The effectiveness of applying herbicides incorn growing technology

Studies conducted on the chernozems of the steppe zone of Ukraine have revealed a direct relationship between thephytosanitary condition of an agricultural ecosystem and the amount of productive moisture used by corn plants from the 0 to 150 cmsoil layer during the period from sowing to harvest. In absolutely cleancrops, corn plants used soil water to the 156 mm depth, while in the plotsfrom which the weeds were not removedsoil water was used to 203 mm and on theherbicide-treated soilto 168–171 mm depth. Full or partial control of weediness of crops makes it possible to save 320–470 m3/ha moisture reserves, which is equal to the average monthly precipitation that fell during the growing season (2018–2019). Effectiveness of the tested crop chemical protection systems was to a large extend determined by the hydrothermal conditions in April - May. High air temperature, lack of agronomically useful rains and dry winds caused drying out of the upper soil layer and decreasedphytotoxicity of pre-emergence herbicides. In this case (2018), the largest percentage of the first wave weeds (89.1 %) was destroyed by a tank mixture of crop protectionagents contained in Frontier Optima (0.8 l/ha + Stellar (0.8 l/ha) + Metolat (0.8 l/ha). In favorable weather, to ensure manifestation of toxicological properties of soil herbicides (2019), the following combined technological schemes for harmful species control in the first stages of corn organogenesis had an advantage: Dual Gold (1.5 l/ha) (before sowing), Stellar (1.25 l/ha) + Metolat (1.25 l/ha) (after emergence of seedlings) and Acris(3 l/ha) (before sowing), Kelvin Plus (0.35 kg/ha) + Hasten (1 l/ha) (after emergence of seedlings). The technical efficiency of the herbicide application reached 98–100 %. In 2018, the highest yield of corn grain (7.85 t/ha) in the protected plots was obtained after application (in the phase of development of 3–5 corn leaves) of the following tank mixture: Frontier Optima (0.8 l/ha) + Stellar (0.8 l/ha) + Metolat (0.8 l/ha). This combination turned out to be the most effective in terms of cost effectiveness of grain production, providing a profitability of 213 %. In 2019, we managed to increase the yields by combining soil and crop protection herbicides. Given the cost and consumption rate of the herbicides used per 1 ha, a combination of synthetic agrochemicals Avatar (2.5 l/ha) (before sowing) + Prima (0.5 l/ha) (after emergence of seedlings) was the best in terms of the main product cost (1579 UAH/t) and profitability (134 %). Key words: weeds, herbicidal system, technical efficiency, productivity, profitability of production.