Effects of Inoculation of Native Azotobacter on Yeild and Growth Indices of Wheat in Iran

Azotobacter is a plant growth promoting rhizobacterium that can stimulate the growth of plants by different mechanisms, including nitrogen fixation, production of phytohormones and ability of solubilizing phosphorous. In this research 10 isolates of Azotobacter chroococcum (selected form previous investigations) native to Iranian soils, were used for field experiments. The field experiments were conducted with ten bacterial inoculation treatments and control in randomized completed block design with three replications in some provences in Iran. The inoculums were prepared in powdery forms with perlite as carier. The inoculums were used as seed inoculation. Diverse results were observed s in different provinces. In Azerbaijan Sharghi, 9 isolates increased the total yield of wheat and one isolate (T7) increased significantly the straw and stubble compared to control. T3 and T4 increased significantly the thousands-seed weight over control. The results in Khorasan Razavi province revealed that T11 increased the height and yield of straw and stubble and T10 isolate increased significantly the nitrogen content in the flag leaf. In Fars province, T8 isolate had the highest mean on seed yield and shoot dry weight. There was not significant effect of inoculation on growth indices of wheat in Kordestan and Azerbaijan gharghi provinces.