title: Fate of isoxaben in a containerized plant rhizosphere system.
abstract: Commercial production of ornamental plants is an important industry in the United States and involves a complex technology that includes the use of herbicides. Isoxaben[N-[3-(1-ethyl-1-methylpropyl)-5-isoxazolyl]-2,6-dimethoxybenzamide] is a pre-emergence herbicide used for controlling weeds in many areas including containerized ornamental plants. Degradation was studied in potting mix (80% bark, 20% sand) with three different regimes (sterile, bulk and rhizosphere). The rhizosphere regime contained Switch Grass (Panicum virgatum), and plants were allowed to grow for 14 days before adding isoxaben (10 microg/g potting mix). Isoxaben was degraded to 0.5 microg/g in 60 days giving a half-life of 7 days. Two degradation products were detected: 3-nitrophthalic acid in the rhizosphere and bulk regimes and 4-methoxyphenol in the sterile regime. Microbial population shifts were determined by fatty acid methyl ester profile analysis and were influenced by the introduction of a plant (rhizosphere regime) and by isoxaben addition.
authors.affiliation: Department of Microbiology, Clemson University, Clemson, SC 29634-0377, USA.
authors.forename: Clyatt E
authors.initials: CE
authors.lastname: Drakeford
authors.forename: N Dwight
authors.initials: ND
authors.lastname: Camper
authors.forename: Melissa B
authors.initials: MB
authors.lastname: Riley
mesh_terms: D001549:Benzamides / Q000737:chemistry*; D001673:Biodegradation, Environmental; D006207:Half-Life; D006540:Herbicides / Q000737:chemistry*; D008897:Panicum / Q000382:microbiology; D018517:Plant Roots / Q000382:microbiology; D012988:Soil Microbiology
chemical_list: D001549:Benzamides; D006540:Herbicides; C057467:isoxaben