CHANGES IN BIOMETRIC PARAMETERS AND PRODUCTIVITY OF DIFFERENT SUNFLOWER HYBRIDS DEPENDING ON THE SEEDING RATE

The aim of the study was to investigate the reaction of promising sunflower hybrids ‘Aris’, ‘Klip’ and ‘Fogor’ selected by Federal Scientific Centre V.S. Pustovoit Russian Research Institute of Oil Crops to changes in the seeding rate (40, 60 (control) and 80 thousand units/ha) on common chernozem of the Western Ciscaucasia. Field research was conducted in 2022–2023 in the Berezanskoe Experimental seed farm in the Korenovsk district of the Krasnodar Territory. Geographical location of the research: Krasnodar – 45°04' north, 38°98' east, altitude above sea level – 29 m. Sunflower was cultivated according to the classical technology generally accepted for the region. The repetition in the experiment is threefold; the area of the plot is 112 m2 . Data on the variability of plant height and basket diameter of the studied hybrids and their productivity depending on the seeding rate are presented. On average, over the two years of research, the sunflower hybrids studied differed in their alignment in plant height and basket diameter. With an increase in the seeding rate from 60 to 80 thousand units/ha, the height of plants increased by 3.2–6.3 cm, and the diameter of the basket decreased by 1.4–2.1 cm, on the contrary, the seeding rate decreased from 60 to 40 thousand. pcs/ ha lowered the height of plants by 3.8–6.3 cm, while adding the diameter of the baskets by 1.5–2.8 cm. As a result of the study, it was found that in the common chernozem of the Western Ciscaucasia, under conditions of sufficient moisture supply, the highest productivity of sunflower crops is achieved at a seed sowing rate of 80 thousand units/ ha, and the most productive hybrid was Aris, which at this seeding rate formed yields and oil harvest at the levels of 4.03 and 1.68 t/ha.