Research Article
Berger-Doyle J, Zhang B, Smith
Abstract
A niche market for food-grade soybean varieties has emerged in the United States in recent years. However, knowledge of optimal management practices for new varieties of food-grade soybean in the southern United States is currently lacking. Therefore, the objectives of the study were: 1) to determine favorable production practices for current specialty soybean cultivars; 2) to determine heritability of major agronomic traits in multiple environments; and 3) to determine correlations among these traits in specialty soybean. Several agronomic traits of eight soybean genotypes, representing tofu, natto, and conventional varieties currently available in the southern United States, were assessed with three variables: planting date (April, May, and June), irrigation treatment (irrigated and dryland), and row spacing (narrow and wide). Yield, seed size, maturity, plant height, lodging, shattering, and stand count were measured after maturity. Among planting dates, the May planting resulted in the greatest yield and height; whereas varieties planted in April were the shortest and produced the lowest yield. June plantings resulted in longer days to maturity. Irrigation improved yield and extended days to maturity. Row spacing did not have a significant effect on yield, seed size, maturity, or plant height. Among all environments, seed size was highly heritable, and yield heritability was relatively low. Yield and maturity were negatively correlated, yield was positively correlated with height, and maturity was positively correlated with seed size. These results can be used to optimize specialty soybean seed production in the southern United States.