Microorganisms found associated with plants reside in rhizosphere, rhizoplane, phylloplane and inside plant tissues. These microbes play an important role in various stages of plant growth and development. They also find application as biocontrol agent against various pathogens of plants and can be used as an alternative to chemical fungicides. Grasses and their roots are major source for microbial interaction and get rejuvenated therefore the chances of colonization of microbe is high. In view of this, the present work has been carried out to study the antagonistic activity of fungal organisms associated with rhizosphere and rhizoplane regions of grass Cynodon dactylon from Northern Kerala parts of Western Ghats in different seasons against fungal diseases of Mahogany seedlings of Central Nurseries of Kerala in vitro. Rhizosphere and rhizoplane fungi included Aspergillus niger, Curvularia sp. Fusarium oxysporum, Fusarium sp. Mucor sp. Penicillium sp. Rhizopus sp. Trichoderma harzianum and NSF. Antagonistic activity was conducted against the fungal species associated with the root rot diseases of mahogany seedlings caused by Fusarium oxysporum and Fusarium monoliforme, damping off by Sclerotium rolfsii and foliar diseases caused by Colletotrichum gloeosporiodes, Alternaria alternata, Curvularia lunata,Cladosporium cladosporioides and Pestalotiopsis sp. Trichoderma harzianum was found to be effective controlling agent in vitro.
