Efficacy of Biocontrol and Antifungal Agents on Leaf Spot and Blight Pathogen Fusicladium pongamiae in Millettia pinnata: An In vitro Approach

Millettia pinnata is a valuable tree species, commonly planted for its economic and ecological contribution. Despite this, it is susceptible to a number of foliar diseases, of which leaf spot and blight, induced by Fusicladium pongamiae, are major hazards in nursery and plantation conditions. The current research was conducted to isolate, identify, and determine the pathogenicity of F. pongamiae, and to test the effectiveness of chosen biocontrol agents (Trichoderma viride and Pseudomonas fluorescens) and antifungal agents (Pongam oil and Carbendazim) under in vitro conditions. Infected leaf samples were obtained and the pathogen was purified on Potato Dextrose Agar (PDA). Morphological identification under a stereomicroscope proved the identity of F. pongamiae. Pathogenicity was established by artificial inoculation on healthy seedlings, which proved to cause typical symptoms. In dual culture assays, the maximum inhibition of F. pongamiae was caused by P. fluorescens (68.46%), followed by the combination of T. viride and P. fluorescens (61.46%), and T. viride (53.79%). Using poisoned food technique assays, 0.1% Carbendazim strongly inhibited mycelial growth (83.82%), followed by 5% Pongam oil (41.28%). The research concludes that P. fluorescens has high biocontrol activity against F. pongamiae, while Carbendazim is the most efficient antifungal agent. These results justify the combination of biological and chemical approaches for sustainable control of leaf spot and blight disease in M. pinnata, resulting in better plant health and productivity in afforestation schemes.