RÉSUMÉ
The chemical composition of essential oils isolated from the leaves of Juniperus oxycedrus by hydrodistillation was analyzed by GC-MS. 42 compounds, representing 96.73% of total oil, were identified. J. oxycedrus oil was found to be rich in α-pinene (39.63%), manoyl oxide (12.34) and z-caryophyllene (4.1%) and characterized by relatively high amounts of monoterpenes hydrocarbons and sesquiterpenes. Results of the antifungal testing by in vitro contact assay showed that the oil significantly inhibit the growth of nine plant pathogenic fungi.
RÉSUMÉ
Currently, the use of synthetic chemicals to control weeds raises several concerns related to environment and human health. An alternative is to use natural products that possess good efficacy and are environmentally friendly. Among those, essential oils have been extensively tested to assess their herbicidal properties as valuable natural resource. The essential oils whose phytotoxic activities have been demonstrated, as well as the importance of the synergistic effects among their components are the main focus of this review. Essential oils are volatile mixtures of hydrocarbons with a diversity of functional groups (ketones, ether, ester, alcohol, phenol, aldehyde …) and their herbicidal activity has been linked to the presence of monoterpenes and sesquiterpenes. However, in some cases, these chemicals can work synergistically, improving their effectiveness. Among the plant families with promising essential oils used as herbicide, Lamiaceae, Myrtaceae, Asteraceae and Anacardiaceae are the most cited. Individual compounds present in these mixtures with high activity include α-pinene, limonene, 1,8-cineole, carvacrol, camphor and thymol. Finally, although from an economical point of view synthetic chemicals are still more frequently used as herbicide than essential oils, these natural products have the potential to provide efficient and safer herbicide for humans and the environment.