Sunflower Seed Physiological Maturity.

Determination of sunflower seed physiological maturity is important in crop preharvest management and harvest timeliness. The study objective was to determine seed moisture content at physiological maturity. Sunflower hybrids were evaluated in field studies at Prosper, ND, and Morris, MN, in an RCBD with four replicates during the 2008 season. A nonoilseed, NuSun, and high oleic sunflower hybrid were the main plots with seed harvest date the subplot. Seed harvest dates began at growth stage R6 and continued at 5 d intervals until seed moisture was approximately 200 g/kg. First year results and preliminary analysis indicated maximum seed weight occurred between 280 and 480 g/kg seed moisture.