Abstract
A study was undertaken to determine the effect of VAM fungi on growth and nutrient uptake of clusterbean and to elucidate concurrent role of phosphatases in P uptake. Nodulation, N2‐ase activity, percent root infection by VAM fungi, and the number of VAM spores in the rhizosphere increased significantly upon inoculation. There was no change in the activity of acid phosphatase in the mycorrhizosphere, while alkaline phosphatase activity was enhanced, indicating that the enzyme increased the availability of P by the breakdown of organic phosphates. An improvement in dry matter production and grain yield of clusterbean upon inoculation with VAM fungi was evident. Inoculation did not influence the uptake of K and Fe but the concentration of P, Zn, Cu, and Mn in the mycorrhizal plants was increased.