VARIATION OF SOYBEAN AGRONOMY PHYTOMETRIC PARAMETERS DEPENDING ON THE USE OF DISINFECTANTS

One of the most important agrotechnical practices that contributes to achieving high crop yields is seed treatment, which enhances plant resistance to diseases and adverse environmental conditions. The aim of this study was to assess the impact of various seed treatments on the phytometric parameters of the soybean agroecnosis and yield under the soil and environmental conditions of the foothill zone of the Kabardino-Balkarian Republic. Field trials were conducted in 2021–2023 on leached chernozem soil. The objects of the study were regionally adapted soybean varieties of Russian selection, SK Optima and SK Viola, and the following seed treatments: Deposit, ME (1.0 l/t); Scarlet, ME (0.4 l/t); Oplot, VSC (0.6 l/t); and Sinclair, SC (0.6 l/t). The results demonstrated that seed treatments significantly increased leaf area, photosynthetic potential, and, consequently, yield. Treatment of soybean seeds with Deposit, ME resulted in the maximum leaf area for both SK Optima and SK Viola varieties, exceeding the control by 21.7% and 22.4%, respectively. A strong correlation was established between leaf area and yield, especially in the pod-filling and stem-branching phases (r > 0.96). Seed treatment increased the average three-year yield of SK Optima by 8.3–21.9% and SK Viola by 9.9–22.7%. Deposit, ME contributed to the highest additional seed yield: 0.42 t/ha for SK Optima and 0.46 t/ha for SK Viola. On average, over three years, the yield difference between the highest and lowest seed treatment variants was 0.26 t/ha (13.5%) for SK Optima and 0.26 t/ha (12.8%) for SK Viola, indicating significant potential for yield improvement through pre-sowing seed treatment.