Evaluation of Antagonist Effect of Trichoderma species against Vascular Wilt Causing Fusarium solani on Solanum melongena

Abstract

Brinjal (Solanum melongena L.) is an economically important vegetable crop that is susceptible to a range of soil-borne fungal diseases, including vascular wilt caused by Fusarium solani. The present study investigated the in vitro antagonistic potential of Trichoderma isolates against F. solani and assessed their relative efficacy in suppressing the mycelial growth of the pathogen. Ten Trichoderma isolates were recovered from rhizospheric soil associated with healthy brinjal plants collected from different locations across the Bundelkhand region. The isolates were maintained in pure culture and assessed against F. solani using a dual-culture assay on potato dextrose agar. Mycelial discs of the pathogen and each antagonist were placed on opposite sides of Petri plates, which were incubated at 26°C for 9 days. Pathogen growth was assessed on the third, sixth, and ninth days, and percentage inhibition was determined relative to the control. All ten Trichoderma isolates exhibited antagonistic activity against F. solani, with differences in inhibitory performance among isolates. TCX5, identified as Trichoderma harzianum, showed the highest antagonistic activity, whereas TCX3 showed the lowest inhibition among the tested isolates. These findings demonstrate isolate-level variation in the antagonistic potential of Trichoderma against F. solani under laboratory conditions. The promising isolates require further molecular characterisation and validation under greenhouse and field conditions before their practical use in brinjal wilt management can be recommended.