Biogenic ZnO Nanoparticle From Vachellia erioloba : Evaluation of Its In Vitro Antifungal Potential Against Fungi Associated With Soybean ( Glycine max L. Merr)

Zinc oxide nanoparticles (ZnONPs) are considered safe and are recognized for their potential to promote eco‐friendly management of soybean disease. Conventional management strategies involve the use of chemical fungicides, which contaminate groundwater. This study reports the eco‐friendly synthesis of ZnONP using Vachellia erioloba leaf extract and investigates the antifungal efficacy against Aspergillus brasiliensis _NWU‐OBE‐004, Aspergillus aflatoxiformans _NWU‐OBE‐009, Fusarium pseudoanthophilum _NWU‐OBE‐003, Fusarium longifundum _NWU‐OBE‐001, Laetisaria arvalis _NWU‐OBE‐006 and Chaetomium strumarium _NWU‐OBE‐010, which are associated with diseased soybeans. ZnONPs were characterized using ultraviolet–visible (UV), Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD) and electron microscopy. XRD studies revealed the particles' crystallinity, with a crystallite size of 18.70 nm. Microscopic analyses confirmed a spherical morphology (13.09 nm), while absorption spectroscopy showed a peak at around 365 nm and FTIR spectroscopy identified the functional group associated with the NPs. Overall, a moderate mycelial growth inhibition at the 50 μg/mL concentration across the test fungi was observed and only the inhibition against L. arvalis _NWU‐OBE‐006 at this dose was significantly different from the positive and negative controls ( p < 0.05). Furthermore, no significant growth inhibition was observed against all fungi at the maximum dose, except F. pseudoanthophilum _NWU‐OBE‐003, which was found to be significantly different ( p < 0.05) from the negative control, but not significantly different from the positive control ( p > 0.05). This study presents preliminary findings on the potential use of V. erioloba ‐mediated ZnONP for the eco‐friendly management of diseases caused especially by F. pseudoanthophilum _NWU‐OBE‐003 in soybean‐growing regions.