Seed dormancy is a genetically inherited trait whose intensity is modified by the environment during seed
development and maturation. In order to study the effect of harvest time on the seed quality and optimum
time of sowing to obtain good quality seeds, freshly threshed seeds of ten diverse rice genotypes harvested
from six environments were evaluated for seed dormancy and seedling vigour index as a measure of seed
quality. There were significant differences in germination in different genotypes in all the six
environments as well as days after harvest. The germination percentage was initially low and gradually
increased with increasing in days after harvest (0. 15, 30 and 45th day after harvest). Out of these six
genotypes viz., IET 8116, KMP 101, IR 30864, KRH-1, IR-64 and MTU 1001 were found dormant,
immediately after harvest. The studies indicated that sowing in the first (June 2nd fortnight) and second
environment (July 1st fortnight) were resulted in production of non-dormant seeds. Whereas all the six
environments were favorable to take up seed production of new promising rice genotype KMP 101.