THE ROLE OF PLANT GROWTH REGULATORS IN THE FORMATION OF SUNFLOWER HYBRIDS PRODUCTIVITY

Abstract

The results of the study of the influence of plant growth regulators and basic nutrients on the productivity of sunflower hybrids of different maturity groups are presented. The research was carried out on the basis of the farm of LLC "Organic-D" in the village of Sutisky, Vinnytsia region, during 2021-2022. The soils of the experimental plot are gray forest soils with medium loamy texture and slightly acidic reaction of the soil solution. The content of the main nutrients is typical for this type of soil. The research was conducted on three sunflower hybrids: early maturing –Oskil, mid-early - NK Delphi and mid-early - NK Condi by applying the plant growth regulator (PGR) DEFENDA Vertex (0.5 l/t) and mineral fertilizer at the rate of N45P45K45 d.p. m. The technology of sunflower cultivation is generally accepted for the conditions of the Right-Bank Forest-Steppe of Ukraine, except for the factors under study. We have found that the use of seed treatment with PPP DEFENDA Vertex and the application of mineral fertilizers at the rate of N45P45K45 on the crops of the studied sunflower hybrids of different maturity groups led to an improvement in the morphological structure of plants, an increase in their productivity, which ultimately led to an increase in oil yield per unit area. The maximum value of plant height, number of flowers and seeds in the basket of the studied hybrids in the variant with the combined application of mineral fertilizers at the rate of N45P45K45 with the treatment of seeds with PPP DEFENDA Vertex: Oskil - 163.3 cm, 1129 pcs. and 923 pcs, NC Delphi - 187.1 cm 1247 and 967 pcs. and NC Condi - 171.7 cm 1335 and 995 pcs. respectively. The highest level of yield, on average for two years of research, was obtained in the variant with the use of seed treatment with PPP DEFENDA Vertex and the application of mineral fertilizers at the rate of N45P45K45 in the sunflower hybrid Oskil - 2.78 t/ha, NC Delphi - 2.95 t/ha, mid-season NC Condi - 3.09 t/ha, which is 0.48-0.59 t/ha more compared to the control variant. Seed treatment with PPP DEFENDA Vertex provided an increase in yield of 0.27-0.36 /ha, compared to the control variant (without seed treatment and fertilization). Seed treatment with PGR DEFENDA Vertex contributed to the growth of oil content in the seeds of the studied hybrids and it was 46.9%, 49.7 and 54.5%, and the combination of seed treatment with PGR DEFENDA Vertex and the introduction of mineral fertilizers in pre-sowing cultivation provided the highest value of oil content - 47.8%, 50.1 and 55.7%, respectively. The acid number of oil had an ambiguous value when using the studied factors. The highest value of huskiness was obtained when using a combination of seed treatment with PGR DEFENDA Vertex with the introduction of mineral fertilizers in pre-sowing cultivation in the hybrid Oskil - 23.7%, NC Delphi - 26.3% and NC Condi - 24.9%. The combined use of seed treatment with PGR DEFENDA Vertex and mineral fertilizers at the rate of N45P45K45 showed the highest value of oil yield per unit area - 1.47 t/ha, 1.61 and 1.72 t/ha, respectively, in hybrids Oskil, NK Delphi and NK Condi.