The influence of selected cultivation on the content of total protein and amino acids in the potato tubers

The aim of study was to determine the effect of selected cultivation operations, such as nitrogenous fertilization (60, 90 kg N/ha), row spacing (62, 82, 102 cm), compaction of soil with wheels of farm aggregates (the numbers of passing 2x, 5x, 8x), on quality changes of two potato varieties (Irga and Ekra). The total protein content in the tubers of the tested potato varieties increased with the increase of the nitrogenous fertilization (90 kg N/ha). Genotype features of the tested potato tubers define the amino acid limiting the protein biological value (CS) to be leucine in Irga variety and isoleucine in Ekra variety. It is also genotype that influences the second limiting amino acid. It is the sum of sulphuric amino acids (Cys + Met) in respect to Irga variety and valine in respect to Ekra variety. The dose of 90 kg N/ha decreases the protein biological value (EAAI) of the tubers of Ekra variety, which is high in starch.