Effect of Different Nitrogen Application Amount on the Net Increment of Fresh Dry Weight in Hybrid Rape

Objective]The aim of the research was to provide reference for reasonable application of nitrogen fertilizer for high yield cultivation of hybrid rape cultivar Youyan 9 and Youyan 10.Method] The net increment changes of individual plant fresh weight and dry matter weight of Youyan 9 and Youyan 10 with different nitrogen application treatments were studied.Result]The differences among average fresh weight increments of individual plant and average dry matter weight increment of individual plant with different treatments reached 0.01 extremely significant level. Fresh weight increment and dry matter weight net increment of individual plant declined gradually with the increase of nitrogen application. In growth course,fresh weight net increment of individual plant increased firstly then decreased and the maximum was in beginning flowering stage,besides that dry matter net increment increased gradually and the maximum was in mature period.The correlations among fresh net increment,dry matter weight net increment and yield net increment were positive or extremely positive.Conclusion]Under experimental condition,when nitrogen application was 225 kg/hm2,hybrid rape Yanyou 9 and Yanyou 10 with low erucic,low glucosinolate could obtain high yield.