Antifungal activity of Trichoderma species and vermiwash against rice blast fungus (Magnaporthe oryzae)

Rice blast, caused by Magnaporthe oryzae, is a global fungal disease affecting rice. Fungicides are used to manage the disease, although they can harm the environment and human health. This study evaluates the antifungal efficacy of Trichoderma isolates (BG-1, SYA-E, BRO-2, SYA-C, EM-B) and vermiwash against M. oryzae using in vitro dual culture assays. Seven vermi-bacterial isolates from Eisenia fetida were analyzed through Gram staining and biochemical analysis. M. oryzae isolated from infected rice tissues and Trichoderma, along with 10% dilution rice straw vermiwash were placed 7 cm apart on 9 cm potato dextrose agar plates and incubated at 25 ± 2°C. Pearl 500SC fungicide (1 mL) and distilled water were used as controls. A completely randomized design (CRD) with three replications was used and data on the radial growth of the isolates were collected over seven days. The biocontrols differed significantly from the controls at p ≤ 0.05. Vermiwash, EM-B, and SYA-C exhibited the highest antifungal activity, with inhibition rates of 72.81, 71.49, and 71.05%, respectively, indicating their potential against rice blast disease. Further research is warranted on these Trichoderma isolates and vermiwash in greenhouse and field experiments.  Key words: Bacteria, biocontrol, in-vitro, isolates, rice blast, sustainable disease management.