In vitro evaluation of fungicides and bio-agents against Rhizoctonia solani causing sheath blight disease of rice

Abstract

Sheath blight of rice caused by Rhizoctonia solani is one of the threat limiting to rice cultivation in India. Considering economic importance of the crop as well as destructive nature of the disease, present in vitro studies were undertaken to evaluate the efficacy of seven fungicides and six bio-agents, to assess their potential against R. solani. Results indicated that at a lower concentration, mycelial growth inhibition was numerically highest and cent per cent (100%) with Hexaconazole 5% EC, Tebuconazole 50% + Trifloxystrobin 25% WG and Azoxystrobin 11% + Tebuconazole 18.3% SC. Whereas, at a higher concentration, mycelial growth inhibition was numerically highest and cent per cent (100%) with Hexaconazole 5% EC, Tebuconazole 50% + Trifloxystrobin 25% WG, Azoxystrobin 11% + Tebuconazole 18.3% SC and Azoxystrobin 23% SC. Among the six bio-agents tesed Trichoderma harzianum recorded significantly highest mycelial growth inhibition (63.89%) of the test pathogen, followed by Pseudomonas fluorescens (53.34%), T. longibrachiatum (34.45%), T. konigii (32.78%) and Bacillus subtilis (30.56%).