22nd Meeting of the Panel on Efficacy Evaluation of Herbicides
and Plant Growth Regulators

Braunschweig (DE), 2023-02-15/16



The 22nd Meeting of the Panel on Efficacy Evaluation of Herbicides and Plant Growth Regulators took place in Braunschweig (DE) on 2023-02-15/16. Special thanks are due to Mr Zwerger and his colleagues from Julius Kühn-Institute for the warm hospitability and excellent organization of this meeting. Mr Zwerger and Ms Ulber presented the research activities of Julius Kühn-Institute on weed research to the Panel members. This included a demonstration of the facilities used for resistance testing, phenotyping of weeds and for efficacy assessment of herbicides.


Panel members


The Panel discussed Standards for conducting field trials to evaluate the efficacy of herbicides and plant growth regulators.


The Panel worked on the development of two new Standards:

  • PP1 (NEW) Efficacy assessment of herbicides if longterm control of perennial weeds is claimed.
    This Standard once developed will be an addition to the specific Standards on herbicides. Its focus is on assessments carried out during the second lifecycle of the weed after application.
  • PP1 (NEW) Efficacy assessment of combinations of herbicides and mechanical control measures.
    The Standard will cover the principles of efficacy testing of integrated approaches to weed control and will apply across all crops.


This work will continue as further improvement of the drafts is needed.


The Panel discussed herbicide-specific issues in relation to principles of efficacy and crop safety extrapolations for major uses. The Panel agreed that extrapolations between major crops should be possible for the same target weed and for the same claimed dose.


The activities of the Minor Uses Coordination Facility were presented to the Panel. The Panel was also updated concerning the EPPO Resistance Database and the status of the development of an EPPO Database for extrapolation possibilities for minor uses.


The next meeting of the Panel is tentatively scheduled for February 2024 in Paris.