RESUMO
BACKGROUND: Wash-off of plant protection products from crops is represented in current European Union (EU) surface water models and future EU soil models by a coefficient that estimates its contribution to soil loadings following rainfall. Replacing the default coefficient with experimental data requires a harmonized protocol and this research forms part of the development of such a protocol. Following a successful test of the proposed protocol on a single crop across eight laboratories, a range of crops were tested in a single laboratory to assess the impact of crop type on the results. RESULTS: Six crops (wheat, rice, oil seed rape, cabbage, potato and French bean) were chosen, encompassing both hydrophobic and hydrophilic leaf surfaces. Tebuconazole (Folicur EW 250) was sprayed onto plants at a rate equivalent to 100 g ai ha-1 and subjected to a 1-h simulated rainfall event at an intensity of 20 mm h-1. Measured residues before and after rainfall were compared to calculate the percentage wash-off. The extent of wash-off was 66.4% with a 95% confidence interval of ±18.5% and the results were clustered according to leaf wettability, with lower wash-off in hydrophobic crops than in hydrophilic crops. CONCLUSION: Wash-off of this unoptimized formulation was similar across the crops, despite the use of crops with both hydrophobic and hydrophilic leaf surfaces. There is potential, therefore, to rationalize the number of crops used in future studies by selecting a small number of hydrophilic and/or hydrophobic crops to obtain a robust estimation of the extent of wash-off for use in environmental fate models. © 2024 Society of Chemical Industry.
RESUMO
There is a regulatory need for crop development dates to assess current default values used within chemical exposure assessments as well as to justify refinements within risk assessments. However, a readily available pan-European crop phenology database covering key FOrum for the Co-ordination of pesticide fate models and their USe (FOCUS) crops and scenarios to meet this need is not currently available. Therefore, we describe the development of a harmonized, pan-European, CropLife Europe Crop Development Database (C2D2), that is fully aligned with this regulatory requirement utilizing efficacy trials data generated for regulatory submissions when registering plant protection products under Regulation (EU)1107/2009. Evaluation of C2D2 against an independent data set showed good agreement for equivalent time periods, crop growth stages, and geographical regions. We illustrate how this database can be used to evaluate existing default crop development dates mandated by regulatory agencies for use within exposure assessments. Despite the large data set compiled and the geographical coverage of C2D2, not all FOCUSsw/gw scenarios have sufficient data to facilitate comparison, with less significant scenarios, like FOCUSgw Porto, being underrepresented. For those scenarios with sufficient data, clear differences between C2D2 and crop development dates assumed in the FOCUS modeling framework (using the AppDate tool) are often indicated over many growth stages, suggesting that amendment of the existing representation of crop development within the risk assessment process may be required. C2D2 is freely available under a Creative Commons license to facilitate innovation in exposure science to allow for more accurate and realistic risk assessment leading to enhanced crop and environmental protection. Integr Environ Assess Manag 2023;00:1-15. © 2023 CropLife Europe (Corteva Agriscience) and The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
