Effect of Mesorhizobium, plant growth promoting rhizobacteria and phosphorus on plant biometery and growth indices of desi chickpea (Cicer arietinum L.)

Abstract

The field experiment was conducted during 2015-16 to study the effect of biofetilizer inoculation [control, Mesorhizobium only, Mesorhizobium + RB-1 (Pseudomonas argentinensis) and Mesorhizobium + RB-2 (Bacillus aryabhattai)] and four levels of phosphorus (0, 15, 20 and 25 kg P2O5 ha-1) on chickpea growth. RB-1 and RB-2 were the plant growth promoting rhizobacteria (PGPR). Biofertilizers could play a crucial role in reducing the dependence on chemical fertilizers by fixing the atmospheric nitrogen for crop and/or by increasing the availability of phosphorus and phytohormones to the crop. The 16 treatment combinations were laid out in Factorial Randomized Complete Block Design and replicated three times. In biofertilizer treatments, Mesorhizobium + RB-1 proved superior over control and sole inoculation of Mesorhizobium and at par with Mesorhizobium + RB-2 with respect to plant height (cm), number of branches (plant-1), shoot and root dry matter (kg ha-1) which were recorded at 30, 60 90, 120 days after sowing (DAS) and at harvest. Application of 25 kg P2O5 ha-1 gave the highest values of all the growth at-tributes viz. plant height (60 cm), number of primary (5.3) and secondary (27.2) branches per plant, shoot dry matter (4000 kg ha-1) and root dry matter (354 kg ha-1) which were significantly higher than that of 0 and 15 kg P2O5 ha-1 and at par with 20 kg P2O5 ha-1. Similar results were observed in case of crop growth rate (CGR) whereas relative growth rate (RGR) was not influenced significantly by various biofertilizer and phosphorus treatments. The dual inoc-ulation with PGPR strains along with phosphorus application have a supplementary effect on the growth of chickpea.