Abstract:
Oregano (Origanum onites L.) a highly valued medicinal plant, is rich in essential oil. The objective of the experiment was to determine the relative importance of planting densities on yield components and essential oil components of O. onites under semi and rain fed conditions of South East Anatolian Turkey. Plant densities and environmental conditions affected growth components, essential oil percentage and essential oil yield variabilty. The results suggested variation among fresh and dry herb yield, dry leaf yield and essential oil composition in O. onites during two years of experimentation. Totally-twenty-six components were identified in the oregano essential oil by GC-MS. Carvacrol (39.6 - 52.2 %) dominated all components identified in the essential oils. 45 x 20 cm plant density showed economical optimum herbage and oil yield on the non-calcareous and soils of Diyarbakir in the Southeastern Anatolian Turkey.