Chitosan Nanoparticles Enhance Yield and Bioactive Compounds in Melon Fruits

Chitosan nanoparticles (CSNPs), a product of nanotechnology, have emerged as promising biostimulants with significant applications in sustainable agriculture for enhancing crop yield and quality. In this study, the effects of foliar-applied CSNPs on yield and bioactive compounds in melon (Cucumis melo L.) fruits were evaluated. Five increasing concentrations of CSNPs (0, 0.2, 0.4, 0.6, and 0.8 mg mL−1) were foliarly applied. The foliar spraying of CSNPs exerted positive effects on fruit productivity and nutraceutical attributes. The most significant yield and commercial quality were achieved with the 0.4 mg mL−1 dose. In contrast, the 0.8 mg mL−1 dose was most effective in enhancing optimal postharvest characteristics, including fruit firmness and reduced weight loss, as well as stimulating the accumulation of bioactive compounds (such as flavonoids and vitamin C) and antioxidant capacity. In the case of phenols, the highest total phenolic content was observed at concentrations of 0.6 and 0.8 mg mL−1. Therefore, the foliar application of CSNPs constitutes a versatile and sustainable strategy, allowing for the tailoring of application doses to either maximize yield or enhance the functional and postharvest quality of melon fruits.