Deposition and dissipation of chlorpyrifos in surface water following vineyard applications in northern Italy

Abstract

Chlorpyrifos is an insecticide approved globally for use on a wide range of crops. Laboratory studies indicate that chlorpyrifos is toxic to fish and aquatic invertebrates, and so the adoption of practices that reduce aquatic exposure following use should be encouraged. This study assessed the exposure of surface water to the spray-drift of chlorpyrifos and the subsequent contamination of a realistic worst-case edge-of-field ditch in a vineyard in Northern Italy. Chlorpyrifos (DURSBAN 480 EC [Dow Elanco, Indianapolis, IN, USA]) was applied according to local Good Agricultural Practice (GAP) on two vineyard plots using atomizer equipment. Drift deposition and subsequent dissipation of chlorpyrifos were then monitored in an adjacent, common ditch, with an inherent buffer zone of approximately 7 m between the treated area and the ditch. The results showed that the drift loadings under the study conditions could reach predicted levels from standard spray-drift tables. However, the measured drift was highly variable due to physical factors such as the crop canopy and the distribution of vines within the rows. The amount of chlorpyrifos deposited onto the surface of the ditch water and intercepted by paper strips was approximately 2% of the applied amount after the two applications, with a maximum concentration of approximately 0.3 microg L(-1) immediately after the first application and 0.09 microg L(-1) after the second, which then dissipated from the water column within 12 to 24 h. The results showed that drift deposition spatially was variable and that chlorpyrifos residues dissipated rapidly from this surface water body. Both aspects are considered important in order to refine the aquatic risk assessment at a higher tier for both registration and management purposes.

A Bayesian approach to assessing the uncertainty in estimating bioconcentration factors in earthworms—the example of quinoxyfen

“…Following application in 2006, the mean dry‐weight soil concentration in the top 10 cm layer (less the preapplication concentration) was 28.5 µg kg −1 dw from Terrossa. It was not possible to derive a soil loading for Brognoligo because the preapplication concentration of 37.0 µg kg −1 was greater than the post‐application value of 20.9 µg kg −1 , Again there was no accumulation of quinoxyfen, as the mean soil concentrations at the end of the monitoring (autumn 2006) ranged between 9.16 and 16.0 µg kg −1 dw, in agreement with and supported by previous studies on soil accumulation and vineyard monitoring 12…”

Control Efficacy and Deposition Characteristics of an Unmanned Aerial Spray System Low-Volume Application on Corn Fall Armyworm Spodoptera frugiperda

“…The Kromekote® card arrangement affects the sampling efficiency of the droplet to some extent. Capri et al ( 2005 ) measured the off-target deposition of chlorpyrifos in two fields: one field was flat and the other field was sloped. It was indicated that the flat field deposition was higher than that of the sloped field.…”

Mitigation of agricultural nonpoint-source pesticide pollution in artificial wetland ecosystems

“…Spray drift is another way of surface water contamination (Padovani et al 2004;Vischetti et al 2007;Capri et al 2005;Ganzelmeier et al 1995). Spray drift is affected by climatic condition during the treatment, by device and by formulation used in the farm.…”