Biocontrol Potential of Trichoderma Ghanense and Trichoderma Citrinoviride toward Pythium aphanidermatum

-induced damping-off of cucumber is a major constraint to cucumber production in different parts of the world. Although chemical fungicides are used for managing this disease, they have many drawbacks to the environment. The ability of the antagonistic fungi isolated from the rhizosphere and endosphere of and in the control of soilborne pathogen was inspected. Native isolates, and , were isolated from plant stem and soil samples collected from Al-Seeb, Oman. Using a dual culture technique, the antagonistic activity of the fungal isolates against was examined in vitro. Among isolates, was more efficient in restraining the mycelial growth of , causing an inhibition percentage of 44.6%. Further, induced significantly lower cessation of mycelial growth (31.3%). Microscopic and electrolyte leakage inspection of the pathogen mycelia depicted extreme morphological malformations in their mycelium, which can be attributed to the antifungal metabolites of antagonists. Greenhouse studies demonstrated the effectivity of in controlling damping-off of cucumber plants, where the number of surviving plants was over 90% when the biocontrol agents were used compared to 0 in the control plants. Furthermore, treatment of the plants with the antagonists promoted growth characteristics of plants compared to uninoculated plants. This included improvements in shoot and root lengths, leaf length and width, and dry weight. These findings suggest that and can be developed as alternatives to synthetic chemical fungicides to manage soilborne pathogens of cucumber. This research is also the first to clarify the biocontrol ability of and against cucumber damping-off caused by .