Mummy berry infections likely later this week, April 28

There have been mixed reports of plant development  in blueberry growing areas. While some fields are past 40% F2 in the Midcoast and Downeast, there are other fields that are not there yet.  There are also reports of pinheads to cups in many fields in the Midcoast and Downeast.  We are getting warmer weather today (Tuesday) and on Wednesday and which will move development of the plants and mummy berry fungus along.  I think it is very likely we will have spore producing cups in most fields later this week.   We are forecast to have possibly one to two days of rain starting Thursday in blueberry growing regions.  I strongly urge you to check your field for plant development.  If your buds are close, you may get infection over this next rainy period. To check your plants, look at stems across your field to see what the bud development looks like. The most accurate method is to collect 20 stems and rate and count all of the flower buds and calculate your percentage of buds in F2 or over.

Picture of developing flower buds. Flower buds are susceptible to the mummy berry fungus once they have separated enough to look like small crowns.

 

 

 

 

 

 

 

Please note the range of dates from these field observations!

Location Date checked  Mummy berry plots Plant development 
Brunswick 4/22/2020 nothing F1 last week
Waldoboro 4/27/2020 pinheads some F2
West Rockport 4/26/2020 nothing About 15% F2
Hope/Appleton 4/23/2020 cups and pinheads about 15% F2
Liberty 4/26/2020 cups some F2
Searsport 4/23/2020 pinheads close to 30% F2
Ellsworth/Hancock 4/23/2020 had pinheads close to 20% F2
Deblois/Airport 4/28/2020 pinheads >20% F2
Montegail 4/28/2020 no pinheads 30% F2
Jonesboro 4/28/2020 pinheads 60% F2
Whiting 4/26/2020 pinheads some F2
Crawford/Love Lake 4/28/2020 pinheads very few F2