Yarrow (Achillea millefolium L.) Growth at Different Altitudes in Central Italian Alps: Biomass Yield, Oil Content and Quality

Achillea millefolium L. (yarrow) is a perennial herb, native to Europe and Asia and growing wild at different environmental conditions (altitude, soil). Since ancient ages, yarrow leaves and flowers have been used as medicinal, in cosmetics, and food industries. Plant height, number of inflorescences, fresh biomass and essential oil content, yeld and composition of Achillea millefolium L. grown at different altitudes (from 250 m to 1,100 m) were studied. Plant height (from 54 cm to 77 cm) and essential oil conent per plant (from 0.16% to 0.22%) were not significantly affected by environment, while the number of inflorescences/plan, fresh biomass herb yield (from 5 Mt/ha to 12 Mt/ha) and essential oil yield (from 1.12 kg/ha to 2.51 kg/ha) were significantly influenced by environment. As far as the composition of essential oils is concerned, there was a remarkable change in some moterpenes and sesquiterpenes: in particular alpha and beta-thujone were not present in oils from fields at a higher altitude, suggesting that their synthesis depends on both genetic and environmental factors. The concentration of lavandulyl acetate, chamazulene, beta-caryophyllene, alpha-humulene and gamma-curcumene + germacrene D are greatly influenced by environmental growing conditions. From a qualitative point of view, essential oil from different environmental condition have different characteristics.