Role of phosphatase-producing fungi on the growth and nutrition of clusterbean (Cyamopsis tetragonoloba (L.) Taub.)

The efficiency of different phosphatase-producing fungi (PPF) in arid soils (loamy sand) was studied in pot experiments in order to evaluate the effect of these fungi on the enhancement of rhizosphere enzyme activities, the uptake of different nutrients, dry matter production and grain yield of the clusterbean. A significant increase in phosphatase (acid and alkaline), dehydrogenase and nitrogenase activities was observed. Nodulation and nitrogenase activity were most affected upon inoculation. Inoculation significantly improved the dry matter production, grain yield, number and dry weight of nodules and decreased shoot: root ratio. In general, there was a significant enhancement in the concentration of N, P, Ca, Mg, Fe and Zn while no effect on Mn with the inoculation of any PPF on clusterbean. A significant improvement in K concentration due to inoculation of Aspergillus fumigatus and Cu concentration with the inoculation of Aspergillus rugulosus and Aspergillus terreus was noted. Aspergillus rugulosus was found to be the best amongst PPF tested followed by Aspergillus fumigatus. The experiment confirmed that PPF have a significant effect on growth and nutrient uptake in the clusterbean and indicated the importance of these fungi on clusterbean production in an arid soil.