Foliar Nutrient Applications: Boosting Productivity and Quality of Picual Olive Fruits and Oils

Olives are one of the economic and important fruit crops in the Mediterranean basin countries, including Egypt. One of the most important types of oils is olive oil, which has many nutritional and medical benefits. Olives are one of the economic and important fruit crops in the Mediterranean basin countries, including Egypt. One of the most important types of oils is olive oil, which has many nutritional and medical benefits. Olive oil exports also contribute to the economies of many countries around the world. Despite this, olive trees have suffered productivity problems in recent years for a variety of reasons, including climate change and nutritional reasons. We applied foliar spraying of algae extract, zinc sulfate, and boric acid at different concentrations at three spraying times to olive trees of the Picual cv. in a private orchard located at Ismailia Governorate, Egypt, during the 2022-2023 growing seasons, in an attempt to improve tree productivity, fruit characteristics, and oil quality, The results demonstrated that foliar spraying with 0.2% algae extract, 3000 ppm zinc sulfate, and 300 ppm boric acid resulted in the highest final fruit set, yield, fruit weight, flesh weight, fruit oil content, and potassium content in the leaf. Additionally, the majority of treatments positively impacted oil characteristics such as acidity value, peroxide value, iodine value, and the percentage of unsaturated fatty acids in the oil. Therefore, we recommend applying these treatments to olive trees planted on lands with similar conditions.