In vitro evaluation of the chemical fungicides against the fungus Botrytis ricini

Castor (Ricinus communis L.) is an important non-edible oilseed crop which experienced serious declines in area under cultivation in Telangana state due to yield losses caused by gray mold pathogen Botryotinia ricini. B. ricini fungus were isolated from infected castor plants in ICAR-IIOR, Hyderabad and maintained in oat meal gar medium. Use of chemical fungicides is an important tool the management of gray mold disease in castor. Five systemic fungicides, Bavistin (Carbendazim), Score (Difenoconazole), Amistar (Azoxystrobin), Ergon (Kresoxim methy) and three combination formulation fungicides such as Merivon (Fluxapyroxad + Pyraclostrobin), Cabrio Top (Pyraclostrobin + Metiram) and Sectin (Fenamidone + Mancozeb) were evaluated for in vitro efficacy at concentrations of 100, 250, 500, 750 and 1000 ppm against gray mold pathogen. The poisoned food technique was used and radial mycelial growths were measured seven day after inoculation. Bavistin was found to be the most effective fungicide followed by Merivon have shown high fungitoxicity against B. ricini. Amistar were the least effective. The results of this present investigation will be helpful for future research on botrytis fungicide management and for castor growers in controlling gray mold disease of castor.