Abstract
This study aimed to evaluate how foliar spraying of zinc, potassium, and ethrel impacts the yield, quality, shelf-life, and postharvest characteristics of Crimson Seedless grapevines. This study was conducted on eight-year-old Crimson Seedless grapevines cultivated in sandy soil over two seasons (2022 and 2023). Zinc sulfate, irradiated zinc sulfate, potassium silicate, irradiated potassium silicate, ethrel, and their combination were sprayed on vine leaves. The data indicated that gamma-irradiated potassium silicate or ethrel was the most effective single foliar treatment. Ethrel was superior in terms of most berry physical and chemical characteristics, as well as leaves P and K percentage, whereas irradiated potassium was better in terms of firmness, yield, leaf N percentage, weight loss, and adherence. The combination of ethrel with potassium and zinc, whether irradiated or not, proved to be the best foliar spray throughout the experiment. Compared with ethrel and zinc, potassium and ethrel improved most parameters. In conclusion, foliar potassium spray, especially in the irradiated form, could be a viable alternative to ethrel. The combination of ethrel, zinc, and potassium may enhance the coloring of Crimson Seedless grapevines while also improving berry quality, shelf life, and postharvest characteristics.