Suitable form and level of phosphorus for mass production of the VA mycorrhizal fungus Glomus fasciculatum

Abstract

Summary Three sources of phosphorus viz., bone meal (12 % P), Mussorie rock phosphate (18 % P) and super phosphate (16 % P), were tried at 0, 5, 10, 20, 40 and 80ppm P (by volume of the substrate) to select suitable form and level of P for mass production of Glomus fasciculatum inoculum using Chloris gayana (Rhodes grass) and perlite: soilrite (1:1 by volume) as host and substrate, respectively. Percentage root colonization, extramatrical chlamydospore number and inoculum potential were highest at 10ppm P applied as rock phosphate. Among the 3 forms, super phosphate reduced significantly all the mycorrhizal parameters. Plant P concentration increased with increasing levels of P applied to the substrate mix in all the 3 forms and the total P concentration of shoot and root was maximum in plants treated with super phosphate followed by bone meal and rock phosphate.