Peculiarities of growth and development of sunflower hybrids when using LCS in the conditions of forest-steppe of Russia

Individual features of growth, development and dry matter accumulation by sunflower hybrids of one maturity group on typical, medium-humus, medium-loamy chernozem were studied. The research was carried out in a link of grain-plowing crop rotation on the lands of farm S.E. Nekipelov Pristensky district of Kursk region in different hydrothermal conditions in 2020–2022. The object of the study were sunflower hybrids (Sumico-Syngenta, P63LE10-Pioneer and Elion-Galaktika), sown to a depth of 4–5 cm when the soil was heated to 10 °C in the amount of 60 thousand pcs/ha of germinating seeds. The work was carried out in the technology of yield planning 40 c/ha, with the introduction of liquid complex fertilizers (HCS NР 11:37) before sowing in the amount of 50, 100 and 150 l/ha per depth 5, 10 and 15 cm. In the experiment, the traditional technology of preparing the soil for salting with the regulation of the number of the weed component by Express Sun technology was used. Due to the increased growth energy of the hybrids under consideration, the height of plants varies according to the phases of development and maturation in the studied variants reached 177–191 cm, which is 4.7–6.5% higher than the control values. The mass of plants in the sunflower agrocenosis increased in the Sumiko hybrid by 13.2%, P63LE10 by 11.1%, Elion by 12.5%. The plants of the hybrid Elion accumulate more dry matter in the aboveground mass. The use of HCS at a maximum dose of 150 l/ha when applied to a depth of 15 cm contributed to an increase in the accumulation of dry matter by the maturation phase in the plant biomass of the Sumiko hybrid by 304.3 g/m², the P63LE10 hybrid by 177.7 g/m², the Elion hybrid by 354.0 g/m², or, respectively, by 34.7%, 17.2% and 33.7% relative to the control.