Use of Trichoderma spp. as Biocontrol Agents to Enhance Disease Tolerance in Tomatoes

There is growing interest in the use of Trichoderma spp., beneficial soil fungi, as a sustainable alternative to chemical plant protection products in the cultivation of tomato (Solanum lycopersicum). This study aimed to evaluate the efficacy of three Trichoderma species (T. hamatum, T. virens and T. asperellum), isolated from the rhizosphere of tomato plants in Côte d'Ivoire, as biocontrol agents to enhance tomato tolerance to various pathogens. The isolates were characterized through morphological observations and molecular analyses. Phylogenetic analysis revealed a high degree of similarity between the locally isolated species and those previously identified in China. The impact of these Trichoderma strains on tomato plant roots was assessed, showing a significant increase in root dry matter, with results comparable to those obtained using chemical fertilizers, relative to the untreated control. Symptoms of wilting and chlorosis were observed in both control plants and those treated with either Trichoderma isolates or a chemical plant protection product. However, plants treated with T. asperellum exhibited a higher (10 %) incidence of wilt. In contrast, T. virens and T. hamatum contributed to enhanced disease resistance and greater tolerance to abiotic stresses in tomato plants.