Antifungal and plant growth promoting activity of Trichoderma spp. against Fusarium oxysporum f. sp. lycopersici colonizing tomato.

Fusarium wilt, incited by Fusarium oxysporum f. sp. lycopersici (FOL), causes serious production losses of tomato (Solanum lycopersicum L.) plants. Biological control, using an antagonistic of Trichoderma species, is a bio-rationale and an alternative method to synthetic pesticides against most phytopathogens. The present study was undertaken to evaluate the effects of T. harzianum and/or T. viride in reducing Fusarium wilt and to determine the relationship between disease severity and plant growth promoting traits of these species. Trichoderma viride exhibited better phosphate solubilization and production of cellulases, ligninases, chitinases, proteases, hydrogen cyanide (HCN), siderophores and indole acetic acid (IAA) than T. harzianum. For field assessment, five treatments with three replicates were used. The field was inoculated with the wilt fungus (FOL). Both Trichoderma spp. used were applied as a seed treatment, mixed in the soil, and FOL inoculated soil served as the untreated control. During the two consecutive years, seed treatment with T. viride exhibited the least disease severity, the highest physiological activity, the highest biochemical and antioxidant contents, and tomato plants treated with it exhibited the best growth and yield. It was concluded that Trichoderma viride can potentially be used to reduce Fusarium wilt and promote plant growth and yield in commercial tomato production. [ABSTRACT FROM AUTHOR]