If your blueberries have never suffered from mummy berry, consider yourself lucky. I don’t know how long some of my plants have been infected, but I spotted it on three of them last year. Part of spotting it was due to the MG training. The other part was that it was really bad on one of the older bushes. There were almost as many mummies as blue fruit. Well, maybe there weren’t that many but there were a lot.
It is caused by a fungus Monilinia vaccinii-corymbosi. The fungus overwinters in the infected fruit (mummies) that have fallen to the ground. In the spring trumpet-shaped apothecia produced on the mummies eject wind borne spores that infect new shoots and flowers. Its all down hill from there.
Cultivating around the plants a minimum of two inches in the spring, or applying two inches of mulch around the plant is supposed to keep the spores from becoming airborne. Picking the mummies off the plants and keeping any that fall on the ground picked up will also help. I’m going to try putting black plastic around the base of the plants, next spring, to see if that keeps the spores from surfacing.
Once you know what to look for, the infected berries are pretty easy to spot. Left picture. When they start to ripen they turn a pinkish beige and start to form ridges like a pumpkin. They then start to shrivel and turn white. Right picture. They then fall to the ground where you can pick them up and dispose of them.
