Pesticide persistence on foliage

Abstract

Background: Foliage residue decline data are used to re ne the risk assessment for herbivorous birds and mammals foraging in elds treated with plant protection products. For evaluation, current EFSA guidance has a clear focus on single-rst order (SFO) kinetic models. However, other kinetic models are well established in other areas of environmental risk evaluations (eg, soil residue assessment), and easyto-use calculation tools have become available now. We provide case studies with 6 fungicides how such evaluations can be conducted with two of these tools (KinGUII and TREC) that have been developed by Bayer. Results: SFO kinetics provided the best ts only for 13 of 36 residue decline studies conducted in a standardized design under eld conditions. Biphasic models (double rst order in parallel, hockey stick) were often superior and sometimes more conservative for risk assessment. The additional effort is manageable when using software such as KinGUII and TREC, and appears justi ed by the more reliable outcome of the evaluations. Conclusions: Further research would be useful to better assess the extent to which non-SFO better ts foliage residue decline, but our study suggests that it may be a signi cant proportion. Therefore we encourage the use of biphasic models in the regulatory risk assessment for herbivorous birds and mammals, in the ongoing revision of the European Food Safety Authority (EFSA) guidance document from 2009.

Short communication. Toxicity of emamectin benzoate to adults of Nesidiocoris tenuis Reuter, Macrolophus pygmaeus (Rambur) (Heteroptera, Miridae) and Diglyphus isaea Walker (Hymenoptera, Eulophidae) on tomato plants. Semi-field studies

“…These products have been developed for the control of Lepidoptera pests on a variety of vegetable crops worldwide (Liguori et al, 2008), with a particular eff icacy against T. absoluta. The compound is not systemic, but it exhibits good translaminar activity (Willis and Mc Dowell, 1989). Its main physiological mode of action is to stimulate the release of the γ-aminobutyric acid (GABA) neurotransmitter, thus causing a continuous flow of chloride ions into the muscle cells resulting in a suppression of contraction and paralysis (Ishaaya et al, 2002).…”

RESIDUAL EFFECTS OF PESTICIDES IN PEACH ORCHARDS ON THE MAIZE WEEVIL Sitophilus zeamais (COLEOPTERA: CURCULIONIDAE)

“…temperature and rainfall are important climatic factors that should be considered, since as Wills and mcDowell (1987), they have a direct effect on the degradation of the molecular structures of pesticides.…”

Development of a Data Set of Pesticide Dissipation Rates in/on Various Plant Matrices for the Pesticide Properties Database (PPDB)

“…For example, Willis and McDowell [24] created a data set of dissipation rates for 79 different pesticide substances on plant leaves in 1987, Katagi [25] reported data for 65 pesticides on a variety of matrices in 2004 and, Fantke and Juraske [15] collated a much larger data set of 346 pesticides, again on a range of plant matrices using 811 published studies in 2013. All of these data sets, particularly the latter one, have been hugely valuable to the risk assessment community but the value of these data, and indeed other risk assessment data, is timelimited.…”