Background. The aim of the study was to determine the effect of selected methods of weed control on the content of total and true protein in tubers of three cultivars of edible potato. Material and methods. The two-way field experiment was carried out in a split-plot design in three replications. The studied factors included: I – three potato cultivars: Cekin, Satina and Tajfun. II – five methods of weed control: (1) mechanical treatment – control plot, (2) mechanical treatment + herbicide Command 480 EC at a rate of 0.2 dm³·ha^-1, (3) Mechanical treatment + herbicidal combination Command 480 EC at a rate of 0.2 dm³·ha^-1 + Afalon Dyspersyjny 450 SC at rate of 1.0 dm³·ha^-1, (4) Mechanical treatment + herbicide Stomp 400 SC at a rate of 3.5 dm³·ha^-1, (5) mechanical treatment + herbicidal combination Stomp 400 SC at rate of 3.5 dm³·ha^-1 + Afalon Dyspersyjny 450SC at a rate of 1.0 dm³·ha^-1. Results. The highest contents of total and true protein as compared with the control plot were obtained on plots where the herbicidal combination Stomp 400 SC + Afalon Dyspersyjny 450 SC was used and the herbicide Stomp 400 SC by itself was used. The research results indicated that cv. Satina was characterized by the highest concentration of total protein, on average 12.98% d.m., and of true protein with the average being 8.60% d.m, while cv. Tajfun had the lowest content of the discussed nutrients, 12.04 and 8.08% respectively, of the dry weight of tubers. Weather conditions over the years of research varied the content of both total and true protein. The highest content of total and true protein was found in tubers in 2009, which was characterized by the most optimal rainfall total and air temperature for potato development experienced during our study. Conclusion. Herbicides applied in the experiment as well as weather conditions in particular years of research contributed to a diversified content of total and true protein in potato tubers. The content of the discussed component was also determined by varieties cultivated in the experiment.

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