Harmfulness of weeds in spring barley crops

In multifactor field experiments a close correlation is found between yield losses of two barley varieties (two-row Acha and six-row Sobolek) and air-dry biomass of weeds per unit area and proportion of their participation in total phytomass of the plant community in the crop tillering stage. The economic threshold of harmfulness 5% of the weed assemblage is calculated for both varieties. The possibility of weed control at a safe level by sowing the crop early is shown.