Ефективність післясходових гербіцидів залежно від строків застосування в посівах сої в Східному Лісостепу України

Abstract

Goal. To determine the influence of the timing of application of multi-component postemergence herbicides on crop weediness, yield, and quality of soybean seeds in the conditions of the Eastern Forest Steppe of Ukraine. Methods. Field, weighing, statistical, analytical. Results. According to the results of research in 2017–2019, 15 types of weeds, represented by 4 agrobiological groups — early spring weeds, late spring weeds, biennials, and rhizomes — were found in soybean crops in the conditions of the Eastern Forest Steppe of Ukraine. Cereal annual weeds were dominated by number, and dicotyledonous annual weeds by raw mass. It was established that against the background of the use of anti-dicotyledons drug with the active substance bentazon + acifluorfen (in the phases of primordial leaves, 2 and 4 ternate leaves of soybeans) with a graminicide based on hyzalofop-P-ethyl (in the phase of 5 ternate leaves of soybeans), the technical efficiency of these combinations concerning the total weediness of soybean crops was, respectively: in terms of quantity at the beginning of the growing season — 65.7; 65.0 and 48.8%; by the amount at the end of vegetation — 88.6; 88.0 and 67.5%; by raw mass at the end of the growing season — 86.3; 83.9 and 62.4%. When applying the herbicide with the active substance imazetapir + propakhizafop in the phase of primordial leaves and 2-3 ternate leaves of soybean, the technical effectiveness of the effect on the total weediness of the crops was 81.7 and 58.9%, respectively, at the beginning of the growing season, and 82, 1 and 58.8% — at the end, by raw mass at the end of the growing season — 68.3 and 55.2%. The greatest increase in the yield of soybean seeds was provided by the combination of the herbicide with the active substance bentazon + acifluorfen (primordial soybean leaves) with the drug based on hyzalofop-P-ethyl (5 ternate soybean leaves) — 0.29 t/ha, or 33%, the smallest was provided by the application of the drug with the active substance imazetapir + propakhizafop in the phase of 2–3 ternate soybean leaves (0.12 t/ha, or 13%). In almost all options, with the application of herbicides, the increased collection of protein (by 0.06–0.08 t/ha) and oil (by 0.03–0.04 t/ha) was fixed. Conclusions. The use of anti-dicotyledons herbicide with the active ingredient bentazon + acifluorfen (in the phase of primordial soybean leaves) with a graminicide based on hyzalofop-P-ethyl (in the phase of 5 ternate soybean leaves) is promising for effective control of weeds in crops and ensuring an increase in the yield of soybean seeds in the conditions of the Eastern Forest Steppe of Ukraine.