Environmental Monitoring of the 1987 Apple Maggot Project

摘要

Residues of phosmet were measured on samples of apples and leaves and in soil and water collected during the 1987 apple maggot fruit fly treatment program. The samples were analyzed to examine the dissipation of phosmet over time between successive sprays. The effect of climate on the environmental fate of phosmet was studied by monitoring and comparing results from one coastal and two inland sites. Residue levels in 1987 were lower for soil and higher for fruit than those levels found in 1986. Quality control samples indicated that these differences may have been attributed to a change in the laboratory that conducted the analyses. The 10 ppm tolerance level for apple fruit was exceeded in only one sample collected the day after phosmet was applied. At both inland sites, phosmet levels on fruit samples taken the day following applications were higher with successive applications. Possibly, shorter spray intervals accounted for the trend. No phosmet or phosmetoxon was detected (detection limit 1 ppb) in any of the surface or ground water samples that were collected. Due to inadequate sampling replication, degradation patterns were not always discernible.