Investigation of allelopathic role of grass plants in withering of black pine trees interplanted in garden of Science and Art Faculty of YTU

Most of the black pine (Pinus nigra) trees in garden of Science and Art Faculty were seen to be withered. Therefore, this study was carried out to search reason of the event that if there is an allelopathic role of grass species (Lolium perenne, Festuca rubra, Festuca arundinacea)interplanted in the same garden. The grass plants were grown in laboratory and the water extracts obtained from the plants. On the other hand, leachates obtained from the grasses in the garden. The extracts and leachate of the grasses were applied to black pine (Pinus nigra Arnold. subsp. pallasina (Lamb.) Holmboe) seedlings as irrigation water in laboratory conditions and their effects were determined by measuring elongations of stem and branchs of the pine seedlings weekly during 10 weeks. As a result, growths of both stem and branchs of the pine seedlings were decreased significantly by all of the grass extracts used in the study, according to ?t? test comparing with control groups. But the grass leachate did not show any significant growth inhibitory effect on the pine seedlings. Among the grass species, the highest growth inhibitory effect was seen by Lolium perenne extracts, whereas it was lower by Festuca arundinacea. Key Words: Allelopathy, Extract, Lolium perenne, Festuca rubra, Festuca arundinace, Pinus nigra.