Evaluating a Chemical Male Gametocide Under Field Conditions in Grain Sorghum.

Sorghum bicolor is a self-pollinated species grown as both a pure line or hybrid cultivar depending on the economics of the production region. For improvement purposes, multiple methods of hybridization are needed for both breeding and seed production systems. To make breeding crosses, several different methods have been developed, but none of them produce completely male-sterile plants that can produce a full panicle of hybrid seed. This study investigated the use of a chemical male gametocide to produce temporally male-sterile sorghum panicles. A chemical male gametocide was applied at four doses, 10,15, 20, and 30 mg/plant in a single application, while a second and third application of 10 mg/plant was applied to a subset of those plants at the Texas Agrilife Research Farm near College Station, Texas, during the 2017 growing season. A preliminary study conducted during the 2016 growing season showed significant effects for both dose and application.