Fungicide Resistance Action Committee
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In case you are interested in background information for CAA fungicides, please follow this link: Information on CAA fungicides


FRAC Recommendations for CAA fungicides

(Reviewed January 2024)  

  
General Use Recommendations (all Crops)

  • Apply CAA fungicides preferably in a preventive manner
  • Alternation with fungicides having other modes of action is recommended in spray programs
  • For more detailed product recommendations refer to the use guidelines published by the respective CAA manufacturers.

  
Specific Recommendations by Pathogens

  

Grape downy mildew/Plasmopara viticola

(Reviewed January 2024)

Plasmopara viticola
 is classified by FRAC as a high risk pathogen. Long-term experience with CAA fungicides demonstrates that the resistance risk of Plasmopara viticola to this fungicide group is moderate and can be managed through appropriate use strategies.

  • Apply CAA fungicides preferably in a preventive manner
  • Apply a maximum of 50% of the total number of intended applications for disease control not exceeding a total of 4 CAA fungicide sprays during one crop cycle. In areas of high resistance, the total number should not exceed a maximum of 3 applications during one crop cycle
  • Always apply CAA fungicides in mixture with effective partners such as multi-site or other non-cross resistant fungicides
  • An effective partner for a CAA fungicide is one that provides satisfactory disease control when used alone at the mixture rate
  • Alternation with fungicides having other modes of action is recommended in spray programs

For more detailed product recommendations refer to the use guidelines published by the respective CAA manufacturers.

Late blight of potato and tomato/Phytophthora infestans

(Reviewed January 2024)

Phytophthora infestans is classified by FRAC as a medium risk pathogen. Long-term experience with CAA fungicides demonstrates that the resistance risk of Phytophthora infestans to this fungicide group is low to moderate. For effective resistance management a precautionary strategy has to be implemented.

  • Apply CAA fungicides preferably in a preventive manner.
  • Apply a maximum of 50% of the total number of intended applications for late blight control. 
  • Apply CAA fungicides always at recommended dose rates.
  • Apply CAA fungicides using not more than 2 consecutive applications.
  • Apply CAA fungicides preferably in mixtures with effective partners belonging to different modes of action.
  • Alternation with fungicides having other modes of action is recommended in spray programs.
  • Good agricultural practices must be considered to reduce source of inoculum, disease pressure and resistance risk, e.g. consider to plant resistant varieties and refer to disease prediction models.

In regions with reported cases of resistance:

  • CAA fungicides must be used in mixtures, with not more than 2 consecutive applications.
  • In case mixtures cannot be applied for regulatory reasons, apply CAA fungicide in strict alternation.

For more detailed product recommendations refer to the use guidelines published by the respective CAA manufacturers.

Downy mildew of cucurbits/Pseudoperonospora cubensis

(Reviewed January 2024)

Pseudoperonospora cubensis is classified by FRAC as a high risk pathogen.

  • Apply CAA fungicides preferably in a preventive manner
  • Apply a maximum of 50% of the total number of intended applications for disease control not exceeding a total of 4 CAA fungicide sprays during one crop cycle. In areas of high resistance, the total number should not exceed a maximum of 3 applications during one crop cycle 
  • Always apply CAA fungicides in mixture with effective partners such as multi-site or other non-cross resistant fungicides 
  • An effective partner for a CAA fungicide is one that provides satisfactory disease control when used alone at the mixture rate
  • Alternation with fungicides having other modes of action is recommended in spray programs

For product recommendations refer to the use guidelines published by the respective CAA manufacturers.

Other Oomycete pathogens

(Reviewed January 2024)

Some of the downy mildew pathogens are classified by FRAC as moderate risk pathogens (e.g. Bremia lactucae). In spite of the use of CAA fungicides for more than 20 years against a range of such Oomycete pathogens, no reports on the occurrence of less sensitive field populations are available.

For effective resistance management, a precautionary strategy has to be implemented. 

  • Apply CAA fungicides preferably in a preventive manner 
  • Apply a maximum of 50% of the total number of intended applications for disease control 
  • Alternation with fungicides having other modes of action is recommended in spray programs 

For more detailed product recommendations refer to the use guidelines published by the respective CAA manufacturers. 

 

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.

Contact

Dr. Gerd Stammler
Chair

BASF SE
APR/FM - LI470,
67117 Limburgerhof
Germany

Tel. +49 621 60-27299
FAX: +49 621 60-27176
gerd.stammler@basf.com