There is potential for another infection period due to the rain forecast for Tuesday night (May 7th). From observations made Monday May 6th some varieties of blueberries plants have reached majority F2 bud stage, and apothecia cup are still present but beginning to dry up. If you applied a spray for mummy berry before the rain on Saturday, you should still have protection for this infection period depending on the product used. If you have not applied protection for mummy berry up to this point, during the day Tuesday May 7th would be an ideal time. If you are not able to get a spray on Tuesday before the rain, protection can still be achieved by using a product with back action (Topaz, Mission, etc) if applied within 72 hours of the start of the infection period. For more information on blueberries, mummy berry disease, and fungicides refer to Management of Mummy Berry Disease in Highbush Blueberry.
As a reminder the decision to spray should be based off of observations from your own field, as development and conditions can vary widely depending location and other factors. Infection period can only occur when blueberry plants are at a susceptible bud stage, mature apothecia cups are present, and condition are conducive for disease to develop. These recommendations are based off of a location in the Annapolis Valley and may not be applicable to other sites and regions.
