Inhibitory Effect of Oregano and Laurel Essential Oils and Their Main Com-ponents on Seed Germination of Some Weed and Crop Species

The essential oils from oregano (Origanum syriacum L.) and laurel (Laurus nobilis L.), their main components, namely, carvacrol, 1,8-cineole α-pinene, were tested to determine inhibitory effects on the seed germinations of three different weeds [redroot amaranth (Amaranthus retroflexus wild licorice (Glycyrrhiza glabra curled dock (Rumex crispus cutleaf ground-cherry (Physalis angulata L.)] crops [(wheat (Triticum aestivum corn (Zea mays cotton (Gossypium hirsitum L.)]. Gas chromatography/mass spectroscopy (GC-MS) analysis showed that carvacrol major components oils, respectively. An in-vitro bioassay germination test oil completely inhibited at all concentrations ranging 1 5 µl/Petri dish, while significantly decreased with increasing its 1,8-cineol α-pinene 20 dish. Oregano totally ineffective (except for concentration dish cavracrol), whereas they had a strong activity against wheat seeds. On other hand, component, 1,8-cineole, less selective action crop species. It could be concluded volatile O. cavracrol, possessed effect was some crops, utilized as bioherbicide future weed management programmes.