Published online by Cambridge University Press: 27 March 2009
Nitrogen fixing, free-living, organisms like Azotobacter and Azospirillum are known to increase the nodulation and efficiency oiRhizobium (Krasilinikov & Korenyakov, 1944). The beneficial effect of incorporation of Azotobacter with Rhizobium may be due to the production of auxins (Vancura & Macura, 1960) and prolonged survival of Rhizobium in the presence of a large amount of polysaccharide gums (Krasilinikov & Korenyakov, 1944). In green gram (Vigna radiata L. Wilczek), because of high temperature and unavoidable soil moisture stress during hot and dry summer months (April-June), survival of the seed-inoculated Rhizobium is very poor (Lai, Dubey & Chandra, 1983). In the present study attempts were made to improve the efficiency cf Rhizobium as an inoculant by the use of Azotobacter chroococcum and Azospirillum brasilense.