PRODUCTIVITY OF SEED POTATOES DURING SUMMER PLANTING OF FRESHLY HARVESTED TUBERS IN THE CONDITIONS OF THE SOUTH OF UKRAINE

Abstract

The purpose of research. Determine the optimal level of mineral nutrition with local application of complex fertilizers in combination with the density of planting tubers on the productivity of the early Kobza cultivar in summer planting with freshly harvested tubers. Materials and methods of research. Field studies were performed on irrigated lands of the Institute of Irrigated Agriculture of NAAS in the area of the Ingulets irrigation system. The following factors were studied: A – planting density – 42.8, 57.1 and 71.4 thousand units/ha, B – feeding background: control (without fertilizers), N30P30K30, N60P60K60, N90P90K90, N120P120K120. Agricultural techniques in the experiment, in addition to the studied factors, are generally accepted for irrigated lands of southern Ukraine. Research results. When increasing the dose of fertilizers to 90 kg/ha NPK, there was a tendency to form more tubers in one bush with 4.8 pcs. up to 5.2 pcs/bush, or 7.7 %. With a further increase in the feeding background from 90 to 120 kg/ha NPK, the number of tubers remained unchanged. With an increase in planting density, the weight of tubers decreased, on average, by 9.8 %, from 101.5 g in the variant with the lowest (42.8 thousand pcs/ha) to 91.6 g with the highest planting density (71,4 thousand pcs/ha). The influence of feeding background for most performance indicators, according to the results of correlation-regression analysis, was more significant than the planting density. Conclusion. Upon receipt of seed potatoes for summer planting of freshly harvested tubers, the highest yield of tubers was obtained when applying the norm of planting potatoes of Kobza variety in the summer 57.1 and 71.4 thousand pcs/ha and applying N90P90K90 – respectively 20.29 and 20.33 tons/ha. But the most economically feasible is the combination of the main elements of cultivation: planting with a density of 42.8 thousand pcs/ha and local application of mineral fertilizers at a dose of N90P90K90. The yield was 19.99 t/ha, conditional net profit – 115.98 thousand UAH/ha, unit cost – 3.62 thousand UAH/t, profitability – 176 %.