J.V. López

Seasonal Variation of Essential Oil Yield and Composition of Thyme (Thymus vulgaris L.) Grown in Castilla—La Mancha (Central Spain)

Abstract Links between phenology, yield and composition of the essential oil of common thyme, Thymus vulgaris L., grown in Guadalajara (Central Spain) were determined in the different phases of the biological cycle during one year. Data showed an average yield of about 2%. The analysis of the oil components was carried out by GC-FID and GC/MS. The main oil constituents were thymol (36.3–47.5%), p-cymene (13.0–27.8%) and γ-terpinene (5.3–16.2%), which is in accord with a thymol chemotype. The highest yield of oil was obtained in the period of full flowering and the highest concentration of thymol in the period of initial flowering.

Biomass and essential oil yields of cornmint (Mentha arvensis L.) grown in the irrigation area of Río Dulce, Santiago del Estero, Argentina

The aim of this study is to determine the yield and composition of the essential oil of cornmint (Mentha arvensis L.) grown in the irrigation area of Santiago del Estero, Argentina. Field tests were carried out under irrigation conditions, harvesting when 70% flowering was reached (in the summer and at the end of the winter seasons). Essential oil yields were 2% in the first cut and 1.6% in the second cut, respectively, the major constituents of the essential oil being menthol, menthone, isomenthone and menthofuran. In both cases, a high concentration of menthol was obtained, although during the winter the content decreased, increasing the concentration of menthofuran. It is concluded that during the summer a higher yield and better quality of essential oil are produced.