Efficacy of different fungicides against Rhizoctonia solani causing sheath blight of rice

Abstract

Sheath blight, caused by multinucleate Rhizoctonia solani Kuhn (teleomorph: Thanatephorus cucumeris Donk), a ubiquitous pathogen, is an important fungal disease of rice ranking only after blast and often rivaling it. The potential losses due to sheath blight alone in India has been up to 51.3%. In this study an attempt was made to investigate a new combination fungicide Flusilazole 12.5% + Carbendazim 25%SC (Lustre 37.5 SE) was found to be most effective in minimizing the severity of sheath blight with 31.34% and also showed less incidence (4.17%) of sheath blight at 80 DAT. Remaining other fungicides were significantly less effective than Flusilazole 12.5% + Carbendazim 25%SC but at par among themselves. The highest 1000 grain weight was noticed in treatment Kasugamycin 3%SL (35.67 g) followed by Flusilazole 12.5% + Carbendazim 25%SC (34.0 g), Hexaconazole 5%EC (33.67g) and Carbendazim 50%WP +Propiconazole 25% EC (30.00g). However, The highest number of healthy grain per 1000 grain were recorded in the treatment Kasugamycin 3%SL (848 grain/1000 grain) followed by Flusilazole 12.5% + Carbendazim 25%SC (836 grain/1000grain) and Propiconazole 25% EC (825 grain/1000 grain).The lowest average number of chaffy grain per 1000 grain was recorded in the treatment Hexaconazole 5%EC (87 grain/1000 grain) followed by Kasugamycin 3%SL (102 grains/1000grains) and Flusilazole 12.5% + Carbendazim 25%SC (107 grain/1000grain) whereas lowest number of discolored grain per 1000 grain was observed with the treatment, Kasugamycin 3%SL (51 grain/1000 grain) followed by Flusilazole 12.5% + Carbendazim 25%SC (58 grain/ 1000 grain) and Azoxystrobin 23%SC (75 grain/1000 grain) observed with control. Highest plant height with Carboxin 37.5% + Thiram 37.5% WP (66.85 cm), highest number of tillers per m2 recorded in treatment Hexaconazole 5%EC (217 tillers/m2), highest panicle length recorded the treatment Carbendazim 50%WP +Propiconazole 25% EC (27.80 cm) and number of seed per panicle were recorded in treatment Carboxin 37.5% + Thiram 37.5% WP (155 seed/ panicle). Highest biological yield was recorded with the application of Carboxin 37.5% + Thiram 37.5% WP (25.83 kg/plot). Highest grain yield recorded due to application of Azoxystrobin 23% SC (6.50 kg/plot) and straw yield recorded with Carboxin 37.5% + Thiram 37.5% WP (19.33 kg/plot) during both the years. Lowest AUDPC values were exhibited due to application of Flusilazole 12.5% + Carbendazim 25%SC (AUDPC 1523.70) followed byCarbendazim 50%WP +Propiconazole 25% EC (AUDPC of 2355.60) and Mancozeb 63% + Carbendazim 12%WP (AUDPC of 2375.70).