Efficacy of Slow-Release Formulations of Metribuzin and Tribenuron Methyl Herbicides for Controlling Weeds of Various Species in Wheat and Barley Stands

The herbicidal activity of long-acting formulations of metribuzin and tribenuron methyl herbicides embedded in granules prepared from a mixture of degradable poly(3-hydroxybutyrate) and birch wood flour was studied in laboratory-grown weeds of various species and in wheat Triticum aestivum and barley Hordeum vulgare stands infested by weeds. The constructed formulations effectively suppressed all species of weeds studied. The biological effectiveness of herbicide formulations toward intact plants in wheat and barley stands infested with weeds was close to 100%, which was significantly higher than the effect of their free forms. The more effective suppression of weeds by embedded herbicides was beneficial for the growth of crops whose aboveground biomass was 8-13 to 20% greater than that of the crops in the treatments with free herbicides. Embedded metribuzin and tribenuron methyl exhibit sustained and pronounced herbicidal activity and are effective for pre-emergence soil application for crops infested with weeds of various species.