What is wrong with my blueberry plants

Asked May 5, 2017, 2:14 PM EDT

I was looking at my blueberry plants today and noticed some of the fruit flowers had a grayish powdery spots, were wilting and turned brown. Out of my eight plants I have Chandler, Liberty, and Elliot varieties. It appears that it's only affecting the Chandler variety (Which are planted in a line 4ft apart). I started searching the internet to find similar pictures and to me it appears that this is Mummy berry. Additionally about two weeks ago I noticed what I thought was just mushrooms (a fungus) growing in the blueberry bed. They were tube like shaped, light brown, and clumped together near my affected blueberry bushes. I have seen this before over the past couple of years and have not thought much about it until now. I have also noticed that the blueberry plants that I found this on have not grown much over the past three years since I planted them. Everything I read about mummy berry says that I should remove the plants. Just wanted to know for sure what I have going on with my blueberries and whether or not I should remove only the affected the plants or all the plants. I have cut off the affected parts of the plant and place them in a ziplock bag. If it cannot be identified from the attached pictures is there anywhere that I can take the samples so somebody could possibly identify this for me?

Linn County Oregon

1 Response

Hello,

First of all great pictures! However, it's impossible to conclusively identify a disease from pictures. Unfortunately, there are four diseases that have almost identical symptoms: 1) mummy berry [only at first stage of infection]; 2) pseudomonas bacterial blight; and 3) botrytis or gray mold; and 4) Blueberry Shock Virus. You can find descriptions of all of these at the PNW Disease Management Handbook web site: https://pnwhandbooks.org/plantdisease

In your pictures you can definitely see symptoms of botrytis on the flowers (gray mold). However, this disease is also ppportunistic and may be coming in on tissue that is already dead (caused by some other disease) -- this is quite common. With that said, it could simply be that some of your flowers are dead because of botrytis. It has been VERY rainy and I would expect that. While I cannot be certain of this without proper diagnosis, I do not think the symptoms look like blueberry shock virus (as too few flowers in an area of the lateral are affected). It is possible that this is pseudomonas (Chandler is particularly sensitive). I do not think it is mummy berry based on these pictures (you would see leaf blackening, not flowers). The mushrooms you describe do not sound like any pathogen associated with blueberry -- they might just be growing in the organic matter near the plants.

Again, the mushrooms can be identified if you are concerned. Also, if you are concerned about these symptoms and want a conclusive diagnosis, you can go to your local OSU Master Gardener office and they will help you submit a plant sample to the OSU Plant Clinic. Note that this has been a bad, wet spring which has fostered disease.
I would NOT take the plants out as any of these diseases are relatively common and none of them require plant elimination as control.
If you have any more questions, contact the MGs and they can assist you.