In vitro evaluation of antagonistic potential of Trichoderma isolates against Fusarium oxysporum f. sp. capsici in hot pepper

Hot pepper (Capsicum annuum L.) is the most important vegetable crop in Ethiopia. However, its production and productivity are much lower than the world average due to Fusarium wilt disease caused by Fusarium oxysporum f. sp. capsici (FOC). In Ethiopia, this disease can cause up to 80% yield loss in hot pepper crops. Therefore, an in vitro experiment was conducted to characterize and evaluate the antagonistic activity of Trichoderma isolates for the management of Fusarium oxysporum f. sp. capsici using a dual culture assay in the plant protection laboratory at the University of Gondar, Ethiopia, in 2022. A total of nine treatments (including the control) were implemented in a completely randomized design with three replicates, and the data were analyzed using SAS 9.4. The study’s results indicated that out of the eight tested Trichoderma isolates, seven (T. asperellum, Tri-9, Tri-11, Tri-18, Tri-20, Tri-26, and Tri-27) exhibited effective antagonistic effects against FOC, with colonization percentages of 84.09, 83, 65.15, 76.51, 53.05, 78.82, and 68.18%, respectively, as compared to Tri-30 and the control with the inhibition of 40.91 and 00.00%, respectively. Thus, T. asperellum followed by Tri-9 demonstrated significantly superior effectiveness compared to the other strains. Consequently, the study recommends T. asperellum followed by Tri-9 for the effective management of Fusarium oxysporum f. sp. capsici in hot peppers.