In vitro evaluation of fungicides, botanicals and bioagents against Rhizoctonia solani causing sheathblight of rice and their integration for effective management of the disease under field conditions

摘要

Five fungicides viz., carbendazim 50 WP, hexaconazole 5 EC, propiconazole 25 EC, Saaf 75 WP and vitavax 75 WP were evaluated @ 10,25,50,100,200 and 500 ppm each. Nine botanicals viz., Bhang (Cannabis sativa), Bael (Aegle marmelos), Eucalyptus (Eucalyptus citridora), curry leaves (Murraya koenghii), congress grass (Parthenium hysterophorus), paanch phooli (Lantana camara), tulsi (Ocimum sanctum), drek (Melia azedirach) and onion (Allium cepa), each @ 5,10,15 and 20% and twelve isolates of residentialbioagents viz., four isolates each of Trichoderma viride, Trichoderma harzianum and Pseudomonas fluorescens were evaluated in vitro against Rhizoctonia solani, an incitant of sheath blight in rice following poisoned food technique. All the test fungicides, botanicals/plant leaf extracts and bioagents showed fungistatic action and significantly inhibited mycelial growth of the test pathogen over untreated control. Among the fungicides Saaf (carbendazim 12% + mancozeb 63%) was the most effective fungicidewhich registered cent per cent inhibition even at 10 ppm followed by carbendazim (98.9%), Vitavax (98.2%), propiconazole (74.8%) and hexaconazole (72.9%). Among botanicals drek extract was most effective inhibiting 46.5% per cent of the mycelial growthof R. solani followed by bhang (29.7%), onion (25.4%), tulsi (23.9%), bael (20.6%), paanch phooli (17.9%), curry leaves (14.1%), congress grass (13.4%) and eucalyptus (10.4%) and among bioagents isolates of T. viride were more effective than isolates ofT. harzianum and P. fluorescens.