Stimulatory effects of dual inoculation with phosphate solubilising microorganisms and arbuscular mycorrhizal fungus on chickpea

The stimulatory effect of rhizotrophic microorganisms on growth, yield and nutrient uptake of chickpea was determined in a pot experiment using sterilised soil deficient in available phosphorus (P). Plant vigour, yield and nutrient uptake were significantly enhanced following inoculation with Mesorhizobium ciceri and the phosphate solubilising bacterium Serratia (T1) or phosphate solubilising fungus Penicillium (WF6). Composite application of Mesorhizobium ciceri with Serratia and arbuscular mycorrhizal fungus Glomus fasciculatum had maximum positive effect on chickpea plants (0.68 and 2.21 g/plant at 50 and 90 days after sowing, respectively). Among all the treatments, the performance of M. ciceri with Serratia and G. fasciculatum and M. ciceri with Penicillium and G. fasciculatum was superior and increased the seed yield by 41 and 23%, respectively. The interactive effects were synergistically significant following inoculation of M. ciceri with Serratia and G. fasciculatum and Serratia with Penicillium and G. fasciculatum, which improved the photosynthetic pigment by 47 and 37%, respectively, relative to the control. Protein content in seeds varied between 18 and 24% in inoculated chickpea. Number of nodules formed per plant was higher at 90 days after sowing than 55 days after sowing. Phosphorus status of soil was improved by Serratia coinoculated with M. ciceri and G. fasciculatum but N content in general did not differ appreciably. At 90 days after sowing chickpea, there was an increase in (i) populations of phosphate solubilising microorganisms in some treatments, (ii) percentage root infection and (iii) spore density of the arbuscular mycorrhizal fungus in the soil.