Sweet potato is a heat- and water-demanding tropical and subtropical plant. Despite this fact, sweet potato production is increasing in Hungary, facilitated by adaptive varieties and the applied production technology adapted to Hungarian circumstances. Of the limited number of scientific findings obtained by Hungarian researchers, there is no quality analysis data related to the quality of the fresh tuber. In 2018, an accurate field experiment was established in the Demonstration Field of the Faculty of Agricultural and Food Sciences and Environmental Management of the University of Debrecen on calcareous chernozem soil. Three varieties (Ásotthalmi 12, Norangel, Emmur) were involved in the experiment, using different planting methods (plan and ridge planting) and row spacings (1.0 m and 0.75 m). The chemical composition of the fresh tubers at the time of harvesting was fundamentally affected by the shorter vegetation period in the temperate zone. The following content ranges were observed in the examined varieties: dry matter: 16–22%, starch: 9–14%, sugar: 1.0–3.1%, protein: 1.5–1.9%. Significant differences were found in the dry matter, starch and sugar content of the examined varieties, while there were no significant differences in terms of protein content. The planting method and row spacing had a significant effect only on sugar content, while there were no significant differences in dry matter, starch and protein content.

Keywords: sweet potato, variety, planting method, row spacing, chemical composition