Evaluation of Trichoderma Isolates for Management of Soybean Anthracnose Caused by Colletotrichum truncatum

Abstract

Soybean anthracnose, caused by Colletotrichum truncatum, is a major constraint to soybean productivity worldwide. The present study evaluated the antagonistic potential of eight Trichoderma isolates against C. truncatum under both In-vitro and in-vivo conditions to identify effective biocontrol agents for sustainable disease management. In-vitro screening, conducted using the dual culture technique on Potato Dextrose Agar (PDA) in a Completely Randomized Design (CRD) with nine treatments (including one untreated control), revealed significant inhibition of pathogen growth by all isolates. Among them, T. reesei-1 exhibited the highest mycelial inhibition (55.56%), followed by T. harzianum-2 (54.70%), T. harzianum-1 (51.71%), and T. reesei-3 (49.57%). In-vivo evaluation under greenhouse conditions showed a marked reduction in anthracnose incidence, with T. reesei-1 recording the lowest disease incidence (6.25%) compared to 76.25% in the pathogen control. The strong antagonistic effect of these isolates may be attributed to the production of antifungal metabolites and efficient root colonization. Overall, the study highlights T. reesei-1 and T. harzianum-1 as promising bioagents for the eco-friendly and sustainable management of soybean anthracnose.