In vitro Antagonistic Activity of Trichoderma Spp. Against Fusarium Oxysporum F. Sp. Niveum Causing Wilt in Watermelon

AbstractFusarium wilt of watermelon, caused by Fusarium oxysporum f. sp. niveum (FON), is a destructive soil-borne disease resulting in severe yield losses worldwide. Biological control of this disease using antagonistic fungi, such as, Trichoderma spp. presents an eco-friendly alternative to chemical fungicides. Present study evaluated in vitro antagonistic potential of three Trichoderma species (T. viride, T. harzianum, and T. asperellum) against two isolates of Fusarium oxysporum differing in sensitivity to the fungicide Roko (Fon-3: sensitive; Fon-10: resistant). Dual culture assays revealed that all Trichoderma spp. significantly inhibited mycelial growth of Fusarium oxysporum. Trichoderma viride showed highest inhibition, (72.60 % for Fon-3) and (77.16 % for Fon-10), followed by T. harzianum (61.98% and 66.43% respectively) and T. asperellum (61.85% and 61.24% respectively). These results highlighted strong antagonistic potential of Trichoderma spp. and suggested their suitability biological control agents for managing Fusarium wilt of watermelon.