Abiotic stress factors, especially drought and heat stress, which are becoming more frequent and intense due to climate change, pose significant challenges to potato production. The aim of this research was to examine the effects of different irrigation schemes and foliar treatments – salicylic acid, silicon, hydrogen peroxide, and microelements – on the physiological parameters, yield, and quality characteristics of potatoes under drought conditions. In a field experiment conducted in Sonkád (Hungary) during the 2024 growing season, a medium-late Manitou variety was used. During the study, two irrigation doses and four types of foliar treatments were tested in a split-plot design. Based on the results, full and 50% irrigation significantly increased stomatal conductance, NDVI, leaf area index, and yield. Among the foliar treatments, silicon and hydrogen peroxide had a positive effect on relative chlorophyll content and NDVI, but did not result in a significant increase in yield. Treatments with salicylic acid, microcomplex, silicon, and the total dose significantly increased starch content, while the application of silicon increased the amount of reducing sugar content. The results of the first year of experiments indicate that foliar treatments applied without irrigation can only occasionally mitigate the negative physiological effects of water deficiency, but irrigation is essential to achieve significant improvements in yield and quality. The research may contribute to technological developments aimed at increasing drought tolerance in potato production, but further experiments are needed.