Evaluation of new molecules of fungicides against Colletotrichum truncatum causing pod blight of soybean

Abstract

Pod blight of soybean caused by Colletotrichum truncatum, is a destructive disease resulting in severe yield and quality losses under warm and humid conditions. The present investigation was conducted to evaluate systemic, non-systemic and combi fungicides against C. truncatum under in vitro conditions using the poisoned food technique. Significant variation was observed among fungicide groups. Among non-systemic fungicides, Mancozeb 75% WP recorded the highest mycelial growth inhibition, followed by Chlorothalonil and Propineb. Systemic fungicides of the triazole group, particularly Tebuconazole 25.9% EC, Propiconazole 25% EC and Difenconazole 25% EC completely inhibited the mycelial growth of the pathogen at higher concentrations. Combi-products proved most effective overall with Tebuconazole 50%+ Trifloxystrobin 25% WG achieving near-complete inhibition, followed by Azoxystrobin+ Difenconazole and Pyraclostrobin+ Epoxiconazole. The results suggest that triazole-based systemic fungicides and strobilurin-triazole combinations are highly effective and can be integrated in pod blight management strategies.