In vitro Bio-Efficacy of Bio-Agents Against Sclerotium rolfsii Sacc. Causing Stem Rot Disease in Groundnut

Soil-borne plant pathogenic fungi cause heavy crop losses all over the world. With variable climate from region to region, most crops grown in India are susceptible to diseases caused by soil-borne fungal pathogens. Among tropical and subtropical land crops, groundnut (Arachis hypogaea L.) is an important oil seed crop, providing vegetable oil as human food and oil cake meal as animal poultry feed. A large number of diseases attack groundnut plants in India; of these, stem rot (collar rot) caused by Sclerotium rolfsii is the most common disease. Pathogenecity was proved by Koch's postulates. Biological management of the disease through antagonists is an eco-friendly approach apart from better alternative to the use of chemicals. In the present study, the nine antagonistic microorganisms were evaluated by dual culture technique for their antagonistic effect against S. rolfsii under in-vitro conditions. Maximum inhibition of mycelial growth (75.00%) was noticed in Trichoderma asperullum (Bacteriology lab UAS, GKVK isolate) and two isolates were showed least inhibition in T. viride (NBAII) and T. harzianum-(Th6) (51.67%). The results indicated that the application of these native micro-organisms successfully decreases the stem rot incidence and also increases the growth of the groundnut plants.