In vitro evaluation of the chemical fungicides against Fusarium oxysporum f. sp. lycopersici causal organism of fusarium wilt of tomato

Tomato is the third important vegetable crop grown in India, after potato and onion with an area of 0.78 M ha and production and productivity of 19,759 Mt and 25.04 Mt ha-1 respectively. Tomato crop is very often affected by several diseases incited by pathogens such as fungi, bacteria, viruses and nematodes. Among all the fungal diseases that infect tomato, Fusarium wilt of tomato caused by Fusarium oxysporum f. sp. lycopersici (Fol), is one of the most serious and destructive diseases across the world causing severe economic losses, wherever tomato is grown. Due to prolonged survival of Fol in the soil as saprophyte and overcoming the challenging conditions by producing resistant structures, it has become very difficult to manage the disease. The most feasible method for managing Fusarium wilt disease of tomato is by usage of effective fungicides. Ten fungicides viz., Copper oxychloride 50%WP, Mancozeb 75% WP, Carbendazim 12% + Mancozeb 63% WP, Metalaxyl 4% + Mancozeb 64% WP, Hexaconzole 5% + Captan 70% WP, Thiophanate Methyl 70% WP, Thiophanate Methyl 45% + Pyraclostrobin 5% FS, Tebuconazole 250 E.C, Tebuconazole 50% + Trifloxystrobin 25% WP and Azoxystrobin 23% SC were evaluated against Fol under in vitro conditions at three concentrations i.e. 500, 1000 and 1500 ppm. Three replications were maintained for each treatment with control. Tebuconazole 50% + Trifloxystrobin 25% WP was found to be the most effective fungicide followed by Tebuconazole 250 E.C with high fungitoxicity against Fol. Azoxystrobin 23% SC was the least effective. The results of this present investigation will be helpful for future research on fungicide management for Fusarium wilt of tomato.