The Study of different base nitrogen levels on yield components of Rapeseed (Brassica napus L.) Caltivars

In order to study the effect of base nitrogen levels on yield components of Rapeseed cultiva experiment carried out in factorial design on the base of randomized complete blocks with 4 replications from 2003 to 2005 that base nitrogen fertilizer was at 3 levels (0, 50 and 100 Kg/ha pure nitrogen) and Rapeseed cultivars at 6 levels Talaye, SLM046, Okapi, Regent*Cobra, Licord and Orient considered. Multiple variance analysis for 2 years showed that the effect of base nitrogen, cultivars and interaction effect between base nitrogen and cultivars on pods per plant, seed number per pod and 1000 seed weight had significant effect and the effect of base nitrogen on seed number per pod did not show any difference at 5% level. The compairing results of two years examination showed that after base nitrogen increased to 100Kh/ha, the average amount of pod number per each plant increased to 109.9 and cultivar regent*cobra with 132.9(in average 3 levels of Base nitrogen) and application of 100 Kg/ha base nitrogen in Regent*cobra with 176.3 showed maximum amount of pod number per plant. Multiple Mean comparison of interaction effect between base nitrogen levels and cultivars showed that application of 100Kg/ha base nitrogen in Okapi with 69.27 gained maximum seed per each pod.Maximum amounts of 1000 seed weight conducted in application of 100 Kg/ha base nitrogen in Regent*Cobra and non application of nitrogen with 3.91 g.