Experiment results proved the increase of general merchantability of tubers by 88,1 – 90,8 % against 86,3% in control plot. The share of middle fraction of tubers increased by 85,6 % and the share of small fraction decreased by 9,2% due to the growth of the quantity of tubers, not their weights, so the starch content was maintained.
Large fraction share was 5,5 %, seed fraction – 85,6 %, small fraction – 9,2 %. Tubers seed fraction share was maximal as in terms of tubers weights (85,6 %) as in tubers quantity per 1 potato plant (11,8 tubers/plant). Dry matter yield, starch and vitamin C: 45,6 hwt/ha dry matter, 31,2 hwt/ha starch and 4,3 kg/ha vitamin C.