EN
Three potato cultivars, Adam (early), Rudawa (late) and Skawa (late), were grown in a threeyear experiment in Bałcyny. The foliar fertilizers ADOB Mn, Basfoliar 12-4-6 and Solubor DF were applied alone and in combinations. The quantitative and qualitative composition of fungal populations colonizing potato leaves was determined. Yeast-like fungi were most frequently isolated from potato leaves of all cultivars (46.4% to 89.4% of total fungi). Pathogens represented by Alternaria alternata, Borytis cinerea, Helminthosporium solani and species of the Fusarium genus were isolated from potato leaves. Foliar application of fertilizers affected the occurence of pathogens; larger number of fungi isolates was obtained in the control treatment without foliar fertilization, than in the treatments with foliar fertilization.