Olive Oil Qualitative Parameters after Orchard Irrigation with Saline Water

The effect of irrigation with saline water on oil quality was studied in the two olive (Olea europaea L.) cultivars Koroneiki and Mastoidis, which are the main varieties grown extensively on the island of Crete. Plants (5 years old) were grown outdoors in containers, filled with freely drained light soil. Four treatments were applied, differing in the NaCl added to the irrigation water as follows: 0 (control) 50, 100, and 150 mM NaCl. Drip irrigation was applied regularly, during the dry season (from April to October). Plants in all treatments were irrigated when the soil-water potential reached -40 kPa at a depth of 30 cm. Data showed that increased NaCl levels in irrigation water resulted in a decrease in oil content in the fruits and an increase in total phenols and their secoiridoid derivatives in olive oils from harvested fruits. Furthermore, changes also took place in the composition of fatty acids and triacylglycerol molecular species. The extent of alterations was different for the two varieties and greater in cv. Koroneiki. This fitted with agronomic evidence that cv. Koroneiki is less saline-tolerant than cv. Mastoidis.