Abstract:
The purpose of the article was to determine how foliar treatments of plants with environmentally friendly combined-action substances affect the yield of new sunflower hybrids under non-irrigated conditions of the Ukrainian
Steppe zone. The field experiments were conducted in 2021–2022 on the experimental field of the Mykolaiv State
Agricultural Research Station of the Institute of Climate-Smart Agriculture of the National Academy of Agrarian
Sciences of Ukraine under non-irrigated conditions on southern chernozem. The humus content in the arable soil
layer was 2.90%, the depth of the humus layer was 0–30 cm, and the transitional layer was 30–60 cm. The research
was conducted by establishing a three-factor field experiment, where factor A was sunflower hybrids of the Plant
Production Institute named after V.Ya. Yuriev of National Academy of Agrarian Sciences of Ukraine - Vyrii, Yarylo,
Blysk, Yaskravy and Epikur; factor B – different plant densities (30, 40 and 50 thousand/ha) and factor C – treatment
of vegetative plants in the phase of budding with substances of biological origin (Helafit Combi, Organic Balance
and Biocomplex BTU). The field experiment was located on the winter wheat forecrop. Fertilizers were applied
during the main cultivation at a dose of N30P30K30. Sowing was carried out with a row spacing of 70 cm in the last
decade of April. Yield accounting and the evaluation of the crop structure were carried out by manual threshing of
plants selected from the accounting area of the test plots and recalculation by 8% seed moisture. From the results of
observations, it was found that the foliar treatments of sunflowers with environmentally friendly combined-action
substances contributed to the prolongation of the interphase periods in the second half of the growing season of all
studied hybrids. Treatment of plants with environmentally friendly substances helped to reduce the level of damage
to all hybrids by pathogenic microflora, the highest fungicidal efficacy was observed in Helafit Combi and Organic
Balance. All hybrids formed the highest yields at a density of 40 thousand units/ha. Dense plantings up to 50 thousand units/ha were inferior in yield to the ones with a planting density of 40 thousand units/ha and were almost at the
same level as the ones with 30 thousand units/ha. Hybrids Yarylo, Epikur and Yaskravy were significantly inferior in
productivity; however, their foliar treatments also had a similar tendency to increase their productivity
