Green and Chemical Synthesis of Copper Oxide Nanoparticles for Antifungal Protection and Plant Growth Enhancement of Chickpea via Nanopriming

This study reports the synthesis of copper oxide nanoparticles (CuO NPs) using chemical and green methods utilizing pineapple waste, including fresh peels, dried peels, and pineapple pomace from two different copper precursors, targeting antifungal activity and plant growth enhancement. Phytochemical analysis confirmed the presence of bioactive compounds with dry peel extract proving to be most effective for green synthesis. CuO NP formation was evidenced by color change and confirmed by UV-vis, Fourier transform infrared (FTIR), X-ray diffraction (XRD), and transmission electron microscopy (TEM) analysis, revealing particle sizes under 50 nm. Green CuO NPs (GN) exhibited a better stability and superior antifungal activity against Fusarium oxysporum f. sp. ciceri (64.20% inhibition at 1000 ppm), was lower than those of chemically synthesized NPs and precursors. In chickpea seed priming, GN significantly enhanced germination (100%), root length (11.3 cm), and seedling length (13.9 cm) at 250 ppm, indicating improved root-to-shoot balance and biomass accumulation. Thus, pineapple waste-derived CuO NPs offer a sustainable, eco-friendly solution for both disease management and growth promotion in chickpea.