Agronomic performance of soybean [Glycine max (L.) Merr.] hybrids
Male sterility systems identified in soybean [Glycine max (L.) Merr.], combined with insect-mediated cross-pollination have been shown to produce large quantities of hybrid seed that can be useful for the identification of heterotic patterns in soybean. This procedure was used in this study to produce hybrid seed for the conduct of replicated yield trials. The objectives were: (1) to evaluate yield in hybrid soybean populations developed by single-crosses, three-way crosses, four-way crosses, five-way crosses, and backcrosses (BC1, BC2, and BC3), and (2) to estimate heterosis for yield, and other agronomic characteristics of the hybrid populations. Parental genotypes were male-sterile lines and a group of male parents selected for their agronomic performance. The few positive high-parent heterosis (HPH) and mid-parent heterosis (MPH) values obtained, suggest that many cross combinations need to be evaluated before heterotic combinations can be identified that will determine the feasibility of commercial hybrid soybean production.