title: Residues and half-life times of pyrethrins on peaches after field treatments.
abstract: The behavior of pyrethrins and piperonyl butoxide (PB) on peaches has been studied after field treatment. Three experiments were carried out at 1, 5, and 10x the concentration recommended by the manufacturer. In all experiments, the initial deposition was below the maximum residue level (MRL), and the half-life time calculated in the 10x experiment for total pyrethrins within 2.3 days was in agreement with the preharvest interval (PHI) recommended. In a model system, the photodegradation rates of the pyrethrins in three commercial products were compared with pyrethrum pale (PP), with and without the presence of peach waxes. The pyrethrins in formulations containing PB showed higher half-life times but were not influenced by the presence of waxes, whereas in the case of PP that does not contain any PB, photodegradation was significantly affected by the presence of waxes.
authors.affiliation: Dipartimento di Tossicologia, Università di Cagliari, via Ospedale 72, 09124 Cagliari, Italy. aangioni@unica.it
authors.forename: Alberto
authors.initials: A
authors.lastname: Angioni
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Dedola
authors.forename: Elisabeth V
authors.initials: EV
authors.lastname: Minelli
authors.forename: Andrea
authors.initials: A
authors.lastname: Barra
authors.forename: Paolo
authors.initials: P
authors.lastname: Cabras
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Caboni
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005638:Fruit / Q000737:chemistry*; D006207:Half-Life; D007306:Insecticides / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*; D010777:Photochemistry; D027861:Prunus / Q000737:chemistry*; D011722:Pyrethrins / Q000008:administration & dosage* / Q000032:analysis* / Q000737:chemistry; D013472:Sunlight
chemical_list: D007306:Insecticides; D010573:Pesticide Residues; D011722:Pyrethrins