Position of hemp (\kur{Cannabis sativa}) in plant protection

Cannabis sativa is a useful fibre, oil and energy plant that could be replace lot of synthetic row materials, whose production pollutes the environment. The aim of this work was to summarize the information about the occurrence of pets, diseases and weeds in the hemp stand and the possibilities of protection against them, together with information about the competitive and allelopathic characteristics of hemp and possibilities of hemp utilization in the plant protection. Though the spectrum of disease and pests is wide, until now the economics losses caused by harmful organisms are very low. Mycocentrospora cantuariensis is a potentially dangerous disease, until now this species was obserwedy on hop. Phytophtora cactorum and Septoria neocanabina belong to the new occured species. From the pests fleahopper (Psylliodes attenuata), cannabis louse (Phorodon cannabis) and european corn borer (Ostrinia nubilalis) could be the cause of the important yield losses. The hemp stand is able to suppress the weed growth due to quick development. The self-protection of hemp consists the secretion of canabinoids and volatile terpenoids, that protect not only the hemp plants but partially also neighbouring plants. These compounds and also mixed cultivation of hemp with other plants could be a new advanced tool in the plant protection