The characteristics of the rice seed, either for planting or milling, are strongly influenced by
cultivar and harvesting time. Aiming to determine the proper harvesting interval for the irrigated ?IAC-238?
and ?IAC-242? rice cultivars, seeds produced in the 1988/1989 and 1992/1993 crop years, were harvested at
15, 22, 29, 36, 43 and 50 days after flowering and evaluated as to moisture content at harvest, dry matter,
kilograms per hectoliter, head rice yield, chalkiness, yield, germination, dormancy and storability during 18
months. The best harvesting interval for both cultivars was between 36 and 50 days after flowering, when
seeds presented superior indices of quality, yield and storability, with moisture content, just after harvest,
ranging from 18,3 to 26,2%. Until four months of storage, seeds of both cultivars exhibited strong dormancy,
which decreased to low levels at six months and became practically absent from eight months on.