Effect of nitrogen and potassium fertilization on mineral and amino acid content of colored flesh potato cultivar Blue Congo

ABSTRACT

The purpose of this study was to determine optimum rates of soil dressing with nitrogen (N) and potassium (K) fertilization in the cultivation of potato with purple–blue peel and flesh, affecting the qualitative composition of tubers of a less known potato cultivar called Blue Congo.

The experimental results proved that the optimum rates of fertilizers applied to soil for the cultivar Blue Congo are 80 kg N ha⁻¹ and 150 kg K ha⁻¹. Application of 120 kg N ha⁻¹ caused a decrease in the content of all macro- and micro-nutrients. In contrast, the content of all macronutrients was observed to increase up to the rate of 150 kg K ha⁻¹.

Micronutrients responded to the increase in the K rate in different ways. No effect of the differentiated rates of K was noted in the case of iron. Vitamin C responded by its lower content to the increased rates of both N and K. It was determined that isoleucine was the limiting amino acid for the cv. Blue Congo potato. The highest level of isoleucine was found at the N rate of 80 kg ha⁻¹.

KEYWORDS:

• chemical score
• exogenous amino acid index
• mineral components
• potato cv. Blue Congo