The aim of this study was to evaluate the influences of the different harvest stages
on the value and components of the essential oil (EO) of wild oregano (Origanum vulgare L.)
and European marjoram (Origanum majorana L.). Two species were collected during five stages
of vegetative and reproductive growth period with four replications. The content of EO in the
dried aerial parts was determined by hydro-distillation of herbs, and its constituents determined
by gas chromatography (GC) and gas chromatography mass spectrometry (GC/MS). The analysis
showed that the amount of EO in O. majorana was more than O. vulgare. The highest EO content
for both species were obtained in the full flowering stage. 78 and 39 components were
identified in the EO of O. vulgare and O. majorana, respectively. The main components were
germacrene D, (trans)caryophyllene, terpinene-4-ol, and a-terpinene in the EO of O. vulgare,
and terpinene-4-ol, y-terpinene, a-terpinene, and a-terpineol in the EO of O. majorana. In general,
sesquiterpene compounds had maximum amounts in the EO of O. vulgare in five stages of
growth, especially in the beginning of flowering stage. In contrast, monoterpene compounds
had maximum value in the EO of O. majorana in the full flowering stage