Studies on grain filling and grain growth rates of different rice varieties in relation to chlorophyll content

Studies made with Rasi, Jaya, Jayanthi and Phalguna on gram filling pattern revealed that the partially filled grains appeared in declining order with the initiation of grain filling and the number of grains increased linearly with time. However, the absolute grain filling showed steadiness which gradually increased and tapered off. The growth rate among the varieties indicated different peaks like Jayanthi and Phalguna at 15 days, Jaya at 15–25 days and Rasi around 25 days. The chlorophyll content was maximum around mid tillering and declined gradually towards panicle initiation and very low at maturity. The amount of chlorophyll was more in leaves followed by stems and least in the panicles in all the varieties. Phalguna recorded highest chlorophyll content and Jayanthi lowest values exhibiting faster and slower grain filling patterns respectively.