The Effects of Drought Stress on Growth, Yield and Fruit Quality of Pomegranate (Punica granatum L.) cv. Rababe Niriz Under Dry Climate Condition

Pomegranate (Punica granatum L.) is one of the most important horticultural crops in Iran that it is mostly grown in arid and semiarid regions. Due to water resources limiting in these areas, trees are always under drought stress. For evaluation of the effects of drought stress on growth, yield and fruit quality of pomegranate, this research was carried out in Agricultural and Natural Resources Research Center of Yazd located in dry climate. The irrigation treatments included100% of field capacity (no stress), 75% of field capacity (moderate stress) and 50% of field capacity (high stress) performed in randomize complete block design with four replications and nine trees per each plot. The results showed that pomegranate trees applied several mechanisms for drought resistance such as increasing cell turgid by accumulation of soluble sugars and proline, increasing water potential for more water absorption from soil, chlorophyll and carotenoid pigments preserved by control of leaf relative water content (RWC), reducing leaf area and reducing leaf area specific. Effect of drought stress on yield and fruit quality was higher than the growth characteristics. Drought stress reduced yield, fruit size and the amount of fruit components such as aril, seed, peel and juice. Drought stress increased fruit total soluble solid (TSS), titrtable acidity (TA) and reduced pH. Because of suitable vegetative conditions, good yield performance and improved quality of fruits, scheduling of irrigation based on 75% of soil moisture during the growing season with using of Babler irrigation systems in pomegranate orchards can be recommended based on the results of this study.