Effectiveness of sequential herbicide application Flex with graminicides in soybean crops. V.N. MOROKHOVETS, T.V. SHTERBOLOVA, T.V. MOROKHOVETS, S.S. VOSTRIKOVA, Z.V. BASAI, N.S. SKORIK

Abstract

Effectiveness of sequential herbicide application Flex with graminicides in soybean crops. V.N. MOROKHOVETS, T.V. SHTERBOLOVA, T.V. MOROKHOVETS, S.S. VOSTRIKOVA, Z.V. BASAI, N.S. SKORIK (Far Eastern Research Institute of Plant Protection, Primorsky Krai, Kamen-Rybolov village).

In the Far-Eastern Scientific Research Institute of Plant Protection in plot experiment studied the biological and economic efficiency of new herbicide Flex in crops of soybean varieties Asuka when the culture development phase was two trifoliate leaf. The research was carried out in 2019 using generally accepted methods on meadow-brown podzol 1.5 l/ha with surfactant Trend 90 0.2 l/ha and graminicides Fusilade Forte 1.5 l/ha and Centurion 0.3 l/ha in a mixture with Amigo Star 0.6 l/ha for a complex of annual dicotyledonous and cereal weeds during the entire growing season of soy was established. The decrease in the total biomass of weeds in these variants of the experiment was 97–99 %. High sensitivity to the Flex herbicide (weight reduction by 99–100 %) was shown by ragweed, which occupies a leading position among annual broad-leaved weeds in frequency of occurrence and density of growth in the region. The new product was also effective in suppressing marsh cress, common lambsquarter, and Asian copperleaf. The imposition of graminicides Fusilade Forte and Centurion with Amigo Star three days after treatment of soybean crops with Flex preparation contributed to the effective control of annual cereal weeds: cockspur grass, species of bristlegrass and hairy cupgrass (weight reduction by 75–100 %).

The toxic effect of the Flex preparation on dicotyledonous perennial species was mainly manifested in inhibiting the growth of aboveground plant mass, which in the experimental versions was 55–88 % lower than the control one when taken into account for the first time after treatment. By harvesting soybeans, the herbicidal effect on this group of weeds was weakened, mainly due to the mass build-up of curled dock. The high biological activity of the new herbicide and graminicides ensured the preservation of a significant part of the crop. In the experimental versions, the yield of soybean seeds increased by 0.41–0.44 t/ha compared to the control (0.87 t/ha). The economic efficiency of using the Flex herbicide with subsequent application of graminicides was 3.64–3.96 thousand rubles/ha.