Productivity and economic efficiency of growing sunflower depending on the sowing time and plant density in the Right-Bank Steppe of Ukraine

Abstract

The article covers the results of research on the management of elements of technology and the influence of factors on the productivity of sunflower. The field experiment was conducted in the experimental field of IAS NAAS Kirovohrad region. The level of sunflower productivity is determined by the conditions of water and nutrient regimes of soil. According to the results of research it was established that at the time of sowing reserves of available moisture in 0–100 cm of the soil layer were the largest during the first sowing period and amounted to 178.6 mm. Such moisture reserves create favorable conditions for moistening the seed layer of soil to obtain friendly and full seedlings when sowing in the first – second decade of April. The use of moisture by sowing sunflowers can be regulated by sowing dates to some extent. Shifting sowing dates to earlier ones makes it possible to change the conditions of growth and development of sunflower plants, namely, the plants are better provided with moisture, and it is possible to avoid critical temperature periods of plant development. The high reserves of productive moisture for plants in 0–100 cm soil layer, in crops of Forward, LG 56.32, LG 54.85, LG 55.82 hybrids were for plant density of 60 thousand per hectare, at the first sowing period – in the flowering phase they were 127 mm. The content of nutrients the soil changed both over the years and under the influence of different fertilizer backgrounds. Application of nitrogen, phosphorus, potassium fertilizers in the dose of N40P40K40 and N40P40K40 + by-products of the predecessor allows to increase the content of nutrients available to plants in soil and to increase soil fertility. Due to economic indicators, the optimal time of sunflower sowing for hybrids LG 55.82 and LG 54.85 is warming soil at the depth of seed wrapping up to 5–6 °C, for hybrids Forward and LG 56.32 is warming soil at the depth of seed wrapping up to 9–10 °C, optimal density – 60 thousand/ha. In such conditions, the LG 55.82 hybrid formed the highest yield – 3.85 t/ha, LG 54.85 hybrid – 3.64 t/ha, Forward – 3.09 t/ha, LG 56.32 hybrid – 3.62 t/ha. Key words: sunflower, soil nutrient regime, water regime of soil, yield, profitability, net profit.