Antifungal and herbicidal properties of essential oils and n-hexane extracts of Achillea gypsicola Hub-Mor. and Achillea biebersteinii Afan. (Asteraceae)

The chemical composition of essential oils isolated by hydrodistillation from the aerial parts of Achillea gypsicola Hub-Mor., Achillea biebersteinii Afan. and n-hexane extracts obtained from the flowers of A. gypsicola and A. biebersteinii Afan. was analyzed by GC and GC-MS. Camphor (40.17-23.56%, respectively), 1,8-cineole (22.01-38.09%, respectively), piperitone (11.29-0.37%, respectively), borneol (9.50-5.88%, respectively) and α-terpineol (1.56-5.15%, respectively) were found to be the main constituents in A. gypsicola and A. biebersteinii essential oils. Furthermore, hexane extracts of A. gypsicola and A. biebersteinii consist of mainly camphor (37.78-27.88%, respectively), 1,8-cineole (13.43-24.78%, respectively), piperitone (15.57%-tr, respectively), n-eicosane (1.61-9.68%, respectively), n-heneicosane (2.56-9.55%, respectively), n-tricosane (3.46-10.04%, respectively), linoleic acid (6.19-3.17%, respectively) and borneol (5.66-5.58%, respectively). Although the oils and extracts were characterized relatively by high content of oxygenated monoterpenes, hexane extracts of the plant samples relatively rich in n-alkanes, fatty acids and fatty acid esters as compared with the oil. The oils and hexane extracts were also tested against 12 phytopathogenic fungi and the oils found to be more toxic as compared with hexane extracts of the plant samples. A. gypsicola oil only did not inhibit the growth of Fusarium graminearum. The extracts also strongly increased the growth of Fusarium equiseti and F. graminearum. Therefore, the antifungal activity of the oils can be attributed to their relatively high content of oxygenated monoterpenes. The results of herbicidal assays of the essential oils and hexane extracts of the plant samples against five important weeds in cultivated areas, Amaranthus retroflexus L., Chenopodium album L., Cirsium arvense L. (Scop.), Lactuca serriola L. and Rumex crispus L. showed that, in particular, the oils had inhibitory effects on the seed germination and seedling growth of A. retroflexus, C. arvense and L. serriola. The hexane extracts also showed lower herbicidal effect against the weeds in comparison to that of the oils. The findings of the present study suggest that the essential oils have a potential to be used as herbicide as well as fungicide.