Effect of seed inoculation with Azotobacter and Azospirillum and different nitrogen levels on yield and yield components of canola (Brassica napus L.) , Mahboobeh Naderifar1*, Jahanfar Daneshian2

In order to investigate the effect of different levels of nitrogen and bio-fertilizers on yield of canola plants in Qazvin, Iran, a split-plot design was conducted on the 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 (no inoculation, Azotobacter, Azospirillum and a combination of Azotobacter and Azospirillum). Results showed that nitrogen treatment had a significant effect on yield and yield components. Significant increase was observed in all characters with applying bio-fertilizers. Interaction of effect of nitrogen and bio-fertilizers treatments on seed yield showed when no nitrogen fertilizer was used, the highest seed yield was obtained from the combined use of bio-fertilizers. But with application of 150 N (kg ha-1), the highest seed yield was obtained when no bio-fertilizers were applied. The oil yield was also influenced by experimental treatments so that the highest oil yield was obtained from 75 and 150 kg ha-1 N treatments. The combined use of bio-fertilizers also was statistically superior to other treatments. According to findings  of the present  study, it can be concluded that  farmers  can obtain  the same  canola  yield  if they apply  half  the conventional allocation of nitrogen with bio-fertilizers.