Bayer AG, Crop Science Division, Monheim, Germany.
gaiac Research Institute for Ecosystem Analysis and Assessment, Aachen, Germany.
Integr Environ Assess Manag. 2020 Sep;16(5):691-705. doi: 10.1002/ieam.4263. Epub 2020 Apr 16.
During herbicide spray application, nontarget terrestrial plants (NTTPs) growing in the off-field area need to be protected from unacceptable effects of herbicide drift. The risk of such unintended effects is assessed in order to establish whether a particular use can be approved, possibly in combination with mitigation measures. In Europe, the risk of herbicide treatment to NTTPs is assessed on the basis of tier 2 studies done under controlled conditions in greenhouses. Following the concept of a tiered testing approach, higher tier field studies under more realistic conditions could be used to refine the risk assessment. No current guideline for conducting higher tier NTTP field studies is available. We developed an NTTP higher tier field study method done on an experimental plant community established by sowing of a seed mixture. The setup was optimized in 3 pilot field studies and subsequently used for a definitive study testing effects of the herbicide iofensulfuron-sodium. Results show that the method can be regarded as a suitable higher tier option for assessing effects of herbicides on NTTPs. Growth of species from the soil seed bank cannot be avoided and has to be carefully considered when evaluating results. Adaptations of the study design may be necessary when testing different herbicides. Community-level endpoints were at the same level as single-species endpoints. Results of the field study were compared to standard greenhouse study results for the same herbicide. No observed effect rates (NOERs) in the field were about a factor of 10 higher and show that the current tier 2 risk assessment for NTTPs can be regarded as protective in this case. Whether the present field study design and the assessed endpoints can be used in higher tier risk assessment of NTTPs depends on selection of the specific protection goal and requires further discussion. Integr Environ Assess Manag 2020;16:691-705. © 2020 Bayer AG. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
在喷洒除草剂时，需要保护场外生长的非靶标陆生植物（NTTP）免受除草剂飘移的不可接受影响。评估这种意外影响的风险是为了确定特定用途是否可以获得批准，可能需要结合缓解措施。在欧洲，根据在温室中进行的受控条件下的二级研究评估除草剂处理 NTTP 的风险。根据分层测试方法的概念，可以使用更现实条件下的更高层次田间研究来完善风险评估。目前没有进行更高层次 NTTP 田间研究的指南。我们开发了一种 NTTP 更高层次田间研究方法，在通过播种种子混合物建立的实验植物群落上进行。该设置在 3 项试点田间研究中进行了优化，随后用于测试除草剂碘呋磺隆钠影响的确定性研究。结果表明，该方法可被视为评估除草剂对 NTTP 影响的合适的更高层次选择。物种的生长无法避免，在评估结果时必须仔细考虑。在测试不同的除草剂时，可能需要对研究设计进行调整。群落水平的终点与单一物种的终点相同。田间研究的结果与相同除草剂的标准温室研究结果进行了比较。在田间未观察到效应率（NOER）高出约 10 倍，表明在这种情况下，目前针对 NTTP 的二级风险评估可以被认为是具有保护性的。目前的田间研究设计和评估终点是否可以用于 NTTP 的更高层次风险评估取决于特定保护目标的选择，并需要进一步讨论。《综合环境评估与管理》2020 年；16：691-705。©2020 拜耳公司。《综合环境评估与管理》由 Wiley 期刊出版公司代表环境毒理化学学会（SETAC）出版。
