An investigation concerning potato crop was carried out during the two successive summer seasons of 2015-2016 and 2016-2017 at a newly reclaimed area, at EL-Nubariya city south of Alexandria governorate, Egypt. The experiments were designed to study the efficiency of the film –forming antitranspirant (folicote) concentration (15%(v/v)) or/and soil conditioner (farmyard manure) of the rate 20m3/fed., on optimization of irrigation water in low-water supplx areas. Three irrigation rates were applied; 2100m3/fed. (Common rate), 1575m3/fed, and 1050m3/fed to investigate the effects of water deficiency on some important economic traits of potato crop. The results showed that irrigation at the rate of (2100m3/fed.) only, or addition of farmyard manure or, spray folicote or, mix of folicote spraying and farmyard manure recorded the maximum values of plant height, shoot number, no of tuber yield /plant, weight of marketable tuber / (gm./ plant), weight of total tuber yield / (ton/fed.), dry matter(%) and starch content showed no significant differences between them and treatment of irrigation quantity (1575m3/fed.) with farmyard manure soil application or mix of folicote spraying and farmyard manure soil application in the two seasons. The interaction between irrigation water quantities and antitiranspirant or/and soil conditioner was insignificant regarding total sugars and reducing sugar with one except reducing sugar in2017 season. While, the interaction between irrigation at (1575m3/fed.) with farmyard manure or mix of folicote spraying and Farmyard manure, soil application, gave the highest value of water use efficiency in the two seasons.