Mummy Berry 2019 #5

Friday, May 10, 2019

There is a high likelihood of an infection period during the rain forecast for Friday May 10, 2019 and Saturday May 11, 2019. Rain is also forecast for the majority of next week, and could result in several infection periods. From observations made in the Annapolis Valley some blueberry varieties have reached the majority F2 bud stage, or are more advanced. Mature apothecia cups are also still present, and although some apothecia cups had started to dry up the forecasted wet conditions could slow this process.

Apothecia cups from May 9, 2019

Bud stage from May 9, 2019 

If you applied a protective spray for the infection period Tuesday May 7, 2019, you should still have control until early next week. If you did not apply a protective spray you should still be able to achieve control during the infection period this weekend by applying a spray before the rain on Friday May 10, 2019. If you are unable to get a spray on Friday you can still achieve control by applying a product with back-action capability (Topas, Mission, etc) if applied within 72 hours of the infections period. If you have already applied one of the back action products twice consecutively a non-group 3 fungicide should be used for resistance management. For more information on highbush blueberries, mummy berry disease, and fungicides please refer to Management of Mummy Berry Disease in Highbush Blueberry

As a reminder these recommendation are based off of observations made at a site in the Annapolis Valley, and may not be applicable to your specific field. The decision to spray should be based off scouting and observation made in your own field. Infection periods only occur when blueberries are at a susceptible bud stage, apothecia cups are present, and weather conditions are suitable. I will put out another update this coming Monday May 13, 2019.