Effect of Integrated Application of Azotobacter chroococcum and Azospirillum brasilense and Nitrogen Chemical Fertilizers on Qualitative and Quantitative of Durum Wheat

To study the effect of plant growth promoting bacteria (PGPR) and mineral nitrogen fertilizer on yield and yield components of three durum wheat cultivars, an experiment was conducted as a split factorial based on randomized complete block design with three replications in Dehloran Research Station in Ilam, Iran in 2011-2012 cropping season. Experimental factors consisted of durum wheat (Yavaroosm, Kharkheh and Simareh) was assigned to main plot and nitrogen fertilizers at 3 levels (40, 80 and 120 kg.ha-1) and bio-fertilizer (non-inoculation, inoculating with Azotobacter chroococcum, Azospirillum brasilense) to sub plot. Results of analysis of variance showed that among cultivars studied there were significantly differences at traits under study. Yavaroos had the highest plant height, 1000- grain weight, and biological yield. The highest plant height, 1000- grain weight, biological yield and protein content was obtained by application of 120 kg/ha nitrogen fertilizer, but there were not different effect between 80 and 120 kg/ha nitrogen fertilizer. Traits under study were affected by using bio-fertilizer. The highest plant height, number grain per spike, 1000- grain weight, grain yield were obtained from inoculation plants with bio-fertilizer. The effect of cultivar by nitrogen chemical fertilizer interaction had significant effect on plant height, number of grain per spike, 1000-grain weight, and spike per meter squared and grain yield. The highest grain yield was obtained from Yavaroos using 120 kg/ha and the lowest grain was observed from Simareh cultivar and 40 kg/ha. Interaction effect of cultivar and bio- fertilizer had significant effect on harvest index only. Nitrogen fertilizer by bio- fertilizer interaction had significant effect on only grain yield, spike/m-2 and grain yield. The highest grain yield was obtained from Yavaroos cultivar when it were inoculation with Azospirillum 120 kg/ha and the lowest grain yield observed Simareh cultivar when it was treated with 40 kg/ha