Application of herbicides in agrocenoses of spring barley with oversowing of perennial grasses

Abstract

The North-West region of the Russian Federation is characterized by high weed infestation and large yield losses of spring barley. At the same time, the use of herbicides in agrocenoses of spring barley with perennial grasses oversowing has its own characteristics. The aim of the study was to determine the effectiveness of herbicides Agritox, VK and Bazagran, VR against weeds in the agrocenosis of spring barley and their effect on the growth of perennial grasses during current and next years. The studies were carried out at the agroecological station of the Menkovsky branch of the Agrophysical Research Institute, located in the Leningrad region, during 2012–2019. The studies have shown significant differences in the effectiveness of herbicides Agritox, VK and Bazagran, VR in relation to weed species common in agrocenoses of spring barley with oversowing of perennial grasses in the North-West of Russia. The herbicide Agritoks, VK turned out to be less effective against stickwort and common nipplewort, and Bazagran, VR — against white goosefoot, field pansy, common fumitory and hemp-nettle. Under conditions of moisture deficit and high average daily temperatures, the herbicide Agritox, VC induced a phytotoxic effect on red clover plants, which was reflected in the accumulation of the vegetative mass of perennial grasses both in the year of growth under the cover of barley and in next years as a targeted use during hay production.