Volatilization of the pesticides chlorpyrifos and fenpropimorph from a potato crop.
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.
Leistra
Minze
M
Alterra, Wageningen University and Research Centre, Post Office Box 47, 6700 AA Wageningen, The Netherlands. Minze.Leistra@wur.nl
Smelt
Johan H
JH
Weststrate
J Hilbrand
JH
van den Berg
Frederik
F
Aalderink
René
R
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
D000393:Air Pollutants; D009025:Morpholines; D010575:Pesticides; C050435:fenpropimorph; D004390:Chlorpyrifos