Abstract:
Rice (Oryza sativa L.) is one of the most important cereal crops in the world. For enhancing
productivity, quality seeds play a major role and seed hardening is used as cost effective
and easy method to enhance seedling vigor in rice. Seed and seedling vigor lead to perfect
field establishment and better crop performance under adverse conditions. Present study
was conducted to examine re-germination and seedling vigor of rice subjected to different
period of water stress on germinated seeds. Three rice varieties namely AT 353, AT354, and
AT362 were used. Re-germination ability was examined up to 20 days water stress period
and 91% germination was observed even after 20 day water stress. Rice as a determinant
crop, long period of water stresses to germinated seeds reduce the length of vegitative
period and subsequently it should have an effect on final yield. Therefore, seedling vigor
was examined in seed samples undergone up to 10 day water stress period. Seven and 20
days after re-germination, root and shoot lengths were recorded to calculate vigor index
of seedlings. Significant increment of vigour indexes were observed in seedlings originated
from treated seeds. Seven days after re-germination highest root length (3.56cm) and
vigor index (7.43) were observed in seedlings which were originated from seeds with four
days water stress period. However, in 20 day old seedlings, highest root length (10.94cm)
and seedling vigor (24.89) were recorded after eight day water stress period. These results
revealed that seedling vigor of rice can enhance by giving water stress on germinated seeds
without an effect on re- germination ability.
