Evaluation of Trichoderma Isolates for their Biocontrol Potential and Plant Growth Promoting Activity

Trichoderma species are well-known for their biocontrol potential and plant growth-promoting abilities. The research conducted used ITS sequencing analysis to pinpoint eight different Trichoderma isolates. A phylogenetic tree confirmed their genetic relationships with known species of Trichoderma, including T. yunnanense, T. atrobrunneum, T. longibrachiatum, and T. harzianum. During Dual culture tests, T. harzianum (SPT6) showed the highest level of inhibition (79.91%) against Sclerotinia sclerotiorum. The ability to solubilize phosphate, produce IAA, and exhibit siderophore activity differed among the various isolates, with SPT6 demonstrating the greatest amounts of soluble phosphorus and IAA (45.95 μg/ml). The volatile substances released by Trichoderma isolates significantly hindered the growth of S. sclerotiorum mycelium (38 to 62.43%). In a greenhouse study, tomato seeds treated with T. harzianum in treatment T1 achieved the highest germination rates (93.66%) and seedling vigor (2088.77). T1 reduced the damping off of seedlings, resulting in the lowest mortality rate (1.66%) among seeds treated with Trichoderma. There were improvements in growth factors such as shoot and root length, as well as fresh and dry weight, due to Trichoderma treatment, with SPT6 showing the most significant impact compared to other treatments. These findings highlight the potential of Trichoderma isolates as effective biocontrol agents and their ability to enhance plant growth, suggesting they could be useful in sustainable farming practices.

⓿ Trichoderma harzianum (SPT6) showed the maximum inhibition of Sclerotinia sclerotiorum and the highest phosphate solubilization, IAA and siderophore production. Seed treatment with SPT6 improved tomato germination, vigour and significantly reduced damping off, highlighting its strong biocontrol and growth promoting potential.