title: Persistence in and Release of 2,4-D and Azoxystrobin from Turfgrass Clippings.
abstract: Research has shown that pesticide residue in clippings from previously treated turfgrass may become bioavailable as grass decomposes, adversely affecting off-target organisms. We conducted a field study to quantify 2,4-D (2,4-dichlorophenoxyacetic acid) and azoxystrobin (methyl(E)-2-{2[6-(2-cyanophenoxy)pyrmidin-4-yloxy]phenyl}-3-methoxyacrylate) residues in turfgrass clippings collected from hybrid bermudagrass [ (L.) Pers. × Burtt-Davy], tall fescue [ (Schreb.) S.J. Darbyshire], and zoysiagrass ( Steud.). A subsequent greenhouse experiment was conducted to measure pesticide release from clippings into water. 2,4-D (1.6 kg a.i. ha) and azoxystrobin (0.6 kg a.i. ha) were applied to field plots at 32, 16, 8, 4, 2, 1, or 0 d before collection of the clippings. Clippings were collected from each experimental unit to quantify pesticide release from clippings into water. Both 2,4-D and azoxystrobin were detected when turfgrass was treated over the 32-d experimental period, suggesting that clipping management should be implemented for an extended period of time after application. Pesticide residue was detected in all water samples collected, confirming 2,4-D and azoxystrobin release from turfgrass clippings; however, pesticide release varied between compounds. Two days after clippings were incorporated in water, 39 and 10% of 2,4-D and azoxystrobin were released from clippings, respectively. Our research supports the currently recommended practice of returning clippings to the turfgrass stand when mowing because removal of 2,4-D and azoxystrobin in clippings may reduce pest control and cause adverse off-target impacts.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Jeffries
authors.forename: Fred H
authors.initials: FH
authors.lastname: Yelverton
authors.forename: Khalied A
authors.initials: KA
authors.lastname: Ahmed
authors.forename: Travis W
authors.initials: TW
authors.lastname: Gannon
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000032:analysis* / Q000737:chemistry; D031744:Cynodon; D005659:Fungicides, Industrial; D008689:Methacrylates; D010573:Pesticide Residues / Q000032:analysis* / Q000737:chemistry; D006109:Poaceae; D011743:Pyrimidines / Q000032:analysis* / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry; D000073739:Strobilurins / Q000032:analysis* / Q000737:chemistry
chemical_list: D005659:Fungicides, Industrial; D008689:Methacrylates; D010573:Pesticide Residues; D011743:Pyrimidines; D012989:Soil Pollutants; D000073739:Strobilurins; D015084:2,4-Dichlorophenoxyacetic Acid; C087670:azoxystrobin