EFFECT OF MINERAL FERTILIZATION ON HARMFUL COMPONENTS IN POTATO TUBERS WITH PURPLE-BLUE FLESH
Background. There are few reports in the literature on the impact of agricultural technology on the content of mineral components in a type of potato, with purple-blue peel and flesh, that is not yet commonly grown in Poland. However, an increasing interest is being shown in these cultivars owing to their high content of healthy substances associated with the colour of the tuber flesh. The aim of this experiment was to determine optimal doses of soil fertilization with basic macronutrients used in potato cultivation and see how they affect the quality composition of potato tubers with purple-blue peel and flesh.
Material and methods. In the first part of the experiment (I), nitrogen was applied as urea fertilizer (46% N) at doses of 40 kg·ha-1, 80 kg·ha-1 and 120 kg·ha-1. In the second part of the experiment (II), potassium was applied as potassium sulphate (50% K) at doses of 120 kg·ha-1, 150 kg·ha-1 and 180 kg·ha-1. Statistical analysis was performed using the one-way analysis of variance (ANOVA) (Statistica 10.0, StatSoft, USA). The Fisher’s LSD test was applied to assess significant differences (P < 0.05) between samples.
Results. The following were determined in potato tubers: content of nitrates, content of total chlorophyll pigments and level of α solanine. The results suggest that optimal doses of fertilizers applied to soil for the cv. Blue Congo potato are: nitrogen 40 kg·ha-1 and potassium 120 kg·ha-1.
Conclusion. At this level of mineral soil fertilization, the lowest content of nitrates was observed. Also, they were optimal doses with regard to total chlorophyll and toxic α solanine.