Biosynthesized ZnO nanoparticles (NPs) vs. commercially available NPs: Protecting mung bean against wilt and web blight

The modification of climatic conditions enhances the survival capacity of pests and pathogens, resulting in detrimental effects on crop yield and a reduction in its economic value. Nano-based agricultural pesticides provide a distinctive method to improve productivity and manage phytopathogens, employing nanotechnology with low environmental consequences. Laboratory and greenhouse experiments were conducted to evaluate the efficacy of zinc-oxide nanoparticles (ZnONPs) produced by bacterial strains in mitigating wilt and web blight infections caused by Fusarium oxysporum and Rhizoctonia solani, while also improving the growth and quality of mung bean crops (Vigna radiata). The ZnONPs were comprehensively studied and stabilized using several techniques, including UV Vis Spectroscopy , X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy, and scanning and transmission electron microscopy (SEM and TEM), energy dispersive X-ray spectroscopy (EDX), Hydrodynamic size and surface charge (Zeta & DLS) . The X-ray diffraction (XRD) examination revealed the existence of a cubic magnetite (ZnO) phase displaying super-paramagnetic properties. The particles were verified to be homogenous and exhibit either a spherical or cubic morphology, with an average diameter of 23 nm, using SEM and TEM analysis. The EDX spectra confirm the existence of ZnONPs with peaks corresponding to impurities Exposure to several Pseudomonas flourescense Zinc Oxide nanoparticles (PF-ZnONP) treatments led to a significant reduction in mycelia development and spore germination. PF-ZnONPs demonstrated a significant reduction in disease severity, averaging 47.8%. This resulted in improved plant growth traits after exposure to a concentration of 250 µg/mL of PF-ZnONPs. Analysis of photosynthetic pigments, phenolic compounds, and antioxidant enzymes in the roots and shoots demonstrated a gradual increase (75.6% and 77.7%, 2.02 and 2.04 folds, 70 to 80%) subsequent to exposure of dose of PF-ZnONPs. The results of the present study indicated that the synthesized ZnONPs possess anti-fungal and nutritional properties that can assist in the management of Fusarium wilt disease and web blight, thereby improving the quality of growth of plants.