THE RESPONSE OF YOUNG POTTED OLIVE PLANTS CV. "ZARD" TO WATER STRESS AND DEFICIT IRRIGATION

Abstract

Olive (Olea europaea L.) is one of the fruit trees in which has resistant to drought conditions such as semi-arid regions of Iran. So, there is high production potential for olive tree in many regions of Iran. Also, suitable and vigorous rooted cuttings are essential for establishing new olive orchards. Obviously, water is one of the important factors affecting plant growth and development, so doing more research is essential on the amount of water on olive tree growth. The aims of this research was to determine the effect of amount of irrigation water on vegetative growth of young olive plants cv. Zard, evaluation of its physiological responses and to determine suitable irrigation regimes for this local important cultivar. A split plot experiment in time was used based on completely randomized design with four replicates. Treatments were 20, 40, 60, 80 and 100% evapotranspiration (ETc). The collected data were analyzed based on means comparison of treatments and various factor interactions were determined. Generally root, leaf and shoot fresh and dry weight, leaf area, leaf number, plant height, shoot number and shoot length showed a good correlation with the amount of applied water. The differences between treatments in various measured characters were significantly different except on shoot number with less than 10 cm length. Plants were received 20 and 40% ETc showed no increase in their vegetative growth. Although, plant growth was increased with the other treatments (60, 80 and 100% ETc), this increase in growth was higher in 80 and 100% ETc treatments. In addition, leaf abscission was occurred in plant were received 20 % ETc. The effect of irrigation regime on vegetative growth was correlated with the time of growing season, so no increase in growth observed in warm summer month of the growing season, although most of growth occurred during the spring and autumn.