Phytotoxic Effects of Three Origanum Species Extracts and Essential Oil on Seed Germinations and Seedling Growths of Four Weed Species

The use of chemical pesticides to protect agricultural products is a global concern because their adverse effects on the environment and public health. To avoid dangers synthetic herbicides, research has turned natural alternatives. This study was conducted evaluate allelopathic effect essential oil (EO) extracted from Origanum syriacum, onites, majorana. In addition, composition elucidated by gas chromatography mass spectrometry (GC–MS) analysis. A total 11 different components O.syriacum were identified, main carvacrol (88.49), p-Cymene (5.71), ?-Terpinene (1.63), ?-Caryoplhyllene (1.48), Terpinen-4-ol (0.65), respectively. For O. 10 compounds (58.65), Thymol (30.97), Linalool (4.17), (1.94), (0.98), Finally, for majorana, 14 (40.57), ?-Terpineol (29.28), (9.02), (5.80), methyl ether (3.46). majorana species with -Terpineol -Terpinene (5.80) as parent compound Oxygenated monoterpenes highest in all species’ EO content. EOs plant extracts tested at 5, 10, 20 L/Petri concentrations against seed germination seedling growth four weed (Thlaspi arvense, Amaranthus retroflexus, Rumex cripus, Lactuca serriola). set µL/Petri dishes germination. greenhouse experiment, final concentration solutions µL directly sprayed surface weeds, mortality rates noted after 24 48 h application. It observed that increasing application decreased phytotoxic observed, resulting 48.76–94% rates. Consequently, could be considered an alternative bio-herbicide weeds.