18th Meeting of the Expert Working Group on Resistance to Plant Protection Products

Athens, 2023-09-20/22



The Expert Working Group (EWG) on Resistance to Plant Protection Products met in Athens at the Institute of Mediterranean Forestry Ecosystems (ELGO-DIMITRA), on 2023-09-20/22. Special thanks are due to Anastasia Tsagkarakou for the warm hospitability and the excellent organization of this meeting.


The EWG continued discussing the EPPO Database on resistance cases. The aim of this database is to share information among the responsible authorities for registration of plant protection products across the EPPO region and between authorities and the agrochemical companies which apply for registration of their products. The database is publicly available since September 2021. All EPPO members countries are invited to appoint an official contact point and provide information about resistance cases in their respective countries to the EPPO Secretariat through this contact point. So far 22 EPPO member countries have nominated a contact point and 16 of them entered resistance cases in the database


EPPO Database on Resistance Cases 



In addition to the 557 resistance cases already validated in previous EWG meetings (and visible in the database for all users), this year the EWG considered 270 new (or updated) cases and most of them were validated. The cases validated at the meeting are now visible for all users of the database. The cases which could not be validated at the meeting will need further work or consideration by the countries that proposed them.


Expert Working Group


A regular topic on the agenda is the update from Panel members on current and new resistance cases and management strategies. Country presentations were made by France, Germany, Greece, the Netherlands and Portugal. Thomas Gitsopoulos (ELGO-DIMITRA) gave a presentation about the main cases of herbicide resistance in Greece. Prof. John Vontas (Agricultural University of Athens) presented the results of molecular diagnostics research for resistance monitoring in major agricultural pests in Greece. Anastasia Tsagkarakou (ELGO-DIMITRA) recalled the existence of the Greek database for resistance, Galanthos . Most of the cases in this database are also reported in the EPPO Resistance Database. An expert from the United Kingdom, Deborah Jarratt (CRD) presented the results of the project Development of a regulatory tool for sustainably managing PPP fungicide mixtures for resistance .


Country presentations were followed by information from the Resistance Action Committees (RACs). The industry representatives informed the Panel about the new developments and recent activities of:

  • the Fungicide RAC (FRAC)
  • the Insecticide RAC (IRAC)
  • the European and Global Herbicide RAC (EHRAC)


The EWG also discussed the progress of a new draft Standard on generating sensitivity data for PPPs resistance monitoring and the plan for an EPPO Workshop on Resistance to PPP which could be held in 2025.


The EPPO EWG on Resistance will next meet on 2024-10-01/03 in Paris. A webinar for EPPO countries about the EPPO Resistance Database is planned for 2024.