Crop yield response to water - Cra

Figure 1 Production trends for olives in the principal countries (FAO, 2011).Spain Italy Greece Turkey Tunisia Syria9 0008 000Production (tonne x 1 000)7 0006 0005 0004 0003 0002 0001 0000198519901995200020052009Quality considerationsOf the several categories of olive oils, defined according by the European Union legislation(Reg. EEC 2568/91, UE 702/07 and 640/08), and widely accepted internationally, the conceptof quality only pertains to virgin olive oil (VOO), the main product of the olive industry.In order to qualify as VOO, it is required that oils satisfy analytical parameters and betested and approved for their sensory characteristics by a panel of experts. Moreover, thecurrent perception of quality is mainly based on the sensory and health-related properties,which are closely related to the concentration and composition of the phenolic and volatilefractions, respectively. Oleic acid is the most abundant fatty acid followed by palmiticacid, linoleic acid and others that do not exceed 2 percent of fatty acid composition.Fatty acid composition is cultivar dependent and changes with climatic conditions andprogression of ripening. The ratio between mono-unsaturated and poly-unsaturatedfatty acids first increases, then it reaches a maximum and then decreases in overripe fruit.The concentration of phenolic compounds in the fruit, and consequently in the oil, is alsocultivar dependent and reaches a maximum at the beginning of ripening, when the skin(epicarp) is still partially green, to decline sharply in overripe fruit. Qualitative features oftable olives are similar to those of other stone fruit used for fresh consumption and includefruit size, pulp-to-pit ratio, pulp firmness, colour and soluble carbohydrate concentration.Most of the world's olive area is composed of the two systems described above. However, inthe last 15 years very high density, hedgerow type, olive orchards (from 1 000 to 2 000 tree ha)have been developed to further reduce harvesting costs using over-the tree harvestingmachines. Because of the higher ET c demand of the dense canopies and the low soil volumeavailable for each tree, irrigation is needed. Average yields can be quite high (5-15 tonne/ha)Olive 301