This study describes the effects of mechanical harvesting and irrigation on quality in ‘Arbequina’ olive oil ( Olea europaea L.). Irrigation treatments included a control, deficit irrigation (DI) during pit hardening, and subsurface deficit irrigation (SDI). Results showed that mechanical harvesting damaged the olives and reduced olive oil quality by increasing free fatty acids (FFAs) and peroxide value, and by decreasing fruitiness, stability, bitterness, and pungency. DI resulted in increased fruit dry weight and oil content, which could be explained by their reduced crop load (9.3% of crop reduction for DI and 23.9% for SDI). DI did not affect olive oil characteristics, whereas SDI increased stability, fruitiness, and bitterness, and decreased polyunsaturated fatty acid (PUFAs). In conclusion, mechanical harvesting tended to damage the fruit, resulting in lower quality olive oil, the DI strategy neither affected fruit nor olive oil characteristics, whereas the SDI strategy positively affected oil quality when greater water restrictions were applied.

ISHS International Symposium on Foliar Nutrition of Perennial Fruit Plants PREHARVEST CALCIUM SPRAYS AND FRUIT CALCIUM ABSORPTION IN GOLDEN APPLES

Regulated deficit irrigation in super-high-density (SHD) olive orchards is a well-known strategy to save water and control plant vigor, without decreasing fruit or oil yield. As there is controversial information about its influence on virgin olive oil quality, a trial was conducted in five SHD olive orchards of Arbequina cultivar in different locations of central, east, north and northeast Spain under full irrigation (FI) and regulated deficit irrigation (RDI) treatments. RDI applied during phase II of fruit growing (40% of total needs) saves more than 20% of water on average, without reductions in olive fruit or extra virgin olive oil (EVOO) yield. No threshold of 3.5 MPa of stem water potential was crossed in any case. RDI modified sterols and the fatty acid profile of EVOOs but not phenols, quality parameters, or the sensory profile. Latitude, altitude, and yearly rainfall have a big impact on some compounds such as campesterol, oleuropein, or margaroleic or linolenic acids.

Calcium foliar applications are known to effectively enhance peach quality; however, the optimal implementation strategy regarding fruit developmental stages and cultivars remains unclear. In this study, three different moments of fruit Ca applications in peach and nectarine are tested: Early season, Mid-season, and Late season. For this aim, the ⁴⁴Ca isotope was used as a tracer, enabling the quantification and location of the Ca derived from the foliar fertilizer. Stone, flesh, and skin ⁴⁴Ca enrichment was separately analyzed at harvest. The results indicate that Ca absorption in the fruits from external CaCl₂ applications was influenced by the timing of the application during fruit development, with Late-season applications proving to be the most effective in increasing the Ca content in the fruit, corresponding with a higher fruit size at the application moment. Nevertheless, no differences in the absorption efficiency were found between the three timings of the application. Furthermore, the Ca from the foliar fertilizer in the fruit predominately remained in the flesh, followed by the skin. The Ca derived from the foliar fertilizer reached the stone in all of the experimental situations, but the Early- and Mid-season applications resulted in the highest amount of Ca derived from the fertilizer in this part of the fruit. Interestingly, the peach exhibited a higher Ca absorption efficiency compared to the nectarine, likely due to the presence of trichomes that retain the foliar fertilizer on the fruit surface. In conclusion, the Ca absorption and distribution in peaches depends on the cultivar and timing of the Ca application.