Rice Kernel Dimensional Variability Trends

Rice kernel dimensions affect the performance of various post-harvest processes. This study assessed variability trends in kernel dimensional distributions of Bengal (medium-grain), Cypress, and Drew (long-grains) rice varieties. Rice was harvested at various stages of maturity from Stuttgart and Keiser, Arkansas during the autumns of 1998, 1999, and 2000. Brown rice kernel dimensions decreased with harvest moisture content [HMC (Moisture contents are expressed on a wet basis)] below 24% HMC. Kernel dimensional distributions were usually single-modal and near normal. Brown rice dimensional variability, expressed by kernel dimensional standard deviation (SD), was significantly affected by HMC and location. Kernel dimensional SD generally was linearly and directly related to HMC. Among kernel dimensions, thickness had the greatest shrinkage with decreasing HMC, followed by length and then width. Among varieties, Bengal had the greatest kernel shrinkage, followed by Drew, and then Cypress.