Effect of nitrogen application on selected nutritional components of potato tubers

In this work the influence of graduated nitrogene fertilizers doses to the soil on starch and vitamin C formation in potato tubers grown in field conditions in locality Veľká Čalomija was studied. The investigated potato cultivar Solara is medium early potato cultivar. The determined average starch content in potato samples ranged in interval 12,426 % - 15,084 %, while the highest starch content was determined in variant 1 (without nitrogen addition to the soil). The starch content in potato tubers was decreased in order: variant 1 (15,084 %) > variant 2 (14,427 %) > variant 3 (14,378 %) > variant 4 (14,023 %) > variant 5 (12,603 %) > variant 6 (12,426 %). The content of C vitamin was increased with the graduated nitrogen doses to the soil only till variant 4 and after that the content of vitamin C was decreased. The average content of C vitamin ranged in interval 3,786 - 6,225 mg.kg-1 of fresh matter