Cooperative Extension: Maine Wild Blueberries

5.18.15 Mummy Berry Infection periods, May 18

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Hancock and Washington Counties

I have heard from a variety of growers and sounds like cups are drying up in some areas BUT are still active with pinheads and mature spore-producing cups in other fields.  Whether there are still cups in your field, likely depends upon how far along your field is and how much rain your field got in the last week.  I do think there are still spore-producing cups in many fields in Hancock and Washington counties.

There were infection periods throughout this area overnight (see chart below) and the weather forecast is for more wet weather starting tonight and continuing through Tuesday night.

If you have applied fungicides after May 8 to May 11 (ten to seven days before this infection period), your plants were probably protected through this last infection period.  If you have not applied fungicides, you have up to 72 hours after the infection period start, which is the evening of Wednesday, May 20, to apply fungicides with kickback activity (fenbuconazole or propiconazole) to protect your plants.

You should consider that if your plants are in bloom you should avoid applying fungicides during bloom if at all possible to protect pollinators and avoid affecting your pollination.

If you are applying a second or third application of fungicide, it would be good to rotate to a fungicide with a different mode of action or at least a different chemical to avoid fungicide resistance developing in your field.

Thank you to everyone who has contacted me about their mummy berry plots.  Please continue to let me know what your mummy berry plot is doing since we are coming close to the end of the season.

Contact info: sannis@maine.edu or the Blueberry Hotline 800.897.0757 (in Maine)

Thank you, Seanna Annis