service berry fungus on fruit

Asked June 10, 2018, 5:50 PM EDT

My service berry had a lot of fruit this year which were eaten by birds. All the left over fruit are now covered in fine yellow fungus hairs and nobody is eating them. What is it? Will it damage my tree? Should I cut them all off so not to damage the tree and spread whatever this is??

Baltimore Maryland disease issues fruit rust trees

1 Response

This is a fungal disease called cedar-quince rust, Gymnosporangium clavipes. We are getting a lot of reports of rust disease this year, as our weather has been favorable for it. Serviceberry is in the rose family, so it is susceptible to many of the same disease and insect pest problems that are seen in other species within the family (e.g. apples and pears). The alternate hosts of this disease are Eastern red cedars (Juniperus virginiana), Common juniper (J. communis), and Creeping juniper (J. horizontalis). The fungus carries out its lifecycle between the two host plants.
If it is possible to remove Junipers in the vicinity, that can help to control the rust on your serviceberries. Often this is not feasible. Prune off and dispose of the infected berries to help control the spread of the fungal spores. That is really all you can do.