Swollen diseased blueberries

Mummy berry (Monilinia vaccinii-corymbosi)
University of Georgia Plant Pathology, University of Georgia, Bugwood.org

Updated: June 14, 2021

Mummy berry a blueberry disease

  • Mummy berry is the most destructive disease affecting blueberries, but it may not appear until many years after planting; after it appears, control measures will be needed every year.
  • The first symptoms develop before bloom, when twigs, leaves, and flower buds wilt, die, and turn brown. In wet weather, brownish-gray fungus spore masses develop on blighted parts. As harvest approaches, infected berries fail to color normally, turn pale pink to tan, are very lightweight, and fall off early.
  • The fungus pathogen overwinters in mummified berries on the ground. During the early spring, just as blueberry leaf buds begin to open, small (1-inch tall), trumpet-shaped, brown mushroom cups begin growing from mummified fruit; spores from these mushrooms cause infections of the young plant tissues. 

Management 

  •  Sanitation. Collect and remove any mummified fruits from under blueberry bushes by thoroughly raking the area in early spring before the buds break. This practice can effectively control mummy berry disease without the use of fungicides. Plant resistant varieties. 
fungal spore cups on the ground from mummy berry
Mushroom cups begin growing from mummified fruit fallen on the ground 
Photo: UGA Plant Pathology, UGA, Bugwood.org