The influence of plant growth stimulants on the formation of soybean productivity elements in the conditions of the Western Forest-Steppe

Abstract

Goal. To determine the influence of growth stimulants in foliar feeding on the formation of elements of productivity of soybean plants in the conditions of the Western Forest-Steppe of Ukraine. Methods. Field — to study the influence of the studied factors on the formation of elements of crop productivity; laboratory — to determine the qualitative indicators of yield; quantitative — to determine the parameters of the crop structure; comparative calculation, mathematical statistical — to justify the reliability of the results obtained. Results. Field studies were conducted at the Khmelnytskyi State Agricultural Experimental Station (vil. Samchyky, Khmelnitskyi oblast) of the Institute of Feed and Agriculture of the NAAS during 2021–2025 on the podzolized middle carbonaceous chornozems. During this period, the air temperature in terms of “average daily air temperature” exceeded the average long-term values. In some months, a deficit of precipitation was observed, in others, an excessive amount with an uneven distribution over the decades, which significantly influenced the growth and development of soybean plants, and the formation of productivity elements of the studied varieties. The influence of plant growth stimulants on these indicators varied over the years of research. Average for 2021–2025, 2-time treatment of crops with plant growth stimulants in the growth phases of VVSN13 and VVSN61 provided an increase in the number of productive beans per 1 soybean plant of varieties: Siverka by 1.8–3.0 pcs. (10.2–16.9%), Samorodok by 1.2–2.4 pcs. (5.7–11.4%) compared to controls. Seed productivity of 1 soybean plant in the Siverka variety increased by 3.8–5.6 pcs. (9.8–14.5%), in the Samorodok variety — by 2.9–5.3 pcs. (6,9–12,7%). The mass of seeds from 1 plant of the Siverka variety increased by 0.5–1.1 g (7.7–16.9%), the mass of seeds from 1 plant of the Samorodok variety — by 0.3–0.9 g (4.2–12.5%). Conclusions. The use of plant growth stimulants in the foliar feeding of soybeans in the growth phases of VVSN13 and VVSN61 had a positive effect on the formation of the main structural indicators — the number of beans per 1 plant, the number of seeds, and the mass of seeds of 1 plant. Among the studied options, the most effective for foliar feeding was the use of a plant growth stimulator Khimik Gumin-18.