The studies were conducted in 2021–2023 to suppress weeds, including a particularly dangerous object of internal quarantine in our country, common ragweed (Ambrosia artemisiaflia L.) in sunflower (Helianthus annuus L.) crops. In 2021–2023, the effect of Gaur, KE (240 g/l) and Gezagard, KS (500 g/l) herbicides on weed infestation of Master sunflower crops was studied in the steppe zone of the Kabardino-Balkarian Republic. The experimental design included comparison of variants with and without a herbicide background at different application rates: 1 – control (economic); 2 – control without weeds (weeds were removed manually as they appeared on crops during the sunflower growing season); 3, 4; 5 – application of different doses of herbicides to the soil. A high degree of suppression of common ragweed (85.0–90.8 %) and other species (73.0–89.6 %) was noted against the background of application of the soil herbicide Gaur, KE in doses of 0.8 and 1.0 l/ha, applied to the soil under “blind” harrowing. This protects against losses of up to 0.5–0.9 t/ha of sunflower seeds compared to the data in the farm control (1.7 t/ha). The calculations showed that against the background of changes in the weed-field cenosis, the economic efficiency of chemical weeding was revealed. In the variants with the use of herbicides, the cost of proceeds was 21,000–23,000 rubles/ha against 15,000 rubles/ha in the farm control. When using Gaur and EC at doses of 0.8 and 1.0 l/ha, the profitability level was 114 and 122 %, respectively.