I don't know what that problem is, but if there is only one plant in the picture it looks like you've covered the crown with mulch. You'll want to take the mulch off of the crown, you don't want it actually touching the crown and the stems because it can lead to rot.

I don't think the mulch is a problem. Have you used any herbicides in the area recently?

My guess is a moisture problem. I had a lot of plants that looked like that a few weeks ago after a dryer than normal May. Blueberries don't tolerate dry conditions well. Mulching is going to be a savior for your plants. Get on a thick layer and until you get a few good soaking rains you still may need to water plants to keep them healthy.

Yes, it is only one plant in the pic. No herbicides used. I figured it was something I did cause it seems to be popping up in all the plants that I worked on. I didn't notice this symptom on the other plants that I didn't apply the peat and mulch. I will clean up the crown area. Also, when I applied the peat, I did not water in cause I felt that water was not needed. It seems like it was either from the dry peat or the crown mulching. I decided to add the peat cause the "mound" was lowering. I will clean it up and water to see if it helps. I should have applied the old saying, if it ain't broken, don't fix it. I'm having this problem on two of my toros and two jerseys.

I have the same problem with my eight year old blueberry bush. It produced three pints of blueberries and suddenly all the leaves turned completely brown, and are falling off. It has never happened before. I am growing it in a 20" container and have followed the nurserys advice of feeding it with Mir-Acid once a month from May 1 to August 1. Help!