Growth and grain yield of rice varietyJaya at different levels and timings of nitrogen application under two systems of water management

Studies on growth and grain yield of rice var:Jaya as influenced by graded levels of N and time of N application under continuous shallow submergence and/or cyclic submergence, have shown that the growth and dry matter production after flowering and consequently the grain yield of rice was significantly more under continuous shallow submergence than under cyclic submergence. The optimum dose of N for rice var:Jaya under conditions of these experiments was around 140 kg/ha. Panicle production and grain number per panicle increased significantly upto 150 kg N/ha, while there was a decline in panicle weight beyond 100 kg N/ha. Excessive N application beyond 150 kg/ha also resulted in more of spikelet sterility. The results indicate that under cyclic submergence, a minimum of three split applications of N are necessary, although the effect of two or three split applications were at par, under continuous shallow submergence.