The efficiency of foliar spray with potassium sulphate, potassium silicate, calcium chloride and calcium citrate gel formula was evaluated in controlling early blight disease (caused by Alternaria solani), improving growth and yield quality of potato (cv. Lady Rosetta). A field experiment was performed during two successive seasons, 2018/2019 and 2019/2020. Foliar applications of potassium and calcium compounds were compared to Copperal Max (8 % copper as a positive control) and water as a control treatment. All treatments were sprayed twice on the plants at 45 and 60 days post-planting. The results proved that all foliar spraying treatments significantly decreased the disease incidence and severity of early blight, improved vegetative growth parameters and nutrients content (N, P and K) of potato plants as well as increased yield and tuber quality of potato compared with untreated plants. In this respect, the lowest disease severity was achieved by Copperal Max (9 and 11.05%) followed by potassium silicate (9.95 and 12.77%) and calcium chloride (9.66 and 12.92%), finally, untreated control recorded the highest disease severity (22.07 and 26.71 %) respectively at both tested seasons. On the other hand, potassium silicate and calcium chloride in gel formula was superior to other treatments in increasing the total and marketable yield of potato tubers, also reducing the weight loss and decay of tubers stored on a shelf. These results suggest that one of the main alternatives to controlling potato early blight is using potassium silicate or calcium chloride.