The effect of cultivar on selected quantitative and qualitative parameters of sweet potatoes (Ipomoea batatas L.) grown in Slovak republic

The sweet potato (Ipomoea batatas L.) is less-known vegetable species in Slovak Republic. It is known for sweet taste and various possibilities of use in gastronomy. In this study, the effect of cultivar on the important quantitative (yield of marketable tubers per plant, average weight of marketable tubers, yield of marketable tubers per hectare, share of marketable tubers) and qualitative (antioxidant activity, polyphenol content) parameters of sweet potatoes grown in Slovak Republic was tested. The highest yield (1964.16 g/plant; 54.56 t/ha) and average weight (446.18 g) of marketable tubers (> 150 g) were found in white sweet potato cultivar 'Visnjica white'. The highest ratio of marketable tubers was found in orange cultivar 'Beauregard' (87.17%). The purple cultivar 'Visnjica purple' was characterized by significantly lower values of all quantitative parameters of sweet potatoes. On the contrary, the highest antioxidant activity (61.07% DPPH; DPPH: 2,2-Diphenyl-1-picrylhydrazyl) and polyphenol content (4506.90 mg/kg dry weight) were found just in purple cultivar 'Visnjica purple'. The significantly higher values of both parameters, compared to other cultivars, are caused by abundance of anthocyanins. Results of this study revealed that sweet potato is expressed by good yield potential, together with its quality, in conditions of Slovak republic, or Middle Europe in generally.