Effect of different nitrogen and biofertilizers effect on growth and yield ofBrassica napus L.

ABSTRACT: Nitrogen different levels and biofertilizers effects were studied on growth and yield of canola in Qazvin province. An experiment was conducted in a split-plot design as base of randomized complete block design with four replications. Treatments included 3 levels of nitrogen (0, 75 and 150 kg ha-1) and bio-fertilizers on four levels (not inoculation,Azotobacter,Azospirillumandwithinoculation combined).The results showed that nitrogen had significant effect on the seed number per silques, number of silques per plant, seed yield , 1000 seedweight, seed yield and Plant height. So that with the increased use of nitrogen fertilizer, all of these traits increased.and the combined use of was also increased on Seed yield. interactionof nitrogen and biofertilizeraffected on seed yield, significantly. Using of nitrogen fertilizer in amount of 2195 produce the highest seed yield when seeds were inoculated by biofertilizers. 150 N(kg ha-1) and non inculation produced the highest seed yield. The combined use of biofertilizers also was statistically superior to other treatments.However,the highest yield was got from 150 but itseems using of 75 N(kg ha-1) and inoculation of Azospirillum and Azotobacterproduced suitable yield (20% loss).