Chemical composition and herbicidal effects of essential oils of Cymbopogon citratus (DC) stapf, Eucalyptus cladocalyx, Origanum vulgare L and Artemisia absinthium L. cultivated in Morocco

This study is designed to examine the chemical composition of the hydrodistillated essential oils obtained from Cymbopogon citratus (DC) Stapf, Eucalyptus cladocalyx, Origanum vulgare L, and Artemisia absinthium L. GC and GC-MS analysis of the four oils has shown a determination of 18 different components representing 89.3 % of the total oil for Cymbopogon citratus (DC) Stapf that are neral (29.2 %) and geranial (18.2 %), followed by α-pinene (4.8 %) and myrcene (3.9 %) which are determined as the major compounds of the oil; for Eucalyptus cladocalyx oil there are 29 different components representing 79.0 % of the total oil, the major components are spathulenol (21.6 %) and 1,8-cineole (20.5 %), followed by p-cymene (15.1 %); for Origanum vulgare L. oil there are 25 different components representing 87.6 % of the total oil, the major components are carvacrol (34.0 %) and γ-terpinene (21.6 %), followed by p-cymene (9.4 %) and for Artemisia absinthium L. oil there are 26 different components representing 72.3 % of the total oil, which are determined as the major compounds of the oil. On the other hand, the four oils were experimented for their herbicidal activity against Sinapis avensis weed at different concentration then compared with commercial herbicides (2.4 D and glyophosate). The four essential oils have presented an interesting activities, the activity of C. citratus (DC) Stapf and E. cladocalyx have been evaluated as important. In the light of these findings, we suggested that the four essential oils may be considered as an interesting sources of bioherbicide components used as potent agents in weeds control.