Efficacy of Seed-Biopriming with <i>Trichoderma</i> spp. and Foliar Spraying of ZnO-Nanoparticles Induce Cherry Tomato Growth and Resistance to <i>Fusarium</i> Wilt Disease

Several microbes that cause plant diseases drastically lower the production of agriculture and jeopardize the safety of the world’s food supply. As a result, sustainable agriculture requires disease management tactics based on modern, eco-friendly techniques as alternatives to various agrochemicals. The current study aimed to assess the antifungal activity of ZnO-nanoparticles against <i>Fusarium solani</i> in-vitro, and the ability of two antagonistic <i>Trichoderma</i> isolates, <i>Trichoderma viride</i> and <i>Trichoderma harzianum</i>, to produce antifungal secondary metabolites and identify them using gas chromatography–mass spectrometry, and to evaluate the combined effects of foliar spray of ZnO-nanoparticles and bioprimed seeds of cherry tomato (<i>Solanum lycopersicum</i> L.) with two antagonistic <i>Trichoderma</i> isolates against <i>Fusarium</i> wilt disease caused by <i>Fusarium solani</i> in greenhouse conditions. The results revealed that, in-vitro, the highest concentration of ZnO nanoparticles (3000 ppm) resulted in the greatest decrease in <i>Fusarium solani</i> mycelial growth (90.91% inhibition). The scanning electron microscopy demonstrated the evident distortion in <i>Fusarium solani</i> growing mycelia treated with ZnO-nanoparticles, which might be the source of growth suppression. Additionally, twenty-eight bioactive chemical compounds were isolated and identified from <i>Trichoderma</i> spp. ethyl acetate crude extracts using gas chromatography–mass spectrometry. In a greenhouse experiment, the combination of bioprimed cherry tomato plants with <i>Trichoderma harzianum</i> and foliar spraying of ZnO-nanoparticles at 3000 ppm was the most effective interaction treatment for reducing disease severity index (23.4%) and improving the vegetative growth parameters, micronutrient contents (Mn, Zn, and Fe in leaves), and chlorophyll content (SPAD unit), as well as stimulating phenylalanine ammonia-lyase activity of cherry tomato leaves at 75 days after sowing. In conclusion, the antifungal potential of seed-biopriming with antagonistic <i>Trichoderma</i> isolates and the foliar spraying of ZnO-nanoparticles can boost cherry tomato growth and confer resistance to <i>Fusarium</i> wilt caused by <i>Fusarium solani</i>.