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.