We have not had a major freeze on our rabbiteye blueberries, and I am hopeful that cold damage will be minimal this year. Cold damage (even a light frost) substantially increases the likelihood of mummy berry disease. However, even without cold damage, we still have rainfall and temperature conditions that can combine to increase infection levels. This chart is from a Maine fact sheet for wild blueberries; it might not perfectly apply in south Georgia, since our blueberry species and local Monilinia populations might respond differently. However, the relation between temperature and moisture is likely a somewhat universal one. Bottom line: rainfall and temperatures may move us into the high infection category this week or next, so having fungicides on target will be critical to management of this disease.

Mummy Berry Moisture Temperature Relationship