Effects of phenological stages on herbage yield and quality/quantity of oil in garden thyme(Thymus vulgaris L.)

摘要

Garden thyme (thymus vulgaris) belongs to Lamiaceae family. Thyme is widely used in pharmacy, cosmetics and Food industries of developed countries; it is a strong disinfectant with antioxidant. In order to determine the effects of phenological stages on herbage yield and quality/quantity of oil in Garden thyme, this study was conducted in research farm of Khorasgan (Isfahan) branch of Islamic Azad University in 2009 to 2010 years using a randomized complete blocks design with three replications. Plants were harvested in five phenological stages, that is, in the vegetative stage, beginning of blooming, 50% blooming, full blooming and fruit set stages. Oils were extracted by hydrodistillation for 3 h, of the aerial parts using Clevenger-type apparatus. Thymol percentage was determined by GC/MS. Results showed the significant effects of phenological stages on essence and thymol yield and percentage. Mean comparison showed that beginning of blooming has significantly the highest essence efficiency (2.42%). According to GC/MS analysis, thymol was the main compound of essence in all-phenological stages. On the whole, it is recommended to harvest this plant in 50% blooming to gain the highest essence and thymol yield as well as fresh and dry herbage.