Effect of Drought Stress on Yield Quality, Water Productivity and Profit Net of Potato Crop under surface and subsurface drip irrigation systems

Agriculture face challenges from water allocation and complications arising out of the climatic changes. Field experiments were conducted at Demo Farm, Faculty of Agriculture, Fayoum University. Potato seeds were planted in two seasons (2020 and 2021). The treatments are three deficit irrigations (DI) {I1, I2 and I3 (100, 80 and 60% of ETc)}, two partial root zone drying (PRD) practices (single and double laterals), and three buried depth laterals {surface, and subsurface drip irrigation (SDI) with depths of 15 and 30 cm}. Tuber size and its physical properties, water productivity (WP), and profit net (PN) were determined. Results indicated the greater grade size of tubers was at 30-60 mm. At size 30-60 mm, the highest values of tuber yield, real density and PN were 31.942 t/ha, 1.087 g/cm3, and 274906 L.E./ha, respectively, and they were recorded at I1 under PRD and buried depth of 15 cm. The highest value of WP was 13.82 kg/m3, and it was recorded with I3, PRD under SDI with buried depth of 15 cm. When irrigation water applied (IWA) decreased by 20% and 40%, the potato yield decreased by 8.65% and 29.57%, respectively. When irrigation water is abundant, it could be using treatment I1, PRD irrigation and SDI with buried depths of 15 cm to reach the highly significant yield and PN. While, under shortage of water resources, using treatment I2, PRD irrigation, and SDI with buried depth of 15 cm to save 20% of IWA with a decrease of 8% in the potato yield.