Lettuce – Botrytis and Sclerotinia

Crop(s):          Lettuce

Disease(s):     Botrytis and Sclerotinia

Resistance Management Strategy for:

Group 2          Dicarboximides; 
Group 7          Succinate dehydrogenase inhibitors (SDHI);
Group 7+11    SDHI + Quinone outside inhibitors (QoI);
Group 7+12    SDHI + phenylpyrroles (PP);

Group 9          Anilinopyrimidines (AP);
Group 11        Quinone outside inhibitors (QoI); 
Group 9+12    AP + PP; and
Group 21         Picolinamide (Qil).

  1. Maintain a cover with protectant fungicide sprays at seven to ten day intervals from planting.
  2. Do not apply Group 2 fungicides more than four times per season, irrespective of the target disease.
  3. Do not apply more than two fungicides containing Group 9 per crop (including Group 9+12).
  4. Do not apply more than three Group 7, Group 11, or Group 21 containing fungicides per crop and no more than two consecutive sprays per crop. If a Group 7 or 11 fungicide has been used solo it should be in strict alternation with other modes of action. If used in a mixture, no more than two consecutive sprays per crop. This includes the treatment at the end of one crop and the start of the next as consecutive.
  5. Group 7 and Group 21 containing sprays should not make up more than one in every three of the spray program.
  6. Do not apply more than two consecutive applications of a Group 12 containing fungicide.
  7. Apply Group 21 as a protectant spray only. Continue alternation of fungicides between successive crops. Do not apply more than five (5) application of Group 21 per year on the same area.
  8. No specific resistance management strategy has been developed for low-risk fungicides, including those in Group M and BM. These products should be included in a management strategy as per label recommendations.
Maximum recommended number of sprays which can contain Group:



Total number of targeting sprays

2 7 (incl. 7+11) 9 (Incl. 9+12) 11 (Incl. 7+11) 12 (Incl. 7+12) 21
1 1 1 1 1 1 1
2 1 1 1 1 2 1
3 1 1 1 1 2 1
4 2 1 2 2 2 1
5 2 1 2 2 2 1
6 2 2 2 2 2 2

URL: https://croplife.org.au/resources/programs/resistance-management/lettuce-botrytis-sclerotinia/
Content last updated: July 14, 2023

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 14 July 2023. All previous versions of this strategy are now invalid.