ABSTRACT
The essential oil (EO) of Geranium macrorrhizum is produced solely in Bulgaria and the industry dates back to the end of the nineteenth century (Guenther, 1950; Gildemeister and Hoffman, 1959; Irinchev, 1956). The above-ground herbage is harvested in the autumn (September-October). In post-flowering plants, the EO content was found to be higher (0.083-0.13 per cent) than during flowering (0.05 per cent). Herbage consists of 43-49 per cent leaf blades, 39-43 per cent leafstalks, 4-8 per cent yellowing or withered leaves and flowers and 5-10 per cent rhizomes (Irinchev, 1956; Georgiev, 1995). In recent years, the availability of the wild source of G. macrorrhizum became scarce and is unavailable for industrial usage due to the new biodiversity protection laws and conservation strategies. The only way to solve the lack of resource was to amend the cultivation and increase plant productivity.
