ECO-SUSTAINABLE COPPER NANOPARTICLES SYNTHESIZED FROM CARICA PAPAYA LEAVES FOR MANAGEMENT OF RHIZOME ROT PATHOGENS IN GINGER (ZINGIBER OFFICINALE)

Abstract

Background: The investigation of phyto-directed nanoparticle synthesis techniques is driven by the increasing need for sustainable disease management in agriculture. Methodology: In this work, aqueous extracts of Carica papaya leaves were utilized as both stabilizing and reducing agents during the biological synthesis of copper nanoparticles (CuNPs). To verify the size, shape, crystallinity, stability, heterogeneity, and surface chemistry of CuNPs, they were assessed using UV-Vis, infrared (IR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), Horiba analysis, polydispersity index (PDI), and zeta potential. Result and Discussion: The results demonstrated that the average particle size ranged between 6.5 and 38.25 nm. Produced CuNPs showed improved stability and applicability with a low polydispersity index (0.132) and high zeta potential (-27.2 mV), demonstrating improved applicability and stability. Using the agar diffusion method, antifungal experiments were carried out against the main ginger pathogens that cause soft rot disease, particularly Rhizopus spp. and Fusarium spp. CuNPs had a minimum inhibitory concentration (MIC) of  5 µg/mL and a minimum fungicidal concentration (MFC) of 10 µg/mL against the test pathogens. According to morphological evaluation using scanning electron microscopy, exposure to nanoparticles caused noticeable structural damage to Fusarium hyphae and a significant suppression of fungal growth. Conclusion: This work shows that papaya leaf-mediated CuNPs have the potential to be an economical and environmentally beneficial method of controlling rhizome rot in ginger farming.