title: Pyraclostrobin wash-off from sugarcane leaves and aerobic dissipation in agricultural soil.
abstract: To mitigate damage from the fungal sugarcane pathogen brown rust (Puccinia melanocephala), a Section 18 Emergency Use Label was put in place by the United States Environmental Protection Agency (U.S. EPA) for the application of pyraclostrobin (trade name Headline SC, produced by BASF, Research Triangle Park, NC) on sugarcane in 2008. To assess the dynamics of this fungicide in Louisiana soil, samples (n = 24) from a non-treated field were spiked with pyraclostrobin (3.1 μg g(-1)) and analyzed in laboratory conditions over the course of 63 days using quick, easy, cheap, effective, rugged, and safe (QuEChERS) dispersive solid-phase extraction/high-performance liquid chromatography with ultraviolet-visible detection (dSPE/HPLC-UV). Modeling was performed using Microsoft Excel to predict DTx values. Pyraclostrobin was found to follow biphasic kinetics with DT50 and DT90 values of 60 and 282 days, suggesting that it is moderately persistent to persistent in soils. Wash-off studies on sugarcane indicate that very little fungicide is in the wash-off after 48 h. If applied to sugarcane according to label recommendations, the fungicide should have minimal dissipation from rainfall events.
authors.affiliation: Department of Physical Sciences, Nicholls State University , Post Office Box 2022, Thibodaux, Louisiana 70310, United States.
authors.forename: James M
authors.initials: JM
authors.lastname: Fulcher
authors.forename: Darcey G
authors.initials: DG
authors.lastname: Wayment
authors.forename: Paul M
authors.initials: PM
authors.lastname: White
authors.forename: Charles L
authors.initials: CL
authors.lastname: Webber
mesh_terms: D000383:Agriculture; D001673:Biodegradation, Environmental; D002219:Carbamates / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005659:Fungicides, Industrial / Q000032:analysis*; D007700:Kinetics; D008962:Models, Theoretical; D018515:Plant Leaves; D011720:Pyrazoles / Q000032:analysis*; D031786:Saccharum; D012989:Soil Pollutants / Q000032:analysis*; D052616:Solid Phase Extraction; D000073739:Strobilurins
chemical_list: D002219:Carbamates; D005659:Fungicides, Industrial; D011720:Pyrazoles; D012989:Soil Pollutants; D000073739:Strobilurins; C513428:pyrachlostrobin