Abstract:
In the conditions of climate change, the selection and adjustment of crop cultivation systems in the moisture deficit zone and the management of risky agriculture to ensure the profitability of production remain an urgent issues. In particular, the Steppe of Ukraine is a zone of increased risk for agricultural production, which is associated with difficult climatic conditions characterized by droughts and low rainfall. An effective measure to ensure stable harvests is the use of growth-regulating biologicalpreparations. Therefore, the purpose of the research was to establish the regularities of the influence of growth-regulating biological preparations on the formation of productivity and the economic efficiency of sunflower cultivation in the zone of riskyagriculture. The study was conducted in 2021–2022 in the Mykolaiv region of Ukraine. A three-factor field experiment was set up to study the influence of various biological preparations (Helafit Combi, Organic Balance, and Biocomplex-BTU) and plant stand density (30, 40, and 50 thousand pcs/ha) on the productivity of sunflower hybrids Vyrii, Yarylo, Blysk, Yaskravyi, and Epikur. It was found that the hybrids Yarylo, Epikur, and Yaskravyi had considerably lower levels of productivity. However, foliar fertilization had a positive effect and contributed to an increase in their productivity. A low level of productivity in 2022 (1.51 t/ha) was observed in the hybrid Epikur under the plant density of 30 thousand pcs/ha. The results of the field experiments allowed establishing that foliar fertilization with different biological preparations is an efficient and effective method for improving plant growth conditions, and can increase the level of agrocenosis genetic potential realization. It was found that the hybrid Vyrii with a seeding rate of 40 thousand pcs/ha and plant treatment with the biological preparation Helafit Combi is the most economically efficient hybrid, with a profitability of 25.59%, and a net profit of $127.20 per ha.
