Abstract

nano-Magnesium Oxide nanoparticles (n-MgO) have garnered significant attention in recent decades, particularly in the agricultural sector, due to their exceptional properties, such as antifungal potency and the ability to promote plant growth. In this study, the ultrasound-mediated sol-gel method was employed to synthesize n-MgO. Various physicochemical characterization techniques, including Ultraviolet-visible spectrometry, Fourier-transform infrared spectroscopy, and X-ray diffraction, were used to confirm the formation of n-MgO. Additionally, the study assessed the antifungal activity of n-MgO against the plant pathogenic fungus <em>Fusarium oxysporum</em> (<em>F. oxysporum</em>). The disc diffusion method was used to determine the effectiveness of n-MgO in inhibiting the growth of <em>F. oxysporum</em>. Subsequently, the Minimum Inhibitory Concentration (MIC) required to suppress the growth of <em>F. oxysporum</em> was determined through a broth microdilution study.  Furthermore, a field study was conducted to evaluate the plant growth promotion capabilities of n-MgO. The results indicated an inhibition zone of 8.74 ± 0.16 mm, with an MIC of 2.5 mg/mL, suggesting that n-MgO effectively inhibit the growth of <em>F. oxysporum</em>. Moreover, the application of n-MgO in the field study resulted in a 5.78% increase in the height of maize plants. Consequently, it can be concluded that n-MgO holds significant potential as an effective agrochemical product with dual functions as a fungicide and a plant growth promoter.