Biological Control of Fusarium oxysporum f. sp. melonis by Trichoderma atroviride in Melon Under Greenhouse Conditions

Abstract

Fusarium wilt caused by Fusarium oxysporum f. sp. melonis is one of the most destructive soil-borne diseases affecting melon production, particularly under greenhouse cultivation where environmental conditions favor pathogen survival and spread. The disease leads to vascular discoloration, wilting, reduced plant vigor, and significant yield losses. Biological control using antagonistic fungi has emerged as an environmentally sustainable alternative to chemical fungicides for the management of soil-borne pathogens. The present study was conducted to evaluate the biocontrol potential of Trichoderma atroviride against F. oxysporum f. sp. melonis in greenhouse-grown melon plants. Fungal isolates of T. atroviride were cultured and assessed for antagonistic activity against the pathogen through in vitro dual culture assays and greenhouse experiments. Disease incidence, disease severity, plant growth parameters, and pathogen suppression were recorded to determine the effectiveness of the biocontrol agent. The results demonstrated that T. atroviride significantly inhibited the mycelial growth of F. oxysporum f. sp. melonis under laboratory conditions through competition and antagonistic interactions. Greenhouse trials further revealed a substantial reduction in wilt incidence and disease severity in treated plants compared with untreated controls. Melon plants treated with T. atroviride exhibited improved root development, enhanced plant vigor, and greater biomass accumulation, indicating additional plant growth-promoting effects of the antagonist. The suppressive activity of T. atroviride was associated with rapid root colonization and potential production of antifungal metabolites and hydrolytic enzymes.