G. Renuka, M.S. Rao, V. Praveen Kumar, M. Ramesh and S. Ram Reddy
Abstract
Investigations were carried out to determine the effect of some agrochemicals (pesticides, fertilizers and weedicides), manures (FYM, neemcake), heavy metals and environmental pollutants (sewage) on mycorrhizal colonization and seedling growth of Acacia melanoxylon. Treatment with captan (fungicide), sevin (insecticide) and 2,4-D (weedicide) showed that mycorrhizal infection was enhanced in all the treatments. However, the enhancement effect varied with the type of pesticide. In between the urea and superphosphate, the latter enhanced the mycorrhizal colonization and seedling growth more than the urea. Treatment of nursery beds with neemcake and farm yard manure significantly enhanced the mycorrhizal colonization, nodulation, biomass and phosphorous uptake. Sewage treatment has shown inhibitory effect on mycorrhizal infection, nodulation and growth of seedlings. Application of heavy metal has shown adverse effect on mycoorhizal colonization. Maximum depressing effect was evident in cobalt and lead and least inhibitory effect was in zinc and manganese.