In vitro evaluation of fungicides against Bipolaris sorokiniana (Sacc.) Shoem

Spot blotch caused by Bipolaris sorokiniana is major threat for wheat cultivation due to continuous rise in temperature during the wheat growing season and high humidity coupled with winter rains, spot blotch is getting favourable conditions to develop aggressively and cause damage to wheat crop at larger scale by affecting significant yield loss up to 18-50 per cent under favourable conditions. Looking into significance of disease various non- systemic, systemic and combi product fungicides were evaluated in vitro conditions at three different concentrations for their efficacy against Bipolaris sorokiniana by following poisoned food technique. Results revealed that among non-systemic fungicides, irrespective of concentrations tested, the treatment involving captan 50% WP recorded maximum mean per cent mycelial inhibition (85.30%) and least mean per cent mycelial inhibition was recorded in chlorothalonil 75% WP (50.61%). Among the systemic fungicides, combi product fungicides tested, cent per cent inhibition was noticed in treatments involving hexaconazole 5% EC, propiconazole 25% EC and tebuconazole 250% EC, hexaconazole 5% + captan 70% WP, tebuconazole 50% + trifloxistrobin 25% WG and carboxin 37.5% + thiram 37.5% WP. Among the systemic fungicides least inhibition was noticed in thiophanate methyl 70% WP at all three concentrations followed by difenconazole 25% EC while among combi product fungicides tested,, carbendazim 12% + mancozeb 63% WP (62.22%) recorded least inhibition which was followed by fenamidone 10% + mancozeb 50% WG (77.40%).