Interaction between Glomus geosporum, Azotobacter chroococcum, and Bacillus coagulans and their Influence on Growth and Nutrition of Melia azedarach L.

A green house nursery study was conducted to assess the interaction between arbuscular mycorrhizal fungus, a nitrogen fixing bacterium, Glomus geosporum, Azotobacter chroococcum, and a mycorrhiza helper bacterium (MHB), Bacillus coagulans, in soil and their consequent effect on growth and nutrition of Melia azedarach L. seedlings. Triple inoculation of G. geosporum, A. chroococcum, and B. coagulans resulted in maximum plant biomass, N, P, Zn, and Cu uptake, and biovolume and quality index of M. azedarach seedlings. It also increased the mycorrhizal root colonization and spore numbers in the root zone soil of the inoculated plants over uninoculated control plants. The enzyme activity, namely acid phosphatase and dehydrogenase, in the root zone soil was found high in the 3-combination treatments and low in the uninoculated control. Triple inoculation with G. geosporum + A. chroococcum + B. coagulans proved to be the best microbial consortium for inoculating M. azedarach at nursery level in order to get healthy and vigorously growing seedlings.