Investigate Panicle Structure in Rice by application nitrogen and phosphorus fertilizer

In order to investigate the effect of nitrogen and phosphorus fertilizer on panicle structure in rice cultivar(Oryza Sativa L), an experimental design in north of iran in 2011 cropping season. Nitrogen fertilizer at 50,100 and 150 kg/ha was main plot and phosphorus fertilizer at 4 level 0(control), 30, 60 and 90kg/ha as sub plot. Using randomized complete block desing(RCBD) with 3 replication. The results showed that panicle number, panicle lenght, primary branches, filled grain, 1000-garin weight , straw and grain yield increased significantly with nitrogen fertilizer,but the unfilled grain decrease by application nitrogen fertilizer. Interesting in comparison to 50 and 100 kg/ha level application of higher N-fertilizer 150 kg/ha showed a positive respond to application of high nitrogen for taroom hashemi cultivar. Effect of different application of P-fertilizer were significantly on panicle number, filled grain, unfilled grain,1000-garin weight , straw and grain yield. this parameter increase by application P-fertilizer, but the unfilled grain decrease by application phosphorus fertilizer. study of interaction effect of N and P- fertilizer was significant in panicle number and 1000-grain weight.