Regulators of polyamine biosynthesis, such as 1,3-propylene diamine and γ-aminobutyric acid, are involved in reducing stress in plants. Triazine herbicide application on spring barley plants under conditions of pot experiment reduced grain yield by 1.8 %. After application of mixtures with regulators of polyamine biosynthesis a decline of grain yield was obtained (statistically not significant, by 7-15 %), when compared to variant with only herbicide applied. Triazine herbicide and mixtures with regulators of polyamine biosynthesis reduced one thousand grain weight, slightly increased the number of grains in a spike. Therefore, it would be more efficient to use the regulators of polyamine synthesis independently, not together with the herbicide before tillering.