Comparative assessment of the intrinsic sensitivity of crop species and wild plant species to plant protection products and their active substances and potential implications for the risk assessment: A literature review

A comprehensive critical review was undertaken aiming to compare the intrinsic sensitivity of terrestrial plant species (crop species and noncrop wild species) with published literature and unpublished proprietary data generated for the registration of plant protection products (PPPs), and a database was compiled. Data were assessed to answer the question whether crops differ from noncrop plants in their intrinsic sensitivity to PPPs. Endpoints were assessed considering further potentially relevant parameters by means of different methods, including a quotient approach, in which overall crop endpoints were divided by matching wild species endpoints. Quotients above 1 indicated that wild species were more sensitive than crops, quotients below 1 the opposite. Further methods included a multiple regression analysis and different approaches to assess the statistical power. The overall finding was that there were no consistent differences in sensitivity between wild plant species and crop species, based on ER50, ER25, and ER10 vegetative endpoints (the largest fraction of data). This was also true when censored endpoints, seedling emergence data, and other measured variables such as shoot height were included. Statistically significant differences occurred in both directions and were balanced, that is, there was no clear trend for either crops or noncrop species to be more sensitive than the other. On the basis of multivariate regression analysis, crops were found to be significantly more sensitive than wild plant species, albeit by a small margin (factor approximate to 1.4). Minimum detectable difference (MDD) analysis and multivariate regression analysis of modified datasets indicated that when using a data set of this size and heterogeneity, any dissimilarity between crop and wild species was detectable if exceeding a factor of 1.4 in either direction. For the taxonomic groups assessed here (i.e., with data), no intrinsic difference in sensitivity to PPPs between crop species and wild plant species was found. Integr Environ Assess Manag 2019;15:176-189. (c) 2018 SETAC