In order to investigate the effects of irrigation water quantities (1200, 1600, and 2000 m³/fad.) and spraying with some materials (Trehalose at 1000 ppm, Potassium silicate at 2000 ppm, and proline amino acid at 500 ppm and their interactions on growth, yield, water use efficiency, and tuber quality of potato plants, a field experiment was conducted in a private farm at Meet Faris village, Dekarns, Dakhlia Governorate, Egypt  Spunta cultivar   under  a clay soil environment in summer plantation. Under clay soil conditions and using drip irrigation system during summer plantation, irrigation potato plants at 1600 m³/fad. and spraying with trehalose at 1000 ppm increased shoot dry weight / plant, average tuber weight, average tuber number/ plant, yield / plant and total yield /fad., water use efficiency, also the irrigation of the same level and spraying with potassium silicate at 2000 ppm increased tuber quality (specific gravity, dry matter (%) and starch content). In this context, the interaction treatment between irrigation at a rate of 1600 m³/faddan and foliar spraying with trehalose at a concentration of 1000 ppm recorded a relative increase in the total yield of 22.42% and a saving of 20% of irrigation water compared to the irrigation treatment at a rate of 2000 m³/fad. only (average of the two seasons).