Cooperative Extension: Maine Wild Blueberries

Wild Blueberry Newsletter – May 2014

May 2014

Mummy Berry and Botrytis Blight Scouting

Mummy berry disease can cause serious loss of yield by blighting the developing leaves and flowers. By the time you see the damage to the plants, it is too late for control. If you have had this disease in the past, then protective treatments need to be applied to prevent injury. For details see Wild Blueberry Fact Sheet No. 217, A Method to Control Monilinia Blight, https://extension.umaine.edu/blueberries/factsheets/disease/217-a-method-to-control-monilinia-blight/ .

In the last two years, we also saw Botrytis blossom blight during bloom in some areas.  The Botrytis fungus attacks a wide variety of plants and is not as predictable as mummy berry disease on when and where it will occur.  Even if you have wet weather during bloom, you may have no Botrytis disease if the fungus is not in your field.  The best way to tell if your field is at risk is to scout early blooming blueberry clones and dying leaves and flowers on weeds in your field.  If you see dead flowers or leaves with black hairs sticking out of them (you will need a hand lens or magnifying glass to see them) then you have the fungus in your field.  To protect against Botrytis you need to apply fungicides when you see symptoms on early blooming clones. Be careful to protect pollinators and do not apply fungicides when they are in the field.  For more information see Wild Blueberry Fact Sheet No. 212, Botrytis Blight Control for Wild Blueberries,  https://extension.umaine.edu/blueberries/factsheets/disease/212-botrytis-blight-control-for-wild-blueberries/.

Seanna Annis has deployed more weather stations for better coverage of the state this year.  Information on the progress of the mummy berry and Botrytis blight at the monitored sites and suggested timings for fungicide treatments will be sent to growers on our email list. You can also call our toll free line for information, 1-800-897-0757 and press 3, or you can find information on our Wild Blueberry Blog at https://extension.umaine.edu/blueberries/blog/.

Once bloom occurs, you can scout your fields to look for blighted leaves and blossoms to get an indication of how well your treatments worked for mummy berry and if you have Botrytis present and to assess the potential for disease pressure in the next crop year.   We will be discussing this at our next ICM workshops (see the April Wild Blueberry Newsletter or Calendar of Events at https://extension.umaine.edu/blueberries/calendar-of-events/) .

Pollinator Workshops for Wild Blueberry Growers – Reminder

Frank Drummond will be conducting  workshops designed specifically for wild blueberry growers and will provide instruction on bee identification and how to estimate bee density and fruit set so that you can determine if you are getting adequate pollination. The workshop will also include information on strategies to improve habitat for wild bees as well as the proper use of insecticides to minimize bee mortality.  Since these workshops require good weather, we will have a rain date also scheduled for each workshop.

Schedule for Pollinator Workshops:

Seven Tree Farm (Dorothy Dolham, Route 235, 2740 Western Road, Warren, Maine)
Date & Time:	Tuesday, May 27, 2014 from 4:00-6:00 p.m.
Rain Date & Time:	Tuesday, June 3, 2014 from 4:00-6:00 p.m.
Blueberry Hill Farm (1643 Route 1, Jonesboro, Maine)
Date & Time:	Wednesday, May 28, 2014 from 4:00-6:00 p.m.
Rain Date & Time:	Wednesday, June 4, 2014 from 4:00-6:00 p.m.

If you have questions, please email Kourtney Collum at kourtney.collum@maine.edu