Determination of the agronomic and physiological characteristics and high temperature tolerances of Gemlik olive saplings which were raised under deficit irrigation conditions

The aim of the present study was to determine the agronomic and physiological effects of deficit irrigation practices on one year-old olive saplings and to determine the changes related to the tolerance of olive saplings to high temperature conditions following these applications. In the experiment, four irrigation treatments were applied: I100: full irrigation, I66: irrigation at the level of 2/3 of the water amount determined for the full irrigation treatment, I33: 1/3 of the water amount determined for the full irrigation treatment, and I0 (dry-no watering) treatment. Measurements of stem diameter, plant height, shoot length, number of leaves, fruit width and length, leaf area were carried out in certain periods. The rolling rates of the leaves and the formation of bottom shoots were evaluated according to the irrigation levels as well. In addition, leaf water content (YOSK), turgor loss (TK), leaf water potential, chlorophyll amount (SPAD) and stomata number, changes in stomatal width and length were investigated. In the last stage of the experiment, high temperature was applied to the olive saplings under controlled conditions after the deficit irrigation for 4 months. High temperature treatments were carried out by two methods as cascade and shock temperature applications. Data showed that irrigation levels significantly affected agronomic and physiological results at p≤0.05. At the same time, it was determined that the effect of irrigation levels was significant at p≤0.05 with regard to high temperature conditions. It was observed that the plants irrigated at I33 level were more tolerant to high temperature applications. As a result of the present research, on evaluation of growth and development parameters, I66 irrigation is recommended for irrigation of "Gemlik" olive saplings.