In-vitro Efficacy of Fungicides against Colletotrichum truncatum Causing Anthracnose of Soybean

The study assessed the effectiveness of various single and combination fungicides against C. truncatum, the pathogen responsible for soybean anthracnose, using the poisoned food technique under laboratory conditions. In total a set of twelve fungicides comprising six single-molecule formulations and six combinations were evaluated at concentrations of 100, 250 and 500 ppm. Results showed significant differences in inhibition of test pathogen among different treatments. Among the single fungicides, carbendazim (50 WP) and tebuconazole (25.9% EC) achieved complete mycelial growth inhibition (100%) at 500 ppm. The mixture of carbendazim (25%) + mancozeb (50% WS) proved most effective overall, fully suppressing fungal growth at both 250 and 500 ppm. Strobilurin-based combinations like metiram + pyraclostrobin and penflufen + trifloxystrobin also demonstrated strong inhibition rates (>80%) at higher doses, whereas carboxin + thiram was the least effective, showing only 49.59% inhibition at 100 ppm. Overall, antifungal activity increased with concentration, with carbendazim + mancozeb standing out as a promising candidate for integrated management strategies, meriting further validation under field conditions. In this way, carbendazim (50 WP), tebuconazole (25.9% EC) or carbendazim (25%) + mancozeb (50% WS) could be identified as potential fungicides for integrated management of anthracnose of soybean.