Content and Composition of M. officinalis Oil in Relation to Leaf Position and Harvest Time1.

The content and composition of the essential oil in the leaves of M. OFFICINALIS L. (Lamiaceae) cultivated under Mediterranean climatic conditions were investigated. Different leaf positions and different times of harvest during the year and during the day were considered. It was shown that in the terminal leaves, the content of essential oil was more than 0.1% higher than in the others. The results obtained also indicated a variation of the oil composition. The favourable climatic and environmental conditions of the Ebro-Delta in Spain permitted four harvests per year with a maximum of 0.4% essential oil in September. To reduce losses of volatile terpenoids, a harvest in the morning during summertime is recommended.