Determining Type of Sterility, Thresholds, Seeding Date and Rates of Arkansas Male Sterile Lines for Hybrid Seed Production

Two-line hybrid rice production requires environmental genetic male-sterile (EGMS) lines that become sterile in certain conditions. In this study, we aimed to identify the type(s), sterility thresholds, optimum planting date, and efficient seeding density of eight lines, including four developed at University Arkansas, Rice Research Extension Center (RREC) Dale Bumpers National (DBNRRC) both located Stuttgart, AR, USA. The were screened growth chambers using different temperatures day lengths type EGMS line thresholds. A single location was used testing first year study three locations second date study. All experiments arranged randomized blocks with replications rate. Three dates tested each for experiment, densities seed chamber showed all RREC thermosensitive genic threshold temperature one these >32.2 °C while others >29.4 °C. DBNRRC inconclusive due their heterogenicity response inconsistency. April 25 conditions, a 431 seed/m2 rate required produce an adequate number panicles avoiding wasting expensive seeds.