IMPACT OF DEFICIENT IRRIGATION AND COMPOST ADDITION ON WATER PRODUCTIVITY, GROWTH AND YIELD OF POTATOES SOLANUM TUBEROSUM L. ALBAIDA CV

A pots experiment was carried out in Khanaqin District -Diyala Governorate in 2024 spring season in clay loamy texture soil to study the effect of deficient irrigation and compost addition on water productivity, growth and yield of potatoes.The first factor was adding compost at three levels, 0, 0.2, and 0.5% of the weight of the soil.The second factor included deficient irrigation treatments (full irrigation without cutting, two cutting irrigations during vegetative growth stage, three cutting irrigations at tubers initiation stage, and four cutting irrigations at tubers formation stage) and the cutting of irrigation was non-consecutively.The study treatments were conducted according to randomized complete block design (RCBD), with three replications.Potato tubers of the Aldaida variety were planted, and irrigation was scheduled based on the American evapotranspiration basin, class A. The results showed that the addition of compost with 0.5 % increased significantly all studied parameters (plant height, leaf area, dry weight, total yield, and water use efficiency).The deficient irrigation treatments led to a significant reduction in the studied parameters compared to the full irrigation treatment, the values reached (49.650 cm plant-1, 78.850 dm2 plant-1, 136.850 gm plant-1, 39.700 Mg ha-1 and 31.971kg m-3).Interaction treatment of adding compost at 0.5% rate and full irrigation led to an improvement in most studied parameters, as the values reached (55.8 cm plant-1, 85.4 dm2 plant-1, 147.2 gm plant-1, 45.5 Mg ha-1, and 34.377 kg m-3) for (plant height, leaf area, dry weight, total yield, and water use efficiency), respectively.The depth of water added to the full irrigation treatments was 421.5 mm season-1, while the lowest value of the depth of water added was 362.3 mm season-1 when cutting treatments with four irrigations during the tuber formation stage.