Mummy berry is a common fungal disease of blueberries. The fungus causes shoots and flower clusters to dieback and fruit to mummify. Mummy berry is caused by the fungus Monilinia vaccinii-corymbosi.
Mummy berry is a disease of blueberry that is spread from infections in both leaves and berries. The mummy berry fungus overwinters on the ground beneath blueberry shrubs. In spring it releases spores from a cup-shaped mushroom. The spores infect and kill emerging leaf shoots, causing the shoot blight (primary phase of the disease).
Blighted shoots then produce a second type of spore that is carried by insects to the flowers, where fruit infection takes place (secondary phase of the disease). The end result is “mummies” – berries that do not turn blue, but instead turn pink or salmon-colored and fall to the ground.
Controlling Mummy Berry
Avoidance Home gardeners can avoid mummy berry by planting only disease-free, dormant plants. This avoids introducing mummies or infected leaf shoots into the new planting.
Sanitation can be used to reduce the incidence and severity of disease by removing or burying the overwintering mummies. Hand raking or the use of a leaf blower around bushes can be used to move mummies to the aisles between rows where they can be disked under or collected with a bagging mower.
Mulching – Mulch applied 3-4 inches deep underneath bushes will prevent mummies from emerging in Spring. Mummies buried at depths of an inch or more are not able to emerge through the mulch layer and are thus prevented from producing spores.
Fungicides – Fungicidal control has proven very successful. Fungicides are used at leaf emergence to prevent primary (leaf shoot) infection, and again during bloom to prevent secondary (flower) infection. Since fungicide labels and recommendations may change, consult annually revised extension publications for specific recommendations, such as the North Carolina Agricultural Chemicals Manual, or the crop-specific management guides at https://smallfruits.org/.
Resistance is the ability of the plant to withstand (resist) infection by a pathogen. IN the western part of NC rabbiteye blueberry cultivars that have shown some resistance to mummy berry include Premier, Columbus and Powderblue.
For the eastern part of NC southern highbush cultivars that have exhibited resistance include Legacy, O’Neal and Star. Resistant northern highbush cultivars include Duke and Elliot.
*Information for this article excerpted from the NC State publication Mummy Berry Disease of Blueberry.
