Yacon [Smallanthus sonchifolius (Poeppig & Endlicher) H. Robinson]: a new crop in the Central Europe

Yacon [Smallanthus sonchifolius (Poeppig Endlicher) H. Robinson, Asteraceae] is a tuber plant originated in Andes. In contrast to other root crops, which store the carbohydrates in the form of starch, yacon cumulates the carbohydrates in the form of fructooligosaccharides. They are not metabolized in the digestive tract and thus the consumption of yacon does not increase the level of glucose in the blood. This is one of the reasons why yacon is considered to be nourishment with a high potential for diabetics and overweight and obese people. As yacon leaves contain up to 25% of proteins in dry mass, it can be also used as forage. In the years 2001-2005, the meteorological conditions in the Czech Republic and their influence on biomass production (yield of root tubers, rhizomes and aboveground parts) were studied on yacon landraces originated in Bolivia, Ecuador, Germany and New Zealand. Yields of root tubers reached up to 35 t/ha, rhizomes up to 33 t/ha, and aboveground parts up to 54 t/ha. In terms of root tubers formation, the landrace with the highest yield (29.18 t/ha) was the one coming from New Zealand; in terms of overall biomass production, the landrace with the highest yield (92 t/ha) originated in Bolivia. The crucial factor for the root tubers yields is the precipitation; the length of vegetation period and the temperature are secondary.