EN
In laboratory tests, the influence of allelopathic substances present in the soil under Lolium perenne on seed germination and its initial growth and development as well as that of Phleum pratense and Poa pratensis, was evaluated. Results of bioassays point that water extracts from the soil under Lolium perenne sward inhibited the germination of seeds of tested grass species as well as clearly modified their initial growth and development. Negative influence of water extracts from under Lolium perenne sward can be the proof of allelopathic properties of this species.