Mitigation of Early Blight in Tomato Plant: Evaluating Trichoderma harzianum, Cassia fistula and Azadirachta indica leaves powder

Early blight, caused by the fungus Alternaria solani , is a significant challenge in tomato cultivation, often leading to yield losses. In this study, we investigated the potential of three natural substances: Trichoderma harzianum (spore suspension), Cassia fistula and Azadirachta indica (leaves powder) in mitigating early blight. These substances were applied individually and in combination with all of three substances as treatments to evaluate their efficacy in disease suppression in tomato seedlings. The experiment was conducted in a Completely Randomized Design with three replications. After 15 days of various growth parameters like root and shoot length, fresh and dry weight were studied. Furthermore, the biochemical (Catalase and Peroxidase activities) and physiological (Total protein content and reducing sugar) attributes of tomato plants were also investigated. The results revealed that the growth parameters of tomato seedlings were significantly declined by 70 to 80% when infested by early blight disease. However, soil amendments with T. harzianum  +  C. fistula nullify the effect of the pathogen and increased the plant growth. Furthermore, the physiological and biochemical traits exhibited more production (up to 90%) and less activity (~ 20 to 30%), respectively in plants when plants were grown in T. harzianum  +  C. fistula in comparison with control. The trend of better growth in plants was T. Harzianum  +  C. fistula  >  T. harzianum  >  C. fistula >. Therefore, the soil amendment with T. Harzianum  +  C. fistula in pathogen-infested soil could be implemented to combat the early blight of disease. The results indicated that bio-agents such as C, fistula and A, indica in combination with Trichoderma can be used in antifungal products. Overall, this study highlights the promising role of natural substances in integrated pest management strategies for sustainable tomato cultivation. Further research is warranted to elucidate the underlying mechanisms of action and optimize application protocols for maximizing efficacy while minimizing environmental impacts.