The world production of oil crops is steadily increasing, which is due to a great number of factors [1]. In particular, high demand in developed countries occurs for economic reasons due to the reorientation of the consumption of animal fats to vegetable ones. The growing demand of the world market for oil crops, in turn, leads to an increase in acreage, production and export of vegetable oils (including sunflower oil) from the Russian Federation. Cultivation of foreign sunflower hybrids that are not sufficiently adapted to domestic soil and climatic conditions and realize their potential, as a rule, only under conditions of technogenic intensification, does not guarantee an increase in yield in the main regions of the country [2]. The productivity of sunflower depends on the quality of seed material, soil fertility, predecessor, weather conditions and the level of agricultural technology [3–6], the study of the elements of which became the purpose of our research.

In 2018–2019 in the Research Institute of Agriculture of Crimea, the effect on the yield and oil content in sunflower seeds of the sowing period and plant density was studied within a two-factor fi eld experiment performed in three repetitions. The objects of research are the Fakel hybrid and the Belochka confectionery variety. Standing density for a hybrid: 30 thousand, 40 thousand, 50 thousand, 60 thousand, 70 thousand, for a variety: 20 thousand, 25 thousand, 30 thousand, 35 thousand, 40 thousand plants/ha Sowing period: I, II and III decades of April. The total area of the plot is 28 m², the accounting area is 14 m². Meteorological conditions in 2018 were characterized by a shortage of precipitation at the beginning of the vegetation season, which led to the formation of low seed yields, and in 2019 the weather favoured the growth and development of sunflower plants, having a positive effect on crop productivity. The hydrothermal index in 2018 was 0.7, in 2019 — 0.8, which, according to Selyaninov, equates to arid conditions. Statistical processing of the obtained results was carried out by the method of two-factor analysis of variance [7, 8].