A three-year field experiment was conducted in 2002-04 to evaluate the effects of soil tillage and weed control methods (including herbicides and their mixtures) on the content of polyphenols in edible potato tubers, cv. Wiking. The results obtained indicated that the content of polyphenols in non-peeled and peeled tubers depend on the methods of soil tillage and weeding, as well as on the years of cultivation. The content of polyphenols in the tubers subjected to the initial treatment (peeling) decreased to 7.2-14.9%, compared to the level of polyphenols before peeling.