The article presents the results of the research, aimed at studying the influence of doses and methods of fertilizer application and mass of planting material on the formation of the yield, seed productivity and yield structure of potato tubers in conditions of Vinnytsia region. As a result of the researches carried out by us during 2019-2021 it was established that the yield and yield of seed potatoes change depending on a dose and a way of application of fertilizers, weight of garden tubers and variety features. The highest indicators of structure of a crop yield and yield were received on the variant of experience, where on a background of action of the half-digested manure brought under the precursor and phosphorus-potassium fertilizer under the basic potato processing were brought into rows (locally) Nitroammophoska (N45Р45К45). At the same time, the number of tubers under a bush increased from 9.0 to 9.5 pieces and the average weight of tubers from 78.1 to 79.5 g, the yield increased from 38.3 to 41.1 t / ha with increased fraction of seed tubers . At intensification of potato growing the highest rates due to varietal peculiarities of Granada variety tubers yield, the size of which on the greatest transverse diameter of 28-60 mm were obtained on the experiment variant, where on the background of half-digested manure introduced under the predecessor and phosphate-potassium fertilizer under potato, into rows (locally) Nitroammophoska (N45Р45К45). At the same time, the share of tubers of this fraction varied depending on the weight of planting material from 44.9 to 54.6%. On average over three years, the highest yield of tubers grade Granada received on the experiment variant, where on the background of the action of semi-digested manure and phosphate-potassium fertilizer made into rows (locally) Nitroammophoska (N45Р45К45) fraction ˃60 mm - 41, 1 t/ha, which is 32.6% higher than the control (no fertilizer) and 1.5 t / ha more compared to the yield obtained with the same dose and method of fertilization, but with a fraction of garden tubers 28-60 mm. However, when pointing out the yield gains from planting large tubers, it is necessary to mention the cost of planting material. That is, the difference in planting material expenditure between the best two potato varieties in the experiment, the Granada, was 1.85 t/ha. Consequently, the expenditure of planting material was greater than the yield increase we achieved. A similar pattern was obtained for the early maturing potato variety Laperla and the medium maturing variety Memphis. The important indicator of seed productivity of potatoes is multiplication factor, which changed depending on fertilizer, mass of garden tubers and variety features. The highest values of the reproduction factor as for quantitative as for mass value were observed in the variety Granada, on the experiment variant, where on the background of the action of half-decomposed manure introduced under the predecessor and phosphate-potassium fertilizer under potatoes, introduced into rows (locally) Nitroammophoska (N45Р45К45). At the same time the multiplication factor by the quantitative value varied from 8.3 to 8.7 and by the mass value varied from 7.4 for planting tubers of largest fraction to 17.8 for planting tubers of smallest fraction. It was proved that only at planting by fraction of seed tubers of 28-60 mm the reproduction coefficients both on quantitative and mass value were maximally approached to each other and made 8,5 and 10,7 This points out to optimum ratio of seed material reproduction just at planting by weight of planting tubers of this fraction.
