Enhancing leafy green vegetable growth and quality through the foliar application of copper oxide nanoparticles

The application of nanotechnology to enhance crop yield has garnered growing interest. The present work investigated the effects of copper oxide nanoparticles (CuO NPs) on the development of Chinese cabbage (Brassica pekinensis (Lour.) Rupr.) and spinach (Spinacia oleracea L.). In the greenhouse study, upon a foliar treatment with CuO NPs (80 mg/L), the fresh shoot biomass of Chinese cabbage and spinach was significantly increased by 29.06 % and 26.34 % respectively, compared to the untreated control. Meanwhile, no significant differences were observed between the foliar treatments with CuSO₄, bulk CuO, and the untreated control. Notably, CuO NPs enhanced the concentrations of Fe, Mg, and Zn by 112.3 %, 37.9 %, and 36.5 % in Chinese cabbage, and 59.4 %, 30.3 %, 15.4 % in spinach, and increased the levels of organic compounds such as vitamin C and carotene in leaves by 51.89 % and 42.24 % as compared to the untreated control, which are beneficial for human health. Compared to the untreated control, the concentration of carotene in spinach leaves increased by 42.24 %, and the concentration of vitamin C in Chinese cabbage leaves increased by 51.89 %. Taken together, our findings provide valuable information and an approach for improving the yield and quality of leafy green vegetables.