Submitted to: Pan-Pacific Conference on Pesticide Science
Publication Type: Abstract Only
Publication Acceptance Date: June 1, 2003
Publication Date: June 1, 2003
Citation: KOSKINEN, W.C., CARRIZOSA, M.J., BRESNAHAN, G.A., RICE, P.J. 2003. INTERACTIONS OF ISOXAFLUTOLE AND A DIKETONITRILE DEGRADATE WITH SOILS, CLAYS, AND ORGANOCLAYS. Pan-Pacific Conference on Pesticide Science. Abstract p. 83. Technical Abstract: Isoxaflutole, a newer herbicide for weed control in corn, is rapidly transformed to a diketonitrile degradate (DKN), which is also herbicidally active. Sorption of isoxaflutole and DKN in freshly treated and aged soils, and on clays and organoclays, was characterized. Characterization of isoxaflutole sorption was difficult because of its rapid transformation. Isoxaflutole and DKN were more readily sorbed to soils with greater organic matter and clay contents and lower pH levels. Isoxaflutole sorption did not change during a 12-wk incubation, regardless of soil pH. DKN exhibited similar sorption during aging in the soils with pH > 7.0, however sorption occurred increased with time in pH 5.7 soil. No measurable DKN sorption was observed on smectites, however sorption occurred on organoclays, with more sorption on high charge quaternary alkylammonium organoclays as compared to low charge organoclays. Lack of desorption was due to DKN anion forming a chelate complex with cations.