A pot culture experiment was conducted in the Department of Microbiology, Faculty of Agriculture at Annamalai nagar to study the effect of Glomus fasciculatum on the growth and yield of MCU-7 cotton as influenced by different levels of N and P viz., 25, 50, 75 and 100 per cent recommended dose (RD) with Arbuscular – Mycorrhizal Fungi (AMF) and 100 per cent N and P without AM fungi (control) were maintained. Among the different treatments, 75 per cent P with 100 per cent N+ AM fungi was observed with better yield and P up take in cotton and maximum mycorrhizal colonization and spore number were recorded at 50 per cent P and 100 per cent N RD + AM fungi followed by application of 50 per cent P with 100 per cent N RD+AM fungi. Hence, this study revealed that 25 per cent of phosphatic fertilizer could be saved by the inoculation of G. fasciculatum in cotton.
