From the rain forecast for this Saturday May 4th, 2019 it appears that we will have another monilinia infection period. From Observations made Thursday May 2nd in the Annapolis Valley, blueberries are still at or approaching the F2 bud stage. With the increasing temperatures over the weekend and next week, the percentage of susceptible F2 buds will quickly increase. Apothecia cups are also still present and sporulating. If you applied a spray for the previous infection period you may still have protection depending on when the application was made and the product used. If you have not applied a spray already, this Friday May 3rd would be an ideal time before the rain begins. I will put out a blog post early next week confirming whether or not there was an infection period.
As reminder the decision to spray should be based on scouting and observation made in your own field as development and weather can vary considerably between fields. For an infection period to occur blueberries have to be at a susceptible bud stage, apothecia cups have to be present, and weather conditions need to be suitable. For more information on blueberries, monilinia, or pesticides please refer to the Management of Mummy Berry Disease in Highbush Blueberry