Synchronization of Flowering in Rice

Abstract

Flowering synchronization is prerequisite for producing hybrid seed successfully on a commercial scale. Seeding interval should be determined for achieving synchronized flowering. A field experiment for synchronization studies on flowering of 8 cultivars, 6 landraces and three cytoplasmic male sterile (CMS) lines of rice (Oryza sativa L.) was conducted during the wet season of 1999 at IAAS, Rampur. Flowering period was determined by growth duration and leaf number methods. The flowering period ranged from 80 to 104 days and leaf number from 10.24 to 14.7. Long duration cultivars had more leaf number. There was positive relationship between days to 50% flowering and leaf number. The leaf number and growth duration in most of the cultivars and landraces were higher than those of CMS lines. Leaf number differences between CMS lines and cultivars/landraces is narrow compared to the growth period differences thereby indicating the ease with which proper synchronization can be obtained in seed production plots. This suggests that the leaf number method will be more appropriate to calculate the seeding interval.

J. Inst. Agric. Anim. Sci. 23:89-92