Although the olive is traditionally grown in the Meditteranean basin area under arrid conditions with very low precipitations during phenophases that are important for the generation of yield/crop, and the need for the introduction of irrigation measures is increasingly expressed particularly in the karst landscape of coastal and island areas. The distinctivness of cultivated karst soil lays in its petrousness, lack of moisture and low water capacity. Rational use of water is of utmost importance. This thesis determined the necessity for irrigation water and the arrangement of irrigation of olives in the vegetation season for agroecological conditions of Jadrtovac in the average wet and average dry year. The Cropwat model was used to calculate the need of olives for water, taking into account soil characteristics, meteorological indicators and olive characteristics. Morphological measurements of tree growth and development parameters and olive grove were performed during winter storms, during vegetation and at the end of vegetation and measurement of fruits. Treatments 50 % ET and 75 % ET proved to be the best during morphological measurements and measurements of wealth compared to contol treatment (without irrigation) which did not achieve positive results. After processing the fruits, all olive oil samples were classified into the category of extra virgin olive oils according to the quality parameters.