Effect of Planting Dates on Yield and Quality of Japonica Rice Seed

Abstract

The experiment was conducted to determine the suitable planting dates for japonica rice in the lower northern region at Phitsanulok rice Research Center. Two japonica rice varieties, Akitakomachi and Koshihikari were planted at the early and the middle of November, Decomber 1992, and January 1993. Akitakomachi, planted from early to middle November, gave the highest yield, and the best seed quality measured as percentage of gemination, vigor and storability was obtained from the planting date of middle November. Koshihikari gave the gighest yield from middle November to early December, and the best seed quality from early December.