Possible Monilinia infection this weekend in early fields, April 21, 2023

The Monilinia cups are starting to develop.  I think we are at early stages but if you have an early field you may have a Monilinia infection period over this weekend.  I have a report of pinheads and a cup in Appleton, and pinheads in  Whiting/East Machias along the coast and Pike Brook on the barrens.

The plants are developing quickly in some early fields.  Please check your plants.  If they are approximately 30 to 40% F2 (T2, see pictures below) ,they are now susceptible and you have enough exposed tissue on your plants to make fungicide applications advisable.   The weather forecast indicates rain on Saturday night through Tuesday that may bring an infection period to early developing fields if there are active Monilinia cups in those fields.

You can look at the phenology tracker on the Wild Blueberry tools website ( https://extension.umaine.edu/blueberries/tools/ ), to get a rough idea of how fields in your area are developing.

Please follow the Pesticide recommendations and consult with your processor before you apply fungicides. (https://extension.umaine.edu/blueberries/wild-blueberry-pesticide-charts/)

Please contact me if you have any information on how the plants in your area are progressing and if you have a mummy berry plot.

Thank you, Seanna

Blueberry flower buds showing F3 on top and F2 at lower buds, leaf buds at V2
Blueberry stems showing flower buds at F2 (top buds of stems) and F1 (lower buds on stems).