- . . ; : : L'l B RAR.Y OF THL UNIVERSITY Of ILLINOIS cdp. 2 A9RICULTUM NOTICE: Return or renew all Library Materials! The Minimum Fee for each Lost Book is $50.00. The person charging this material is responsible for its return to the library from which it was withdrawn on or before the Latest Date stamped below. Theft, mutilation, and underlining of books are reasons for discipli- nary action and may result in dismissal from the University. To renew call Telephone Center, 333-8400 UNIVERSITY OF ILLINOIS LIBRARY AT URBANA-CHAMPAIGN APR 11996' L161 O-1096 A M1DSEASON SOYBEAN For the North -Central States By C. M. Woodworth and L F. Williams #8*P^l|t i M Wi ""**- /*-. Bulletin 520 UNIVERSITY OF ILLINOIS AGRICULTURAL EXPERIMENT STATION In cooperation with Bureau of Plant Industry, Soils and Agricultural Engineering, U. S. Department of Agriculture CONTENTS Page Plant and Seed Characteristics 335 Origin and History 337 How Lincoln Compares With Other Varieties 338 Lincoln Performs Well Over Wide Area 343 Occurrence of Black Seeds 344 Summary and Conclusions 347-348 AUTHORS C. M. WOODWORTH, Chief in Plant Genetics (in charge of plant breeding in Agronomy) ; and L. F. WILLIAMS, Asso- ciate Agronomist, Bureau of Plant Industry, Soils and Agricultural Engineering, U. S. Department of Agriculture. FRONT COVER Photograph shows an increase plot of Lincoln soybeans on the Agronomy south farm of the University of Illinois. Dr. Woodworth and Dr. W. L. Burlison are inspecting the beans. Urbana, Illinois January, 1947 Publications in the Bulletin series report the results of investigations made or sponsored by the Experiment Station. LINCOLN: A Midseason Soybean for the North-Central States By C. M. WOODWORTH and L. F. WILLIAMS E^COLN is the most promising midseason variety of soybean developed to date. It is outstanding in yielding ability, percent- age of oil, and seed quality, and is above average in resistance to lodging. Because it is adapted to a wide range of soils and climate, it should occupy a large part of the soybean acreage in the North-Central states. Plant and Seed Characteristics The Lincoln plant has brown pubescence (soft, short hairs on surfaces of leaves and stems). The flowers are white. In growth habit it is "indeterminate," that is, the stem is terminated by one pod rather than by a cluster of pods. The seeds are round and yellow with a prominent black hilum, or eye. Both plant and seed closely resemble the Manchu variety and a number of Manchu selections. In field appear- ance, height, lodging resistance, time of maturity, and number of seeds per pod, Lincoln most closely resembles Mandell. The white flowers, however, distinguish Lincoln from Mandell and other commonly grown varieties with brown pubescence. Lincoln increase field on Agronomy south farm at the University of Illinois. Pods are well set and seeds are developing. Plants are about 36 inches high (stake is marked with 1-foot sections). (Fig. 1) m 336 BULLETIN No. 520 [January, Since Lincoln is so similar in appearance to Manchu, Mandell, Mingo, Harman, Scioto, and other Manchu selections it is not advis- able to grow Lincoln for seed on the same farm with any of these varieties. When there is any doubt as to the identity of seed lots, how- ever, Lincoln can be distinguished by germinating the seed. The hypo- cojyl, or neck, of the Lincoln seedling, like that of other white-flowered varieties, is green as it emerges from the ground. Manchu strains and other purple-flowered varieties have purple hypocotyls. Varieties commonly grown have the following characteristics: Pubescence Flower Hilum Variety* color color color Earlyana Brown Purple Colorless b Wisconsin Manchu 606 Brown Purple Black Wisconsin Manchu 3 Brown Purple Black Richland Gray Purple Pale slate Mukden Gray White Light brown Mingo Brown Purple Black Black Hilum Manchu Brown Purple Black Dunfield Gray White Light brown Lincoln Brown White Black Illini Gray White Light brown Viking Brown Purple Black Chief Gray Purple Imperfect black a Arranged according to maturity. b Brown spot at end of hilum. Lincoln soybeans just before harvest. Altho these beans are leaning slightly, the Lincoln variety usually stands well and combines easily. Rich- land is the only soybean that exceeds Lincoln in lodging resistance. (Fig. 2) 1947] LINCOLN: A MIDSEASON SOYBEAN 337 Origin and History Lincoln originated from a natural cross between Mandarin and Manchu made in 1934 by C. M. Woodworth at the Illinois Station. In making this cross, a modification of the interplanting method suggested by G. H. Cutler of the Purdue Station 1 was followed. In every other row Mandarin, used as the female plant, was interplanted with Manchu. Alternate rows were planted to pure Manchu. This arrangement gave maximum chances for natural crossing of these two varieties. The Mandarin seed from the 1934 crossing plot was planted in the nursery in 1935, and the natural crosses were picked out at maturity. Since the brown pubescence of Manchu is dominant to the gray pubescence of Mandarin, the hybrid plants could be detected by their brown pubescence. The F 2 progenies were grown in 1936 and selections were made from them. In 1937 a number of the 1936 selections were grown in plant rows. From the 1937 plants further selections were made for plant rows in the 1938 nursery. In 1937, also, the better plant rows were selected for a replicated yield test in 1938. Strain L6-685 yielded more than any other strain in the preliminary test that year and so was included in a group of early strains tested in 1939 at Holgate, Ohio, and at three locations in Illinois. Again in 1939, L6-685 was the highest yielding strain at the four locations where it was tested. Consequently it was entered in the 1940 Uniform Group IP tests, which were conducted at nine locations in Ohio, Indiana, Illinois, and Iowa. That year it was exceeded in yield only by a sister selection, L6-12. The following year (1941) L6-685 exceeded all other strains in the Uniform Group II tests, as well as in the Ohio variety trials and the Iowa Elite tests. In 1942 it again ranked first in Group II, and also in Group III, in which it was entered for the first time. In the spring of 1943 a conference of state and federal soybean workers, meeting at the U. S. Regional Soybean Laboratory, decided to call the new variety "Lincoln." In 1943 Lincoln ranked first in yield 1 CUTLER, G. H. A simple method of making soybean hybrids. Jour. Amer. Soc. Agron. 26, 252-254. 1934. 1 The U. S. Regional Soybean Laboratory, in cooperation with state experi- ment stations, has sponsored a program of cooperative Uniform Soybean tests. In these tests the strains are divided according to maturity into nine groups, designated as 0, I, II, III, IV, V, VI, VII, VIII. Group II comprises strains that are between Earlyana and Mukden in maturity, and Group III includes strains maturing between Alukden and Patoka. 338 BULLETIN No. 520 [January, in Group II but was exceeded in Group III by Chief and C56. In 1944 it ranked first in both Group II and Group III. Table 1 shows com- parable yields of L6-685 and other strains for each year, 1938 to 1944. All seed used since 1939 traces back to the best 1938 plant row, which was chosen for increase to carry on the line. Plants in this row seemed so uniform that no further selection was made. Altho the original cross was made in Illinois and the selection work and early testing were also done there, .much of the later testing and increasing of seed has been done elsewhere. Seed increase was started in 1941 at Columbus, Ohio, and was greatly expanded in 1942 in Iowa, Illinois, Indiana, and Ohio. In 1943 Nebraska and Missouri also grew seed increases. That year all seed production was controlled by the state experiment stations, but sale of the 1944 crop was unrestricted except for a general agreement to keep prices at reasonable levels. Had it not been for the Uniform Group tests, conducted by the Regional Soybean Laboratory in cooperation with state experiment stations, Lincoln would not be in the hands of producers now. Lincoln is the first soybean variety to be increased and released cooperatively and simultaneously by several states, and it is hoped that this procedure may prove to be a pattern for future development. Many test plots are in the fields of farmer cooperators, and a good share of the credit for evaluating this new variety goes to these men who have made this testing possible. , How Lincoln Compares With Other Varieties Since Lincoln has been so extensively tested in the Uniform Group tests, as well as in numerous state soybean tests, more comparative data are available for this variety than for most new strains. Per- formance of Lincoln in the Uniform Group II tests during five years Table 1. Yields of Eight Soybean Varieties in the Uniform Group II Tests, 1940-1944, and in Preliminary Tests in 1938 and 1939 (Bushels per acre: figures in parentheses indicate number of tests) Variety 19; (1 18 ) 19' (3 19 ) 19^ (9 to ) 19< (11 U ;) 1942 (13) 1943 (18) 1944 (16) Lincoln (L6-685) 39 7 SI 4 28 4 33 1 40 4 33.6 34.0 Mingo 38 7 26 28 6 33 9 30 3 30 6 Illini . 33 9 44 4 25 4 28 4 33 4 30 31.7 Dunfield . 27 ? 39 4 23 1 27 Q 32 8 28 7 28 5 M ukden 37 4 41 ? 21 ? 25 1 31 8 29 5 29 1 Richland 35 6 36 8 23 ^ 23 31 28 5 27.8 20 S 23 ? 31 4 28 5 26 7 Wisconsin Manchu 3 . . 33 3 33 ?. 19 5 73 4 30.4 25.8 27.4 1947] LINCOLN: A MIDSEASON SOYBEAN 339 and in the Uniform Group III tests for three years is summarized in Tables 1 to 5. The Group II tests of midseason and early varieties have been con- ducted in the northern and central sections of Iowa, Illinois, and Indiana, northwestern Ohio, the northeast section of Nebraska, and the southern parts of Wisconsin and Michigan. These varieties have also been tested in New Jersey. Lincoln's superiority in yield of seed over other Group II varieties is shown by Table 2, in which varieties are arranged according to yield. Producing 17 percent more beans per acre than the average of the widely grown Dunfield and Illini varieties, Lincoln has ranked first at all locations except Cherokee and Kanawha, Iowa, where it ranked second. Lincoln has also excelled in seed quality, percentage of oil, and Table 2. Yields of Eight Soybean Varieties in the Uniform Group II Tests, 1940-1944 (Bushels per acre) Hoi- Michigan Indiana Illinois Variety Average of 65 tests gate, Ohio 1940- 1944 Dear- born 1941- 1943 Lans- ing 1943- 1944 La- grange 1942- 1944 Bluff- ton 1940- 1943 LaFay- ette 1940- 1944 Wana- tah 1940- 1944 Mt. Morris 1942- 1944 Dwight 1940- 1944 Lincoln 34.1 30.1 29.9 28.2 27.5 27.0 26.2 25.7 28.6 17.4 27.1 24.1 22.8 21.6 20.4 21.1 21.7 21.2 22.5 22.1 36.7 30.0 35.3 24.9 29.6 22.8 30.0 27.5 29.6 21.9 27.8 24.2 23.3 20.0 23.1 18.8 20.8 21.6 22.5 28.4 28.0 25.1 25.6 23.7 24.0 21.8 21.3 22.3 24.0 13.6 39.3 33.2 34.0 30.8 30.9 29.5 29.1 26.9 31.7 21.3 44.9 38.6 37.8 33.6 37.2 32.3 30.9 31.4 35.8 25.8 27.0 24.2 25.0 23.6 22.5 21.4 22.5 19.1 23.2 11.1 20.0 18.3 18.1 17.5 17.0 16.0 17.8 17.2 17.7 12.4 33.9 27.8 29.8 27.9 26.8 26.6 24.7 24.8 27.8 17.5 Mingo Illini Dunfield Mukden Earlyana Wisconsin Manchu 3 " Average Percent Lincoln was above Illini- Dunfield average Variety Illinoii 3 (continued) Madi- son, Wis. 1943- 1944 Iowa Norfolk, Nebr. 1943- 1944 Urbana 1940- 1944 Ston- ington 1940- 1941 Clay- ton 1940- 1941 Hud- son 1942- 1944 Ames 1942- 1944 Kana- wha 1940- 1944 Chero- kee 1942- 1944 Lincoln 42.0 37.1 34.4 35.4 32.9 34.1 28.6 29.6 34.3 20.3 28.3 25.8 25.7 25.7 20.5 20.6 19.4 20.7 23.3 9.2 34.0 31.1 27.0 30.9 23.1 27.2 21.2 23.7 27.3 17.4 39.4 35.1 34.3 32.9 34.2 28.4 29.4 29.9 33.0 17.3 41.3 34.8 37.5 34.9 35.7 33.1 33.4 33.2 35.5 14.1 44.1 40.3 38.7 38.8 39.6 38.1 36.8 34.5 38.9 13.8 30.4 29.5 28.7 27.2 27.4 28.7 30.6 29.0 28.9 8.8 43.5 39.9 47.2 39.0 36.7 37.7 38.0 34.7 39.6 .9 33.8 28.3 29.8 26.5 28.0 29.4 29.7 27.1 29.1 20.1 Mingo Illini Dunfield Mukden Richland Earlyana Wisconsin Manchu 3 Average Percent Lincoln was above Illini-Dunfield average.. 340 BULLETIN No. 520 [January, iodine number of the oil, and has been exceeded in lodging resistance only by Richland (Table 3). Several inches shorter than Illini, Lincoln is about the same height as Mingo, Dunfield, and Mukden. The seed is larger than that of Illini and about the same size as Mukden seed. Lincoln has required an average of 129 days to mature in these tests. This is about the same time required by Mingo, Illini, and Dunfield, and about 4 days more than needed by Mukden. Table 3. Summary of Agronomic and Chemical Data for Eight Soybean Varieties in the Uniform Group II Tests, 1940-1944 (Figures in parentheses indicate number of tests) Variety Average acre yield (65) Lodg- ing rating* (60) Height (55) Matu- rity index b (58) Seed qual- ity" (54) Weight of 100 seeds (64) Protein con- tent" 1 (69) Oil con- tent 11 (69) Iodine No. of oil (69) Lincoln bu. . 34.1 2.2 inches 37 1.4 grams 15.0 perct. 40.7 Perct. 21.1 136 Mingo . 30.1 2 9 36 .6 2 15 7 42.9 19.9 134 Illini . 29.9 2.9 40 + .8 1 .5 13.9 40.8 20.0 134 Dunfield . 28 2 2 8 36 + 2 1 5 15 9 40 1 20 5 130 Mukden . 27.5 2.2 37 3 7 1 6 14.9 43.9 19.5 130 Richland . 27.0 1.5 31 -6.4 1 .7 16.3 41.1 20.2 128 Earlyana . 26 2 2 5 35 10 7 2 14 8 43 6 20 2 132 Wisconsin Manchu 3 . . Average . 25.7 . 28.6 2.8 2.5 32 35.5 -7.5 2.2 1 .7 16.9 15.5 42.6 42.0 20.0 20.2 133 132 Based on a scale of 1 to 5: 1 is erect; 5 is completely lodged. b Days earlier ( ) or later (+) than Lincoln. Lincoln required 129 days to mature. c Based on a scale of 1 to 5 : 1 is very good ; 5 is very poor. d Composition on a dry basis. Protein = NX6.25. Lincoln has also performed well farther south, in the Uniform Group III tests, for several years. These tests have been made in central and southern Indiana, central and southern Illinois, central Missouri, central Iowa, and eastern Nebraska. Lincoln has required an average of 119 days to mature in these tests - 10 days less than in the Group II tests. This difference is due to the fact that the Group III tests are made under higher temperatures. In yield, lodging resistance, seed quality, and percentage of oil Lincoln has been outstanding in the Group III tests, as it was in the Group II tests. Lincoln has averaged 18 percent more beans per acre than the average of Illini and Dunfield in the Group III tests, the increase rang- ing from 29 percent at Greenfield, Indiana, to .6 percent at Lincoln, Nebraska (Table 4). In the southern parts of the Central states Lincoln is evidently just as superior to these other two midseason varieties as it is in the northern sections. Lincoln has also outyielded Chief at every location in the Group III 1947] LINCOLN: A MIDSEASON SOYBEAN 341 1 1 i-^ S S2SS S a I icd ^, ^^^^ ^ < || 9 assis s a 1 _c I [ 1 | i| n j^S s 2 "e i C. > j I > 4 . N' 2^a 2 4 4 Q s 4 c J, o ** OvO^O O\ O 5 >> oo \o in t^ fs in -^ > fv) CS CS fS CN CS -H > c o 1 'o M ^* t^* CS 00 O\ O ?S 4 | ts HH 'S O ^^ oo in oo O o* 1/5 csts CN m cs 1 Cfl ) ^ bt V 3 m \o \o m oo oo i ) UJ rri -r -t t - C 00 <*) tr> m ts CN r<5 cs 4 " 0! a J c cd O* in ^^ oo ^o cs c^ J ~ < CO 1 s 2 "3 oo mo>o m * 4 s -* o'ojvo'^ a 3 J >> ndiana O D 3 -* 4) O o> oomoo oo oo 2 rt" H >e if> O >O m tl4 ^ ~*~. "~.~''. ~^. f} c^ L> is > j _ 4 " 2^ \o N ^ o> ^* m o 3 s i oioO'O'O 00 oo > v > -M 5 MM "3 > o c Ji T3 Sf = C i -oiL i P q 2 -JJ .S