General Use Recommendations

(for 2019 no changes to previous recommendation)

Strategies for the management of QoI 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 further enhanced in order to be proactive and to prevent the occurrence of resistance to QoI fungicides developing in other areas and pathogens. Specific guidelines by crop follow the general guidelines given here.

A fundamental principle that must be adhered to when applying resistance management strategies for QoI fungicides is that:

The QoI fungicides (azoxystrobin, coumoxystrobin, dimoxystrobin, enoxastrobin, famoxadone, fenamidone, fenaminostrobin, fluoxastrobin, flufenoxystrobin, kresoxim-methyl, mandestrobin, metominostrobin, orysastrobin, pyraoxystrobin picoxystrobin, pyraclostrobin, pyrametastrobin, pyribencarb, triclopyricarb trifloxystrobin) are in the same cross-resistance group.

  • Fungicide programs must deliver effective disease management. Apply QoI 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 QoI fungicide based products within a total disease management program must be limited whether applied solo or in mixtures with other fungicides. This limitation is inclusive to all QoI fungicides. Limitation of QoI fungicides within a spray program provides time and space when the pathogen population is not influenced by QoI fungicide selection pressure.

  • A consequence of limitation of QoI fungicide based products is the need to alternate them with effective fungicides from different cross-resistance groups (refer to the specific crop recommendations).

  • QoI fungicides, containing only the solo product, should be used in single or block applications in alternation with fungicides from a different cross-resistance group. Specific recommendation on size of blocks is given for specific crops.

  • QoI fungicides, applied as tank mix or as a co-formulated mixture with an effective mixture partner, should be used in single or block applications in alternation with fungicides from a different cross-resistance group. Specific recommendations on size of blocks are given for specific crops.

  • Mixture partners for QoI fungicides should be chosen carefully to contribute to effective control of the targeted pathogen(s). The mixture partner must have a different mode of action, and in addition it may increase spectrum of activity or provide needed curative activity. Use of mixtures containing only QoI fungicides must not be considered as an anti-resistance measure.
    Where local regulations do not allow mixtures, then strict alternations with non-cross resistant fungicides (no block applications) are necessary.

  • An effective partner for a QoI fungicide is one that provides satisfactory disease control when used alone on the target disease.

  • QoI fungicides are very effective at preventing spore germination and should therefore be used at the early stages of disease development (preventive treatment).

For a printer friendly version of the General Use Recommendations see section 2.2.1 p. 13 of the "Minutes of the 2017 Meeting Recommendations for 2018" below. 

Monitoring Results and 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.




Helge Sierotzki

Syngenta Crop Protection Münchwilen AG 
CH-4332 Stein

Tel : +41 62 866 01 80 
Fax: +41 62 866 07 63

E-Mail: Helge Sierotzki