Cooperative Extension: Maine Wild Blueberries

5.14.16 Mummy Berry Infection period, May 13 to May 14

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Waldo, Lincoln, Knox Counties

I am not sure if you are done yet or not.  We saw numerous spore-producing mummy berry cups at the field in Hope (Appleton) on Wednesday, May 11.  I have no reports of cups from Liberty or other areas.  If you have a wet or slower field you may still have cups around for this infection period.

Hancock and Washington Counties

I have reports of pinheads, immature and mature cups from across these areas on Monday, May 9 and Tuesday, May 10 and reports of new pinheads in East Machias area on Saturday, May 14.   I think there are still active cups in these areas.  With the warm weather, the cups may be finishing up and hopefully will finish up next week.

Please report to me what your mummy berry plot is doing early next week.  I am hoping most things will be drying up.  Contact info: sannis@maine.edu or the Blueberry Hotline 800.897.0757 (in Maine).

Thank you, Seanna Annis 

Infection Period and Fungicide Recommendations

We did have the weather to cause an infection period in all monitored fields except the Waldoboro area.    I suspect we may get another with the wet weather predicted for Sunday.

If you have applied fungicides within seven to ten days before an infection period, your plants are protected.  Some fungicides, such as propiconazole and fenbuconazole, have kickback activity which can kill off the fungus within about 72 hours after it gets in.  Most fungicides recommended for mummy berry have protectant properties and will protect your plants at least seven days after application and depending upon the weather up to 10 to 14 days (check the label).

If you have applied fungicides after May 4 to May 7 (ten to seven days before these current infection periods), your plants were probably protected.  If you have not applied fungicides and wish to, you have up to 72 hours after the infection period start to apply fungicides with kickback activity (fenbuconazole or propiconazole) to protect your plants.   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.