Cooperative Extension: Maine Wild Blueberries

4.21.17 Mummy Berry Season is Starting for Some Fields

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I have reports of mummy berry plots showing pinheads in multiple fields in the Midcoast region (Liberty, Appleton, West Rockport), and in Ellsworth, Hancock, and Jonesboro, Washington counties.  Pinheads are the stage before the cups appear. We have one report of a single cup in West Rockport.  In fields we checked yesterday, plants in West Rockport  (Knox) and Searsport (Waldo) had close to 40% of their flower buds at the F2 stage (crown stage).

I think we are at the very beginning of the mummy berry season in the Midcoast counties. You should count your flower buds to see what stage the plants in your field are. Different parts of the field, depending upon the blueberry clones, the landscape around the plants, and what direction the field is facing can have very different levels of development. To get a good sample, collect ten (or for a better estimate, 20) stems across your field from different clones. You can make a quick guess of their development by looking at the top flower buds. The best method is to rate all of the flower buds and calculate the percentage of total flower buds that are at F2. Flower buds start to become susceptible at the F2 stage.

The weather is supposed to be wet, but cold, tonight through to Saturday or Sunday in most blueberry areas.  The cold weather means a longer period of leaf wetness would be required to cause an infection. I think there is a low risk of infection in most areas.

If you have a mummy berry plot or check on your plants, please send me an email, sannis@maine.edu or give me a call at 207.581.2621 and let me know what stage your field is.  This information helps me determine when I should be considering an infection event may be happening in your area.

– Seanna Annis