Allelopathic effects of some ornamental plants gowth of pine seeglings

This study was carried out to determine allelopathic effects of ornamental plants (Pelargonium zonale, Begonia toran, Vinca rosea, Impatiens walleriana ve Petunia hybrida)on growth of black pine (Pinus nigra Arnold. subsp. pallasina (Lamb.) Holmboe).The water extracts obtained from the ornamental plants were applied to the pine 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 ornamental plant extracts used in the study according to ?t? test comparing with control groups. In respect to relative growth, the highest growth inhibitory effect was seen by Pelargonium zonale extracts, whereas it was lower by Petunia hybrida.