Effect of Regulated Deficit Irrigation on the Quality of 'Arbequina' Extra Virgin Olive Oil Produced on a Super-High-Intensive Orchard

The expansion of the super-high-intensive cultivation of olive groves requires irrigation techniques that are compatible with the increasing scarcity of water due to climate change and olive oil demand. For this, the effect of two regulated deficit irrigation treatments (RDI) and a sustained deficit irrigation (SDI) treatment was studied. The treatments consisted of: (i) control treatment, which supplied 100% of the water lost by evapotranspiration (ET0); (ii) the "optimal RDI" treatment, which only reduced irrigation water (similar to 37-54% reduction) during the pit hardening stage; (iii) the "confederation RDI" which limited water restriction to the donation of the Guadalquivir hydrographic confederation (similar to 72% reduction); and, (iv) the "confederation SDI", similar water restriction (similar to 72%) but dying the whole tree cycle. In general, the reduction in the irrigation water caused no negative effects on the studied parameters. However, the total phenolic content (TPC) was increased when the deficit irrigation was applied. Fatty acid profile showed changes with respect to the control, increasing oleic acid and the total content of monounsaturated fatty acids (MUFA). For the volatile compound profile, reducing water intake caused changes in mayor volatile compound (trans-2-hexenal), related with green flavors. The application of deficit irrigation treatments increased the value obtained in the fruity parameter with respect to the control. On the other hand, irrigation deficit treatments did not generate changes in the olive oil yield.