Notes on Blueberry Diseases
Mummy berry
Identification
Mummy berry causes two types of symptoms on blueberry shoots and fruit.
Infected shoots turn brown and wilt and infected fruit turns pinkish-white
and hard, and falls to the ground.
Mummyberry fruit
Mummyberry shoot blight phase at bloom
Period of activity
The disease overwinters on the ground in fungal structures or mummies,
which are hard, dark pumpkin-shaped structures about the size of a blueberry.
In spring, the mummies develop trumpet-shaped cups that produce spores.
The spores are released into the air around bud break. Primary infection
occurs when these spores infect new shoots and leaves. Infected shoots
suddenly develop a blighted appearance.
Infected tissues produce a second type of spore, which is spread to healthy
flowers. A secondary infection forms at the base of the flower where the
berry will develop. Infected berries develop normally at first but begin
to turn pinkish or whitish-grey, harden and fall to the ground at harvest
time.
Mummifed bluberries and spore producing apothecia which
appear in the spring
Management notes
Certain varieties like Blueray seem more susceptible to mummy berry than
other varieties. The disease is worse in low-lying areas or beside windbreaks
where there is little air movement. Destruction or burying of the mummies
in the ground before they produce the trumpet-shaped fruiting structures
achieves control. Fungicides are used to protect buds from primary infection.
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