The research results were based on a field experiment carried out in the years 2000–2001 on soil of very good rye complex at the Experimental Station in Zawady. The experimental factors were 5 weed control methods and 3 cultivars of potato. The estimation of darkening
of raw tubers flesh was performed done after 4 hours, and of cooked tubers flesh after 4 and 24 hours after cooking, based on coloured tables of Danish 9-degress scale. Darkening of raw tubers significantly depended on the cultivar characteristics and weed control methods and the darkening of cooked tubers flesh depended on the weather conditions in vegetation periods as well as.