A2—23 were dug up, shipped to Washington, and planted in the green- house. These crowns were split into several smaller clusters and planted in 12-inch pots. New shoots started, but on account of low temperature did not completely develop, and finally died back. When the pots were moved into a warmer house the divided crowns started growing again, and some of the plants have been divided a second time. This method of vegetative propagation will be neces- sary in breeding and seed-growing work. PEDIGREE. In pedigree breeding work the performance of the parent indi- viduals is not important in itself, and is only of value as it shows the ability of the plant to transmit its good qualities to its offspring. 263 : 54 BREEDING ASPARAGUS FOR RUST RESISTANCE, These plants selected for breeding purposes become valuable only as their progeny show uniformly high quality and yield. So when a pedigreed progeny shows a high commercial value its parent plants become of great importance. They should be increased as fast as possible by clonal propagation and should be isolated and allowed to produce as much seed as possible. It is now that records and history become important. Careful record should be kept of their original source, etc., and future development. In carrying out the work on this breeding project and of private breeding work developing from it the following scheme will be used: Number.—Each plant that proves of value as a breeding parent will be assigned a permanent serial number. These numbers will not be given to a plant until its progeny show it to be of value as a breed- ing parent. Its preliminary records will be kept under a temporary number used to mark its location in the testing plat. Name.—Plants used to produce progenies for commercial planting will be given names as follows: The male plants will be given sur- names as Washington, Wilson, Prescott, Wheeler, Moore, etc., the name assigned to one plant not to be duplicated in the future. Female plants will be named by assigning them different feminine names, as Martha, Mary, Edith, ete. Progenies will take their commercial or trade names from the two parents. Thus the progeny of No. 2 Martha X No. 1 Washington will be known to the trade and growers as ‘‘Martha Washington”; No. 3 Edith x No. 1 Washington would be ‘‘Edith Washington”; No. 2 Martha x No. 4 Wheeler would be ‘‘Martha Wheeler.” In this way each progeny would by its name indicate its parents. Records ——In keeping pedigree records the loose-leaf record book will be used. A primary sheet for each parent admitted to registry will be used, giving its history, description, ete. The performance of the plants as shown by their progeny records will be filed under the female parent as secondary sheets. An abbreviated record of these progeny sheets will be filed under the male parents as secondary sheets to show the performance. No. 1. Washington ¢. Pedigree: Q unknown. g unknown. History: Original plant found in 1908, location A7-83. New American Concord- grown stock by Anson Wheeler. Marked as best male in type and rust resistance. Used in 1909 and 1910 in crossing work. In 1911 used as test male in all crossing work. Progeny: Very resistant to rust and showing an added vigor above open- fertilized progeny no matter what female parent was used. Propagation: Part of original parent dug up in 1910 for clonal propagation. 263 PLANS FOR DISTRIBUTION, 55 No. 2. Martha 9. Pedigree: 9 unknown. g unknown. History: Original plant found in 1908, location B32-39. Reading Giant stock. Marked as best in rust resistance 1909; rather small type; used in 1909 and 1910 in crossing work. In 1911, under cage, crossed with No. 1. Progeny: Open-fertilized lots of 1909 and 1910 better in resistance than any other open-fertilized lots tested. XX No.1 progeny best for resistance and type of any seedlings grown. Propagation: Part of original parent dug up in 1910 for clonal propagation. When plants from any named progeny develop as good breeding parents they will be assigned new names and handled as distinct parents, their history and pedigree being recorded on their original pedigree sheets. When by vegetative propagation the original parent plants have increased so that different growers have lots of the same progeny, in offering them for sale the grower’s name should accompany the progeny name for purposes of identification in case any error creeps in; as, Martha Washington (Frank Wheeler stock), Martha Washing- ton (C. W. Prescott stock). The registry of new parents for breeding purposes should be through a central breeding organization, so that no duplication of names will occur. For the present this work can be done at the experimental station at Concord. These new progeny lots must be tested in competition with some standard progeny of known rust resistance and quality and their general value determined. PLANS FOR DISTRIBUTION. When sufficient stock of any progeny is obtained to warrant dis- tribution to interested growers, plans will be made to plant the stock under conditions favorable to the satisfactory testing of these prog- enles for resistance to rust. The lots of seed or seedlings issued by the Department will, as far as possible, be sent to growers who will be in a position to aid in extending the cultivation of the rust-resistant strains. SUGGESTIONS TO BREEDERS AND GROWERS. In giving advice in regard to asparagus breeding at this time it must be remembered that our experiments are only just begun. Later results are liable to change the methods of procedure to be recommended, but the methods and practices at present followed are here outlined. RUST RESISTANCE. If rust is a factor in the region where the work is to be done, resist- ant varieties are of prime importance. In order to secure resistant selections rust must be present in abundance. Unless one can pick 263 56 BREEDING ASPARAGUS FOR RUST RESISTANCE. the one superior plant out of a thousand in point of rust resistance the work will be hard. Late fall is the best time for making field selections, because at that season the rust will be developed sufficiently to have marked the nonresistant plants in the field so that they can be disregarded. In providing rust for this work in New England it will usually be sufficient to leave an area of nonresistant plants in one corner of the field, preferably that from which the prevailmg winds come. If there was plenty of black rust the preceding season, the spring stage will develop in sufficient abundance to provide rust for infection work later in the season.