Impact of Abiotic Stress-Reducing Cultivation Technologies and Long-Term Storage on the Oxidative Potential of Edible Potato Tubers (<i>Solanum tuberosum</i> L.)

Currently, in the context of the emphasis on introducing a reduction in mineral fertilization and the increase in pressure on sustainable agriculture, magnesium fertilization and the use of biostimulants are becoming an alternative tool to increase the quality of potato tuber yield. This study aimed to assess the impact of potato genotype, cultivation technology, and long-term storage on the susceptibility of tubers to enzymatic browning. Two edible potato varieties were examined: the early ‘Wega’ and the mid-early ‘Soraya’. It was demonstrated that the varieties maintained their characteristic browning susceptibility consistent with their breeding descriptions. The ‘Wega’ variety exhibited decreasing browning susceptibility immediately after harvest; however, after 6 months of storage, its susceptibility significantly increased, exceeding that of the ‘Soraya’ variety. Additionally, the application of magnesium fertilization (90 kg ha⁻¹) and biostimulant treatment (3 L ha⁻¹) most effectively reduced the oxidative potential of the tubers, thereby decreasing browning susceptibility. This is due to a significant change in the concentration of organic acids responsible for enzymatic browning processes. A decrease in the content of chlorogenic acid by 9.4% and 8.4% and an increase in the content of citric and ascorbic acid by 11.1%, 5.3%, and 13.6% were achieved. Storage significantly affected the chemical composition of the tubers. An increase in chlorogenic (7.3%) and citric (5.8%) acids and a decrease in ascorbic (34%) acid content were observed. These changes correlated with the intensification of browning, with the increase in chlorogenic acid and the decrease in ascorbic acid having the greatest influence. The results indicate that the technology based on supplementary fertilization and biostimulation improves the quality of potato raw material without a significant increase in production costs. Further research on varieties with different vegetation lengths and those intended for food processing and starch production is advised.