Herbicides for lamb's quarters control in soybean crops

The results of the study of toxicity level for the lamb's quarters (Chenopodium album L.) of well-known herbicides used in soybean crops as well as herbicides promising for soybean production in the Far East are presented. Lamb's quarters (Chenopodium album L.) is a highly noxious weed species that is widespread in the south of the region. Weediness monitoring conducted in 2006-2020 showed that this species was present in the Primorsky Territory on 63-100% of fields occupied by soybeans with an average growth density of 3-117 pcs/m2. In 2013-2020 in a series of experiments, conducted in the conditions of the vegetation house and on the experimental fields of the institute, the toxicity level for Common lamb's quarters was determined by 20 herbicides (based on 14 active substances) used in soybean crops. It was found that the control of this weed species is most effective when applying herbicides in the soil and treating plants with a height of up to 4-11 cm at the early stages of development - 1-3 pairs of leaves. Reliable suppression of lamb's quarters in experiments was provided by the soil (before sowing or before soybean seedlings) use of herbicides containing active substances metribuzin, imazetapir, trifluralin, pendimetalin and acetochlor. Among the active ingredients of the tested foliar herbicides, fomesafen, combinations of bentazone + acifluorfen and imazamox + chlorimuron-ethyl were the most toxic for lamb's quarters. It is recommended to use the following herbicidal preparations to control the spread of lamb's quarters: before sowing or sprouting of soybeans - Lazurit, Zenkor Ultra, Pivot, Proponit, Fabian; for processing vegetative plants - Flex, Galaksi Top, Concept, Classic Forte (Harmony Classic), Proponit.