Possible mummy berry infection in midcoast region April 19, 2022
Midcoast
Plants were at approximately 20 to 30% depending upon the field, Waldoboro, Warren, Hope, and Searsport on Sunday April 17th. Monilinia cups producing infective spores were present in two fields that were checked on Monday and present in 4 out of 5 fields checked today. The wet conditions on Tuesday April 19th starting approximately 6 to 7am could have caused a Monilinia infection in early fields with a history of mummy berry disease and 30 to 40% of their flower buds at F2. Please check you field by looking at 10 to 20 random stems across the field for their flower bud development.
Please reference the 2022 Fungicide Chart for product options. Some fungicides, propiconazole and fenbuconazole, have some activity to control very early infections. If you apply these fungicides in approximately 72 hours from the start of an infection period, April 19 6 to 7am, you may get some control. Applying fungicides as protectants before an infection period is a more reliable method to ensure you have protection of your plants before infection periods. The next rain period is forecast for next week for the midcoast region.
Downeast
Fields in the Downeast region (Hancock and Washington counties) are starting to get some plants with F2 buds. Fields in Ellsworth/Hancock, Eastbrook, Montegail and Jonesboro all had under 25% F2 on Monday April 18th. New pinheads and one cup were seen in Eastbrook field on Monday. There is rain forecast for Thursday night. If you have an early field with a history of mummy berry, I suggest you check your bud development and whether the buds will be at 30 to 40% F2 by Thursday. This level of bud development will expose enough tissue that some plants may become infected with Monilinia.
Please let me know how your plants and mummy berry plots are coming along. Seanna Annis at sannis@maine.edu.