Influence of Grain Moisture at Harvest on Seed Yield, Quality, and Seedling Vigor of Rice1

Abstract

Rice (Oryza sativa L.), Cultivar Caloro, was harvested at 13 levels of moisture content in the grain beginning at 43% and ending at 13%. Seed yields increased rapidly as grain moisture decreased from 43 to 31%. They increased slowly between 31 and 19%, but remained constant thereafter. Weight per seed and liter weight followed the same trend as seed yields. Germination percentage increased steadily as grain moisture decreased. Speed of emergence of seedlings through 10 cm of water was faster when grain was harvested below 20% moisture. Shoot length of seedlings grown on blotters held at a 67° angle in a germinator indicated earlier and faster growth as grain moisture decreased to 13%. Resistance of seedlings to the water mold (Achlya klebsiana Pieters) was optimum when grain was harvested at 13% moisture.