General SDHI Guidelines (all crops):

(Updated in December 2018, changes in bold)

Strategies for the management of SDHI fungicide resistance, in all crops, are based on the statements listed below. These statements serve as a fundamental guide for the development of local resistance management programs.  Resistance management strategies have been designed to be proactive and to prevent or delay the development of resistance to SDHI fungicides.

  • A fundamental principle that must be adhered to when applying resistance management strategies for SDHI fungicides is that:
The SDHI fungicides (benodanil, benzovindiflupyr, bixafen, boscalid, carboxin, fenfuram, fluindapyr, fluopyram, flutolanil, fluxapyroxad, furametpyr, inpyrfluxam, isofetamid, isoflucypram, isopyrazam, mepronil, oxycarboxin, penflufen, penthiopyrad, pydiflumetofen, sedaxane, thifluzamide) are in the same cross-resistance group.

  • Fungicide programs must deliver effective disease management. Apply SDHI fungicide based products at effective rates and intervals according to manufacturers’ recommendations. 
  • Effective disease management is a critical component to delay the build-up of resistant pathogen populations. 
  • The number of applications of SDHI fungicide based products within a total disease management program must be limited.
  • When mixtures are used for SDHI fungicide resistance management, applied as tank mix or as a co-formulated mixture, the mixture partner: should provide satisfactory disease control when used alone on the target disease and must have a different mode of action.
  • Mixtures of two or more SDHI fungicides can be applied to provide good biological efficacy; however, they do not provide an antiresistance strategy and must be treated as a solo SDHI for resistance management. Each application of such a mixture when used in a spray program counts as one SDHI application.
  • SDHI fungicides should be used preventively or at the early stages of disease development. 
  • Please refer to FRAC Recommendations for Mixtures - January 2010 for more information on fungicide mixtures for resistance management.
  • Species can carry different mutations which affect SDHIs. A few mutations can lead to different sensitivities depending on the chemical structure of the active ingredient.
  • As SDHIs are cross-resistant, resistance management must be the same for all SDHIs.
  • All monitoring and guideline related statements refer to the entire group of SDHIs.

Monitoring Results and Use Recommendations

At the annual meeting, the working group reviews the current year's monitoring results and decides whether they require changes be made to the next year's use recommendations.  The minutes of those meetings are below.




Kristin Klappach picture

Dr. Kristin Klappach

Agricultural Research Station Limburgerhof
D-67114 Limburgerhof,

Tel: +49 62160- 27287
Fax: +49 62160- 6627287