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|Title:||Studies on Plant Height and Flowering Date and Their Effect on Seed Yield in Determinate Soybeans (Glycine Max)|
|Department / Program:||Agronomy|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||There has been an increasing interest in growing determinate soybeans Glycine max (L.). Merr. in the northern U.S. because of their yielding ability and lodging resistance. Two experiments were conducted to (1) estimate the heritability of days to flowering (R1) and maturity (R8), and plant height at these two stages; (2) evaluate the relationships among the traits; and (3) study the value of plant height and flowering date in improving seed yield for determinate soybeans. Both experiments were carried out on the Agronomy-Plant Pathology South Farm at Urbana, IL in a Flanagan silt loam (Aquic Argiudoll).
In the first study, two exotic, determinate populations (containing 42 and 42 F(,2) families) were evaluated for R1, R8, and plant height in the F(,3) and F(,4) generation in 1984 and 1985, respectively. A randomized complete block design with two replications was used for each population each year. Heritabilities estimated by parent-offspring regression were high (0.67 to 1.21) for R1, R8, and plant height at these two stages except for R1 in one population (0.49). Genotypic and phenotypic correlations between R1, R8, and plant height indicated selection for tall determinate plants with early flowering would be difficult. Selection for plant height could be carried out as early as R1 stage for determinate soybeans.
In the second study, twenty F(,2) families representing four plant types: tall, early flowering; tall, late flowering; short, early flowering; and short, late flowering were identified in the F(,3) generation for each of maturity groups I through III. They were yield tested in 1985. The experimental design was a randomized complete block with two replications and a split-plot arrangement of treatments. Seed yield was significantly affected by height in group II, where short plants yielded 6% more than the tall; and by time of flowering in group II and III, where early flowering plants outyielded the late flowering by 25% and 23%, respectively. The highest mean yield and highest yielding families were the short, early flowering type for all three maturity groups. The highest yielding F(,2) families were taller than currently grown determinate cultivars.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1986.
|Date Available in IDEALS:||2014-12-16|