GREENHOUSE AND FIELD-EVALUATION OF POD DEHISCENCE IN SOYBEAN

A greenhouse procedure to evaluate differences among soybean [Glycine max (L.) Merr.] genotypes for pod dehiscence (shattering) susceptibility permits evaluation under controlled environments. Suitable environmental conditions do not always exist in the field. The objectives of this study were to develop a greenhouse method to screen for shattering susceptibility and to compare genotypes for shattering resistance under both greenhouse and field conditions. Eight genotypes were evaluated in both the field and the greenhouse. A split-plot treatment design in the greenhouse included watering plants after physiological maturity versus no watering after maturity as a whole-plot factor, with genotypes assigned to split plots. In the greenhouse, shattering susceptibility was not reduced by watering after physiological maturity. The genotypes most susceptible to shattering were identified on the basis of the greenhouse and field evaluation. Among the specific genotypes evaluated, the earliest maturing genotypes were not the most susceptible to shattering.