Blueberry Mummy Berry: A Destructive Disease
Blueberry mummy berry is a fungal disease that can devastate blueberry crops if left unchecked. It is caused by the fungus Monilinia vaccinii-corymbosi, which overwinters in mummified blueberries on the ground.
Signs and Symptoms
The first sign of blueberry mummy berry is browning along the leaf veins on new leaves. These leaves will wilt and curve, and a light gray powdery mat of spores will develop at the base of the leaf. These spores can infect flowers and fruit, causing infected berries to become slightly ridged, rubbery, and a pinkish tan color. The interior of the berries will contain a gray fungal mass. Eventually, the infected berries will fade, shrivel, and drop to the ground. Once the exterior of the fruit sloughs off, the infected berries look like small black pumpkins.
Lifecycle of the Blueberry Mummy Berry Fungus
The blueberry mummy berry fungus overwinters in mummified blueberries on the ground. In the early spring, as the leaf buds begin to open, tiny, trumpet-shaped brown mushroom cups begin to protrude from the dried-out blueberries. These mushroom cups release spores that are carried by the wind to leaf buds, where they can infect new leaves.
Control Measures
There are several ways to control blueberry mummy berry:
Cultural Practices:
- Plant resistant blueberry varieties.
- Thoroughly rake under the blueberries in the early spring prior to bud break to remove as many mummified berries as possible.
- Apply a couple of inches of mulch to bury any remaining fallen mummies.
Chemical Control:
- Apply urea, lime sulfur, or a concentrated fertilizer beneath the blueberry bushes to “burn” out any exposed mushroom cups.
- Apply fungicides at primary infection, early in the spring at bud break. Reapply the fungicide every week, or as directed by the manufacturer’s instructions.
Impact of Blueberry Mummy Berry on Blueberry Yield
Blueberry mummy berry can have a significant impact on blueberry yield. Infected berries are unmarketable and can reduce the overall yield of the crop. In severe cases, the disease can destroy an entire blueberry crop.
How to Prevent Blueberry Mummy Berry
The best way to prevent blueberry mummy berry is to implement a comprehensive disease management program that includes cultural practices and chemical control. By following these practices, you can help to protect your blueberry crop from this destructive disease.
Additional Tips
- Keep a close eye on your blueberry plants for signs of mummy berry infection.
- If you see any infected berries, remove them immediately and dispose of them in the trash.
- Do not compost infected berries, as this can spread the disease to other plants.
- Clean your gardening tools and equipment after working with infected plants to prevent the spread of the fungus.
