Antifungal and plant-growth promoting potency of Trichoderma asperellum against Fusarium wilt on tomato

One of the most well-known vegetables used by the majority of the population worldwide, known as tomato (Solanum lycopersicum), is affected by wilt disease caused by Fusarium oxysporum f. sp. lycopersici (FOL), mainly in the tropics. In the current scenario, a residue-free management approach using a biological control agent is being explored to address the invasion of phytopathogens. This investigation assessed the ability of Trichoderma asperellum (Tv1) to reduce pathogen growth and promote plant growth. A dual culture assay demonstrated that Trichoderma asperellum Tv1 inhibited the growth of the pathogen mycelia by up to 79.63%, and volatile organic compounds (VOCs) emitted by the antagonist inhibited FOL to a maximum of 61.48% of the MGI. An oil-based (OB) formulation was developed using a spore suspension of Tv1 with improved shelf life (3.22 × 10⁸ cfu/ml on the 120th day). Compared with those in the control treatment, significant improvements in vegetative parameters such as germination percentage (100%), root length (8.12 cm) and shoot length (5.58 cm) were observed by the roll towel method upon seed treatment (5 ml/kg) with the OB formulation. There was a minimum wilt disease incidence in tomatoes, up to 19.34% (T8), which was recorded in comparison with that in the inoculated control (T12) (64.75%). Overall, Trichoderma asperellum Tv1 was proven to be an effective biocontrol agent against Fusarium wilt disease in tomato. This study revealed a reduction in mycelial growth of the pathogen caused by mycoparasitism and VOCs under laboratory conditions and wilt disease incidence in a glasshouse study in response to treatment with the biocontrol agent Tv1. With this viewpoint, this approach could be considered a promising environmentally safe approach for managing wilt disease in tomatoes.