Evaluation of the Antifungal Effect of Green Synthesized Metal Oxide Nanoparticles Against Plant Pathogenic Rhizoctonia Species

The current study successfully synthesized zinc oxide (ZnO), copper oxide (CuO), and iron oxide (FeO) nanoparticles (NPs) using cost-effective and environmentally friendly procedures. The synthesized NPs were characterized by UV-Vis spectroscopy and SEM analysis. UV-Vis spectroscopy revealed characteristic absorption peaks at 356 nm for ZnO NPs, confirming their synthesis. SEM analysis showed a heterogeneous distribution of nanoparticle sizes, with ZnO NPs averaging 81 nm, CuO NPs averaging 108 nm, and FeO NPs averaging 82 nm. The antifungal activity of the synthesized nanoparticles was evaluated at various concentrations using the poisoned food technique. The results indicated a dose-dependent inhibition of mycelial growth by ZnO and CuO NPs, with higher concentrations (500 and 1000 mg/L) showing significant inhibition compared to untreated Rhizoctonia species. Specifically, CuO NPs exhibited mycelial growth inhibition percentages of 70.64% and 73.43% at 500 and 1000 mg/L, respectively, while ZnO NPs showed inhibition percentages of 78.38% and 80.94% at the same concentrations. Statistical analysis using one-way ANOVA revealed significant differences among the treatment groups (p < 0.001). In contrast, FeO NPs did not exhibit a dose-dependent inhibition of mycelial growth but showed a minor, statistically insignificant promotion. Among the tested NPs, CuO NPs at 1000 mg/L achieved the highest inhibition, followed by ZnO NPs. The observed variations in mycelial inhibition by different nanoparticles at various concentrations underscore the complexity of nanoparticle-pathogen interactions and highlight the need for further research to optimize their antifungal efficacy.