SCREENHOUSE EVALUATION OF Trichoderma viride AND Trichoderma harzianum FOR THE INTEGRATED MANAGEMENT OF CUCUMBER MOSAIC VIRUS AND FUSARIUM WILT IN TOMATO IN CALABAR, CROSS RIVER STATE, NIGERIA.
TL;DR
These findings demonstrate that both Trichoderma species function as multifunctional bioagents capable of simultaneously suppressing fungal and viral diseases while promoting tomato growth, with T. viride showing superior overall efficacy and strong potential for sustainable integrated disease management.
Abstract
The dependence on synthetic fungicides in smallholder vegetable production creates both an economic and environmental concerns in sub-Saharan Africa. This study evaluated the biocontrol potential of two molecularly identified Trichoderma isolates, T. viride and T. harzianum, against Fusarium oxysporum and Cucumber mosaic virus (CMV) in tomato under controlled screenhouse conditions. The isolates were characterized using morphological traits and confirmed by ITS and tef1 sequencing. In vitro antagonism against F. oxysporum was assessed using serial spore concentrations, while in vivo efficacy was evaluated through pathogen challenge experiments measuring disease incidence, severity, plant growth, chlorophyll content, biomass, and root colonization over 12 weeks. Both isolates significantly suppressed pathogen activity, with T. viride showing stronger overall performance. In vitro, T. viride achieved 94.3% inhibition of F. oxysporum at 10⁹ CFU mL⁻¹ after 120 hours, compared with 91.7% for T. harzianum at same end point. Under screenhouse conditions, T. viride reduced Fusarium wilt incidence by 67% and CMV severity by 67%, whereas T. harzianum reduced Fusarium wilt incidence by 60% and CMV severity by 59% relative to pathogen-inoculated controls. Plants treated with T. viride also exhibited the greatest plant height, chlorophyll content, biomass accumulation, and root colonization, indicating enhanced plant vigour. In contrast, carbendazim effectively suppressed Fusarium wilt but provided no protection against CMV. These findings demonstrate that both Trichoderma species function as multifunctional bioagents capable of simultaneously suppressing fungal and viral diseases while promoting tomato growth, with T. viride showing superior overall efficacy and strong potential for sustainable integrated disease management.