Potato cultivation is quite demanding and adequate fertilization is a key factor for maximizing yield and producing tubers of high quality. So, two variety of potato (Sponta and Lady Rosita) were used to evaluate its response to foliar application of two sources of potassium under organic fertilization during the two successive winter seasons of 2020/2021 and 2021/2022 at privet farm at Nabarouh city, El-Dakahlia Governorate under open field conditions. For this purpose, the experiment was laid out in split-split plot design with three replications having two variety of potato were arranged as main plot, two type of compost (plant and animal) were assigned at random in sub-plot, whereas three sources of potassium foliar application (without, potassium silicate and mono potassium phosphate were allocated in the sub-sub–plots.According to the results, Spunta cultivar showed a significant superiority in all vegetative growth, chemical content, and yield as well as tuber quality. Addition of animal organic fertilization achieved the highest value of mentioned parameters. As for the effect of foliar application, potassium silicate results the highest value with the most parameters except P%, K%, and dry matter % during both seasons as well as specific gravity in the second season, which recorded the highest values with foliar application with mono potassium phosphate. This study demonstrated that utilization of animal organic with foliar application with potassium silicate was effective with Spunta cultivar.