Herbicidal effects of n-hexane, ethyl acetate and methanol extracts of cogon grass (Imperata cylindica l.) and their phytotoxicity on spiny amaranth (Amaranthus spinosus l.) growth

Abstract This research has the purpose of examining activities herbicidal effect n -hexane, ethyl acetate and methanol extracts cogon grass ( Imperata cylindica L.) on spiny amaranth Amaranthus spinosus The rhizomes I. cylindrica were extracted with acetate, methanol, in that order. tested A. at concentrations 5%, 10%, 15%, 20%. We applied a synthetic herbicide concentration 0.686 kg (2,4-D a.i. ha −1 ) for positive control, negative we used water without any chemicals (distilled water). affects weed leaf area, root length, shoot dry weight . application 20 percent -hexane extract was best treatment terms controlling (40.83%), but it not different from other organic solvent treatments various concentrations, contrast to aquades (0.00%) herbicides (100%). showed strongest after 28 DAA, while only minimal effect. Gas Chromatography-mass spethroscopy (GC-MS) analysis rhizome contained 3 key compounds each as under : [phthalic acid (43.30%), dibuthyl phthalate (29.75%), linoelaidic (5,93%)]; [propanetriol (31.73%), phthalic (5.69%), -hexadecanoic (5.39%)]; [acetic (52.95%), acetamide (21.86%), octaethylene glycol monododecyl (11.34%). proved promising control