Plant and Soil Science

The cultivation of high oleic sunflower hybrids is very promising as sunflower is highly competitive on the international market and has a growing demand for oil as the main product of its processing. Despite the significance of sunflower as one of Ukraine's traditional crops, its cultivation technology still has many unresolved issues. Among the elements of cultivation technology aimed at increasing crop yields, research with high-oleic hybrids is of particular importance, as it requires studying the level of mineral nutrition and the need for sulfur application, considering their impact on the oleic acid content. The purpose of the study is to determine the effect of sulfur at different rates of mineral fertilisers on the formation of productivity of high-oleic sunflower plants on typical low-humus chernozems of the Right-Bank Forest-Steppe of Ukraine. The research programme envisaged the establishment of a field trial in 2015-2017. The research was conducted in the form of a two-factor field experiment. The experimental program provides for the study of the following factors: factor A – mineral fertiliser application rates, factor B – sulfur application. The study was conducted using generally accepted methods for scientific research in crop production. The study revealed that the maximum amount of dry matter was accumulated in the variants with the introduction of N₉₀R₇₅K₁₃₅+S₃₀ and N₁₂₀R₁₀₀K₁₈₀+S₃₀. The addition of sulfur increases the dry matter yield from 5.69% to 9.27%. The highest yield of sunflower seeds is formed by applying N₉₀R₇₅K₁₃₅+S₃₀ -4.12 t/ha. A further increase in the rate of application of mineral fertilisers does not lead to a significant increase in yield. The introduction of S₃₀ in combination with N₉₀R₇₅K₁₃₅ allows increasing the yield of sunflower seeds by 0.35 t/ha or 9.28%. The correlation and regression analysis of the obtained research results shows a close correlation between the accumulation of dry matter mass in BBCH55-57 and BBCH 65-67 and the level of yield (respectively r = 0.917 and r = 0.972). The highest fat content in seeds (49.7%) with the highest oleic acid content (88.5%) and the maximum oil yield (2.05 t/ha) is provided by the cultivation of the ES Romantic hybrid with the introduction of N₉₀R₇₅K₁₃₅+S₃₀

oilseeds, hybrids, mineral nutrition, mineral fertiliser application rates, dry matter, yield