Canola – Blackleg and Sclerotinia

Crop(s):          Canola

Disease(s):     Blackleg and Sclerotinia

Resistance Management Strategy for:

Group 2               Dicarboxamides;
Group 3               Demethylation Inhibitor (DMI);
Group 7               Succinate dehydrogenase Inhibitors (SDHI);
Group 7+3          SDHI + DMI; and
Group 11+3        Quinone outside Inhibitor (QoI) + DMI.

  1. Fungicides should be used primarily as a preventative or at first sign of disease. If disease is established within the canopy, fungicides may not produce optimal results and there is very strong potential to select for fungicide resistance. Sclerotinia targeted applications should be applied during flowering of the crop, prior to an infection period. Applications of fungicides for Sclerotinia may put selection pressure on the blackleg population.
  2. In high risk disease environments, integrated management approaches should be used to reduce fungicide resistance risk including growing canola at least 500 m from previous seasons canola stubble, the use of resistant varieties, using alternative fungicide modes of action and stubble management such as knocking down and/or strategic burning.
  3. The risk of developing resistance to fungicides can be reduced by incorporating different modes of action into blackleg management programs as either mixtures, co-formulations or rotations.
  4. If a Group 7 seed treatment has been used with foliar activity on blackleg (as determined by label claims), the seedling fungicide application at 4-6 leaf stage targeting blackleg should not contain a Group 7 fungicide.
  5. DO NOT apply more than two applications containing Group 7 fungicides per growing season. Combinations of in furrow and seed treatment are counted as one application.
  6. DO NOT apply more than two consecutive applications of a Group 3 fungicide.
  7. Minimise use of fungicides which are known to have compromised resistance status.
  8. If seasonal conditions require a second fungicide application at 50% flowering after a 20% flowering timing, the second application should be from a different Group.

 

Application stage (Disease being controlled) Rotation options for different fungicide active groups
Seed dressing & in-furrow (Blackleg)

 

None None None None 3 3 3 3 7 7 7+3 7+3
Seedling foliar (Blackleg)

 

None 3 7 7+3 None 3 7 7+3 None 3 None 3
20-50% flowering (Sclerotinia)

Choose only one option from this section

          1 None None None None None None None None None None None None
2 2 2 2 2 2 2 2 2 2 2 2 2
3 3 3 3 3 3 3 3 3 3
4 7+3 7+3 7+3 7+3 7+3 7+3 7+3 7+3 7+3
5 11+3 11+3 11+3 11+3 11+3 11+3 11+3 11+3 11+3

If a second application at 50% flowering is required:

 

  Application at 20% flowering
Group 2 Group 3 Group 7+3 Group 11+3
Rotation options for 50% flowering second application              3 2 2 2
7+3
11+3

URL: https://croplife.org.au/resources/programs/resistance-management/canola-blackleg/
Content last updated: June 10, 2020

CropLife Australia’s Resistance Management Strategies provide a guide for crop protection product rotation through product groups. The strategies are a useful tool that supports farmers’ adoption of resistance management. All crop protection products must be handled and applied strictly as specified on the product label or APVMA permits.

These Resistance Management Strategies do not replace product labels. They are a guide only and do not endorse particular products, groups of products or cultural methods in terms of their performance. It is important to check with the Australian regulator’s (APVMA) product database for contemporary information on products and active constituents. The database can be sourced through www.apvma.gov.au

The information given in this strategy is provided in good faith and without any liability for loss or damage suffered as a result of its application and use. Advice given in this strategy is valid as at 10 June 2020. All previous versions of this strategy are now invalid.