CUMULATIVE EFFECT OF RHIZOBIUM AND PHOSPHATE SOLUBILIZING BACTERIA ON YIELD, NUTRIENT UPTAKE AND GROWTH PARAMETERS IN CHICKPEA UNDER RAINFED CONDITIONS

Abstract

Nitrogen and phosphorus are the plant nutrients that play important role in crop growth and development. Inoculation with nitrogen fixers or phosphate solubilizing bacteria (PSB) may support the field crops in improvement of yield and quality. Nitrogen fixers not only provide N to plants but also improve the fertility status of soil. Similarly PSB can play important role in supplying phosphorus in an environmental friendly and sustainable manner. Chickpea is an important legume crop of Pakistan mainly grown in rainfed area. So, co-inoculation of rhizobium and phosphate solubilizing bacteria was studied to enhance the yield and nodulation of chickpea under rainfed conditions. The rhizobiums were isolated from the nodules of chickpea crop grown at rainfed area and PSB from the rhizosphere soil of rainfed chickpea crop. These isolates were screened for growth promotion of chickpea seedling under axenic conditions. All the isolates were found effective in improving the chickpea seedling growth with variable potential. The combination of three best rhizobium and three best PSB isolates were also screened for three best findings. Then these treatments were evaluated in pot and field studies under rainfed conditions for their effect on chickpea crop. Normal agronomic practices were followed till crop maturity. The inoculation and co- inoculation significantly boosted the grain yield, nodulation and growth parameters over the control. The yield increase was observed 35% for pot trial and 41% and 34% respectively for two years field experiments. The NP contents and uptake was also noted in increasing trend by the inoculation. The study revealed that yield and nodulation of chickpea was significantly improved over control with the sole inoculation of rhizobium and PSB strains, but co- inoculation reflected the more increase in growth and nodulation compared with single inoculation.