BIOEFFICACY OF MICROBIAL ANTAGONISTS AGAINST MACROPHOMINA PHASEOLINA ON SUNFLOWER

Seed treatment with biological control agents were found successful in prevention of fungal diseases of crop plants. In the present study, efficacy of microbial antagonists viz., Aspergillus flavus Link, Paecilomyces variotii Bainier, Trichoderma viride Pers., Rhizobium meliloti Dangeard and Bacillus subtilis Ferdinand Cohn was evaluated for their effect on plant growth promotion and against Macrophomina phaseolina (Tassi) Goid., the cause of root rot of sunflower (Helianthus annus L.). In dual culture assays, all antagonists inhibited the growth of M. phaseolina. Rhizobium meliloti and Bacillus subtilis showed maximum inhibition in the growth of M. phaseolina. Seed treatments with tested antagonists in blotting paper, test tube and pot experiments, did not show any detrimental effect on germination of sunflower seeds. On the other hand, in all the experiments seeds coating with antagonists proved effective in protecting sunflower seeds from root rot and significantly increased in root length and vigor index.