Evaluation of biocontrol efficacy of trichoderma harzianum against fusarium oxysporium in tomatoes ( <i>Solanum esculentum L.</i>)

Abstract

Utilizing biological techniques to manage plant diseases has demonstrated efficacy in fostering ecosystem sustainability and augmenting  agricultural output and quality. A study was undertaken at the Department of Plant Science and Biotechnology, Imo State  University, Owerri, Nigeria to evaluate the suppressive impact of T. harzianum on the proliferation of F. oxysporusm f. sp. lycopersici, and  the advancement of F. oxysporum infection in tomato plants. The trial comprised culturing only T. harzianum in the Petri dish, culturing T.   harzianum and F. oxysporum in the Petri dish (dual culture), and culturing only F. oxysporum in the petri dish, and with Mancozeb. The  influence of T. harzianum on the advancement of F. oxysporum infection in tomato plants comprises of four distinct concentrations (1g, 2g,  3g, and 4g) of T. harzianum extract. The results revealed that the dual culture of T. harzianum and F. oxysporum successfully  suppressed the mycelial growth of F. oxysporum. On the seventh day, the level of antagonistic activity exhibited by T. harzianum against F.  oxysporum peaked at 9.05mm. Leaf yellowing and severe wilting, indicative of Fusarium wilt, were seen during the monitoring period.  Tomato disease incidence and severity exhibited a consistent linear decline with increasing concentrations of T. harzianum. The disease  severity reached its maximum level, (31.6%) on week four. Mancozeb treatment compared favorably with 4g T. harzianum in decreasing  the mycelial growth of F. oxysporium, and reducing wilt incidence and severity. Therefore, T. harzianum can function as a biocontrol  agent, providing a sustainable substitute for synthetic fungicides in the control ofFusariumoxysporium wilt disease.