Spore release cups growing out of blueberry mummy

Mummy Berry Fungus Forming Inside Berry

Four to seven fungicide applications are made per blueberry acre for control of nine diseases of which mummy berry disease is major. The fungus that causes mummy berry overwinters in shriveled mummified blueberry fruit on the ground. In early spring, cup-shaped structures of the fungus grow on mummified berries. Each cup-shaped structure produces an average of 61,000 spores a day for 9 days. Spores infect young developing twigs and flowers. Fungal tissue colonizes the developing berry. Infected berries turn a cream color and begin to dry (mummify); the mummy retains a shape similar to normal fruit and is composed primarily of fungal tissue.

“Mummy berry disease, caused by the fungus Monilinia vaccinii-corymbosi, is a major disease confronting blueberry growers in North America. …Most losses associated with the disease are due to the rejection or downgrading of commercial blueberry shipments that contain mummified fruit.

Management of mummy berry disease requires repeated applications of fungicide from vegetative bud break through the end of bloom in order to mitigate both shoot blight and flower infection.”

Authors: Tarnowski, T. L., A. T. Savelle and H. Scherm.
Affiliation: Department of Plant Pathology, University of Georgia
Title: Activity of fungicides against Monilinia vaccinii-corymbosi in blueberry flowers treated at different phenological stages.
Source: Plant Disease. 2008. 92[6]:961-965.