Pistachio (Pistacia vera L.) is a drought-resistant tree of subtropical deserts, that has developed the ability to satisfy its high moisture requirements due to an extremely developed “two-story” deep root system. This is a heat-loving and heat- resistant crop, the xeromorphic and heliophilic structure of its leaves creates an exceptionally high resistance of its assimilation apparatus to high air temperatures (up to 480C). When the soil dries out from spring to autumn, the suction force of the pistachio roots increases with a simultaneous increase in this indicator (up to 87 atmospheres) and osmotic pressure in the cell sap (up to 70 atmospheres) in the leaves, which helps the tree find assimilable moisture in the soil when there is a pronounced deficiency of it, thereby ensuring high transpiration and optimal water content in the leaves to maintain their turgor and reduce heat.