Herbicidal and Fungicidal Effects of Cuminum cyminum, Mentha longifolia and Allium sativum Essential Oils on Some Weeds and Fungi

In this study, chemical compositions of essential oil extracted from Cuminum cyminum L., Mentha longifolia L. and Allium sativum L. were analysed using GC and GC-MS methods. The herbicidal effects of the essential oils on seed germination, root and shoot growth of Rumex crispus L. and Convolvulus arvensis L. were investigated. Meanwhile their effects regarding the mycelial development in Verticilium dahlia Kleb. and Fusarium oxysporum Schl. were also evaluated. Only the highest three concentrations; 10, 15, 20 mu g/cm(2) of A. sativum L. were 100% inhibited the seed germination, root and shoot growth of R. crispus L.; C. cyminum L. and M. longifolia L were affected at a rate of 100% by the four concentrations. All the three essential oils showed significant effect (100%) in the parameters examined against C. arvensis L. The essential oils obtained from C. cyminum L., M. longifolia L. and A. sativum L. were found to be 100% effective on V dahlia Kleb. mycelium growth in all concentrations examined. However, C. cyminum L. and M. longifolia L. essential oils were found to be 30.0-36.6% effective at the concentration of 5 mu g/cm(2) on mycelium development of F oxysporum Schl.; and the other 3 concentrations totally inhibited the growth of the fungi. The essential oil of A. sativum L. was the most effective; and 100% inhibition of the mycelial growth of F oxysporum was detected in all concentrations. The oils used in the study have the potential of being used as herbicides and fungicides.