Evaluation of Fungicides against Ustilaginoidea virens Pathogen Causing False Smut Disease of Rice

Abstract

False smut of rice caused by Ustilaginoidea virens is most destructive disease of rice causing 5-85 per cent yield losses in India. In the present investigations, six novel fungicides viz., Flusilazole 25% + Carbendazim 12.5% SE, Trifloxystrobin 25% + Tebuconazole 50% WG, Carbendazim 12% + Mancozeb 63% WP, Azoxystrobin 18.2% + Difenoconazole 11.4% SC, Azoxystrobin 11% + Tebuconazole 18.3% W/W and Copper hydroxide 50% WP were tested in vitro against the false smut of rice pathogen Ustilaginoidea virens. The maximum mycelial growth was observed in case of Copper hydroxide 50% WP (21.20 mm) as compare to control (60.70 mm) after 21 days incubation. All the fungicides significantly inhibited the fungal mycelial growth in all concentrations (10, 25, 50, 75 and 100 ppm). Among six fungicides evaluated under in vitro condition Trifloxystrobin 25% + Tebuconazole 50% WG showed highest mycelial growth inhibition (86.66%) at 100 ppm followed by Flusilazole 25% + Carbendazim 12.5% SE (78.91%) whereas least mycelial inhibition was recorded in case of Copper hydroxide 50% WP (65.07%) after 21 days of incubation.