Resistance of Fungi Against Fungicides


Fungicides are used to control fungi in almost all agricultural and horticultural crops. However, since 1970 it has occurred several times that fungi become resistant to some fungicides. Since the first cases of resistance, much has been done by all concerned to analyze this phenomenon and to develop measures that can prevent fungi from becoming resistant. Within the Fungicide Resistance Action Committee (FRAC), international guidelines for such measures are drawn up by representatives of agrochemical companies (see: On this site you can find the FRAC code list, information material and background information. In a number of countries, including the Netherlands, regional groups (FRAG’s: Fungicide Resistance Action Groups) have been set up to deal with fungicide resistance.



A regional fungicide resistance working group has been active in the Netherlands since 2004, dealing with all aspects of resistance of fungi to fungicides in the Netherlands. Since 2014 this working group is affiliated with the KNPV as Fungicide Resistance Working Group. To keep the link with the internationally working FRAC, the working group can also be found as FRAG-NL. The working group consists of representatives of agrochemical companies, the Board for the Authorisation of Plant Protection Products and Biocides (Ctgb), several researchers, a representative of the Netherlands Food and Consumer Product Safety Authority (NVWA) and a representative of the HAS University of Applied Science in Den Bosch. The chairman of the working group is Erno Bouma*, HAS Den Bosch and Ivonne Elberse* from the NVWA is secretary.

*) the email addresses are at the bottom



The working group has the following objectives:

  • Produce, publish and promote educational material that can assist in understanding and reducing fungicide resistance; for both consultants and end users.
  • Collect and interpret information regarding fungicide resistance and its management in order to build consensus in the Netherlands.
  • Offer a point of contact between industry (FRAC), government and independent research institutes.
  • Develop a national strategy, in cooperation with the FRAC, in case of loss of important active substances.
  • Promote practical guidelines regarding the status and management of fungicide resistance in the Netherlands; advise on topics where Research & Development is needed.


For further information, please contact the Secretary (Ivonne Elberse, ) or the Chair (Erno Bouma, ) of the KNPV Fungicide Resistance Working Group / FRAG-NL.