Eco-friendly nanoparticle-based strategy for controlling Fusarium wilt in tomato using biosynthesized copper oxide...

Fusarium wilt, caused by Fusarium oxysporum f. sp. lycopersici (Fol), severely limits tomato productivity, while excessive use of chemical fungicides raises environmental and resistance concerns. This study reports the green synthesis of copper oxide nanoparticles (CuO NPs) using neem (Azadirachta indica L.) leaf extract and evaluates their antifungal and growth-promoting effects. UV-vis, FTIR, and SEM analyses confirmed successful nanoparticle formation; the slightly blue-shifted UV-vis absorption band (250-320 nm), frequently observed in plant-mediated CuO NP synthesis, is attributed to phytochemical capping effects. The absence of XRD, TEM, and Zeta potential analyses due to laboratory limitations is acknowledged and discussed. In vitro assays showed enhanced germination and seedling vigor at 25 ppm, while antifungal activity increased in a dose-dependent manner, reaching 97.6% disease suppression at 100 ppm. Comparative controls-including neem extract alone and CuSO₄ solution-were included to distinguish nanoparticle-specific effects. Greenhouse trials demonstrated reduced wilt incidence, improved plant growth, and increased phenolic and proline accumulation, indicating activation of host defense pathways. Overall, neem-mediated CuO NPs functioned as dual-action agents-potent antifungals and growth stimulants-highlighting their novelty and potential as an eco-friendly, sustainable alternative to chemical fungicides for tomato wilt management.