For potato processing, especially for the production of French fries a
nd chips, tuber contents of reducing sugars are very important, as red
ucing sugars negatively affect product colour and taste. Therefore, re
sults of several experiments are presented showing that among differen
t interactive factors effecting the content of reducing sugars in pota
to tubers the variety is the most important one. Variety-specific gene
tics define the upper and lower limits of possible synthesis of reduci
ng sugars. Within such a pre-determined range the actual content is a
question of weather conditions, site, tuber physiology (maturity) and
storage temperature, these factors being of almost equal importance. T
he influence of fertilization, however, seems to be overrated. The res
ults show that potato growers have only three possibilities to influen
ce the synthesis of reducing sugars: by choice of a suitable variety,
by harvesting mature raw material, and by storing potatoes under optim
um temperature conditions.