Agricultural research is increasingly focused on finding alternative, biological methods of pest control. It is known that many plant species have allelopathic properties and allelopathy may be one of the mechanisms of biological weed control in the future. Allelopathic substances responsible for biochemical interactions between plants are secondary metabolites of plants. Unlike many pesticides on natural bases present on the market, the number of preparations based on allelochemicals with herbicidal action is insufficient. Therefore, it is necessary to investigate the influence of allelochemicals on weed plant species. Cannabis sativa L., as a type of confirmed allelopathic properties, has a significant impact on cultivated and weed plant species. Finding allelopathic substances that would have negative effect on A. artemisiifolia L. is very important due to its invasiveness. Changes in guaiacol peroxidase activity are one of the indicators of oxidative stress in plants produced by allelochemicals
