title: Volatilization of the pesticides chlorpyrifos and fenpropimorph from a potato crop.
abstract: Volatilization of pesticides from crops in the field can be an important emission pathway. In a field experiment with characterization of meteorological conditions, the pesticides chlorpyrifos and fenpropimorph were sprayed onto a potato crop, after which concentrations in the air and on/in the plants were measured. Rates of volatilization were estimated with the aerodynamic profile (ADP), energy balance (EB), relaxed eddy accumulation (REA), and plume dispersion (PD) methods. The volatilization rates obtained with the ADP and EB methods were similar, while some rates obtained with the REA and PD methods in the initial period were lower. Cumulative volatilization of chlorpyrifos during daylight hours (ADP and EB methods) was estimated to be about 65% of the dosage. By far the majority of this volatilization occurred in the first few days. Competing processes at the plant surface had a considerable effect on the dissipation of fenpropimorph, so cumulative volatilization during daylight hours was estimated to be only 7% of the dosage. Plant surface residues were higher than would correspond with the volatilization rate, indicating that penetration into the leaves had occurred.
authors.affiliation: Alterra, Wageningen University and Research Centre, Post Office Box 47, 6700 AA Wageningen, The Netherlands. Minze.Leistra@wur.nl
authors.forename: Minze
authors.initials: M
authors.lastname: Leistra
authors.forename: Johan H
authors.initials: JH
authors.lastname: Smelt
authors.forename: J Hilbrand
authors.initials: JH
authors.lastname: Weststrate
authors.forename: Frederik
authors.initials: F
authors.lastname: van den Berg
authors.forename: René
authors.initials: R
authors.lastname: Aalderink
mesh_terms: D000383:Agriculture; D000393:Air Pollutants / Q000032:analysis / Q000737:chemistry*; D004390:Chlorpyrifos / Q000032:analysis / Q000737:chemistry*; D004784:Environmental Monitoring; D009025:Morpholines / Q000032:analysis / Q000737:chemistry*; D010575:Pesticides / Q000032:analysis / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry; D011198:Solanum tuberosum / Q000737:chemistry*; D013472:Sunlight; D013997:Time Factors; D014835:Volatilization
chemical_list: D000393:Air Pollutants; D009025:Morpholines; D010575:Pesticides; C050435:fenpropimorph; D004390:Chlorpyrifos