In vitro exploration of bioagents and fungicides against Sclerotium rolfsii Sacc. causal agent of horse gram collar rot

Abstract

Collar rot caused by Sclerotium rolfsii Sacc., is a very destructive disease that affects the production of horse gram significantly in the Konkan region of Maharashtra causing 25-30% losses. This study evaluated the efficacy of seven fungicides viz., Mancozeb 75% WP, Propiconazole 25% EC, Captan 50% WP, Tebuconazole 25.9% EC, Carbendazim 50% WP, Carboxin 37.5% + Thiram 37.5% WS (75% WS) and Carbendazim 12% + Mancozeb 63% (75% WP) and six bioagents viz., Trichoderma viride, T. harzianum, T. koningii, T. longibrachiatum, Bacillus subtilis and Pseudomonas fluorescens against S. rolfsii. Among the seven fungicides tested Propiconazole 25% EC, Tebuconazole 25.9% EC, Carboxin 37.5% + Thiram 37.5% WS (75% WS) each @ 0.1% concentration and Carbendazim 12% + Mancozeb 63% (75% WP) @ 0.2% concentration were found significantly effective in inhibiting the mycelial growth of S. rolfsii with 100% inhibition over control. Among the bioagents tested, T. longibrachiatum showed the highest percent inhibition of 44.67% with lowest mycelial growth (49.80 mm) of Sclerotium rolfsii.