Effects of Different Planting Date,Density and Nitrogen Application Amount on Yield of Rapeseed

The effect of four sowing dates,four plant densities and four nitrogen application amounts on rapeseed yield by split-split plot design.The results indicated that sowing date,plant density and nitrogen application amount affected rapeseed yield very significantly.The interaction of plant density and nitrogen application amount affected rapeseed yield very significantly.The interaction of sowing date and nitrogen application amount affected rapeseed yield very significantly,too.The suitable sowing date was the end of September,the planting density was 375,000~450,000 plant/hm2 and Urea application amount was 375~450 kg/hm2,the highest yield was obtained in Wanyou 29.