Effects of Deficit Irrigation Strategies on Peach Trees Grown in the Desert of Western Nile Delta of Egypt

  Field experiments were conducted in 2011 and 2012 to evaluate the responses of two-year-old peach trees Prunus persica (L.) Batsch cv. early swelling to regulated deficit irrigation (RDI) and partial root-zone drying (PRD) strategies. Trees were trained to a Y-shaped high-density system and drip irrigated. Six irrigation treatments were imposed: Irrigation control treatment (C = full irrigation) that was scheduled based on climatic data according to the crop water balance technique. The RDI treatments consisted of two percentage levels of RDI­-75 and RDI-50, which received 75% and 50% of the irrigation control treatment, respectively. The PRD treatments consisted of three percentage levels of PRD-100, PRD-75, and PRD-50 that received 100%, 75%, and 50% of the irrigation control treatment, respectively. The dripper lines of PRD treatments were worked alternately every seven days. Replicates were assigned for each treatment using a completely randomised block design. Treatments were initiated at the pit hardening stage and continued until harvesting. The effects of the irrigation treatments on tree water use efficiency, physiological responses of leaves and fruits using the electron microscope imaging, fruit growth, yield, and fruit quality will be presented.