Agronomic-productive characteristics, yield and essential oil composition of a chemotype of Thymus vulgaris harvested in various phases of its biological cycle

In this paper the results of a study conducted on an ecotype of Thymus vulgaris cultivated along the coastal region of Tuscany are reported. The plants, were transplanted in open fields in the spring of 1996. During the two-year period 2000-01, surveys were performed to determine the quantity of dry matter and the composition of the essential oil produced in various phases of the biological cycle. The Thymus vulgaris plants examined showed a high production potential (6 t ha - 1 ). The oil yield from the first two cuttings was rather high, while the last cutting, carried out in January, produced a very low yield (equal to 0.14%). Based on the acidic composition of the oil extracted, the field of thyme in this study can be defined as a "thymol" chemotype. The results obtained demonstrated that the harvest period can have an effect on the qualitative characteristics of the harvested plants whose use varies according to the actual chemical composition of the oil.