Individual Rice Kernel Moisture Content Variability Trends1

Kernel-to-kernel moisture content (MC) distributions on panicles were measured for rice cultivars Bengal, Cypress, and Drew. Rice panicles in Arkansas were harvested at different stages of maturity from foundation seed fields at two locations with widely varying soils during the autumns of 1998, 1999, and 2000. The objective was to quantify variability of individual rice kernel MCs as affected by cultivar maturity, planting location, and year. Individual kernel MC distributions were multi-modal until the average harvest MC (HMC) reached about 16%, at which point the distributions tended to be primarily single-modal. For all cultivars, kernel MC standard deviation (SD) decreased as HMC decreased. Bengal MC SD was affected by HMC. For Cypress and Drew, individual kernel MC SD was significantly affected also by year, location, and interactions of HMC*year and HMC*location. Regression equations that accounted for the variation in individual kernel MC at varying kernel maturity stages were generated for each cultivar.