Apparently the olive tree was domesticated in the eastern Mediterranean where it was grown already 5,500 years ago. This species is perfectly adapted to the climate of the region, so that it was grown on drylands for thousands of years.
This adaptation is thanks to the tree’s ability to explore large volumes of soil, with its roots reaching dozens of meters into the soil and growing horizontally far beyond its canopy.
Moreover, the leaves have anatomical and physiological mechanisms to reduce the loss of water by transpiration, they are small, thick and their few stomata are to be found in small hollows on their lower side, protected by hairs that maintain the humidity of the air surrounding them.
Even so, when olive trees undergo water stress, the fruit does not develop fully and the water in its tissues migrates to other plant organs, so that it remains small in size and shriveled.
The profitability of the orchard can be increased considerably and the years of alternative bearing reduced with a well managed fertigation program.