Cooperative Extension: Maine Wild Blueberries

5.05.14 Mummy Berry Infection period has Occurred

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Lincoln, Knox and Waldo Counties

There are mature cups producing spores in fields in these counties.  There was an infection period in these counties from the evening of Saturday, May 3 through to Sunday, May 4 and some fields may have experienced a second infection period from Sunday, May 4 afternoon to overnight. Please see the table below for infection period start times.  Most plants in these areas now have enough susceptible tissue to need a fungicide application for protection if you use fungicides.  Most fields have flower buds > 40%  by now.

If you have applied fungicide on or after Saturday, April 26, your plants were protected during the infection period this weekend.  If you have not applied fungicides, you have until the evening of Tuesday, May 6 in most areas to apply fungicides, (propiconazole or fenbuconazole) to kill any infection.  Other fungicides should be applied as protectants and before infection periods occur.

Hancock and Washington Counties

There are mature cups in many fields in these areas.  There were conditions for an infection period, but whether you had one in your field depends upon how far along the plants are.  You will need to check your plants to see whether you need to make a fungicide application. The best way to do this is to collect a minimum of ten stems across your field and count all of the flower buds to see how many are at F2.  If there is greater than 40% at F2, you probably have enough susceptible tissue to warrant a fungicide application.

Please see the table below for infection period start times.  Most infection periods started in on Sunday, May 4.  If you have applied fungicide on or after Sunday, April 27, your plants were protected during the infection period this weekend.  If you have not applied fungicides, you have until the evening of Wednesday, May 7 in most areas to apply fungicides, (propiconazole or fenbuconazole) to kill any infection.  Other fungicides should be applied as protectants and before infection periods occur.