Vetiver oil production correlates with early root growth.

To gain insight into essential oil metabolism we analyzed the oil produced in Vetiver (Vetiveria zizanioides (L.) Nash) roots during early growth. Planting of Vetiver in the Campania region of southern Italy was performed in the spring using Vetiver culms with short roots and approximately 20 cm leaves. During the first two years of growth Vetiver essential oil was hydrodistilled from root samples collected at intervals of two months starting from transplantation. The production of Vetiver oil was constant during the first six months. Over the next two months there was a twofold increase in production of essential oil, which anticipated a progressive decrease during the cold months (from January to April 2003). The analysis of the Vetiver oil showed the presence of 49 constituents, mainly the tricyclic sesquiterpenes khusimol and zizanoic acid, and the bicyclic sesquiterpenes (E)-isovalencenol, junenol, juniper camphor, nootkatone and a-vetivone. These results suggest that Vetiver essential oil production is closely related to the metabolism of plant roots, which is affected by changes in environmental temperatures.