Hello -- We just planted a new serviceberry tree (amalanchier autumn...

Asked May 29, 2015, 8:57 AM EDT

Hello -- We just planted a new serviceberry tree (amalanchier autumn splendor). It has suddenly developed a deforming blight on nearly all of the berries and several leaves near the berries. it is a pink/orange canker. Can you advise me on what it is and how to treat? I could snip off all of the berries for this year and apply whatever is needed. thanks for your help! i am really grateful for the expert support through extension.

Ramsey County Minnesota

5 Responses

Serviceberry is in the rose family (Rosaceae) so it is susceptible to many of the same disease and insect pest problems seen in other species within the family (e.g. apples and pears). Your tree may have Cedar-quince rust, Gymnosporangium clavipes. Cedar-quince rusts can infect most varieties of eastern red cedar (Juniperus virginiana) as well as many other junipers and an alternate host. Cedar-quince rust has the broadest host range and can affect many genera in the rose family including apple, crabapple, pears, quince, hawthorn, serviceberry, mountain-ash, flowering quince, cotoneaster, chokecherry, and photinia. Cedar-serviceberry rust affects twigs, buds, fruit and foliage and can disfigure these plant parts or result in witches’ brooms. Your best defense is to identify the rust's alternate hosts, then remove the species from nearby areas permanently. The alternate host are Eastern red cedar (J. virginiana), Common juniper (J. communis), Creeping juniper (J. horizontalis),Rocky mountain juniper (J. scopulorum), and Savin juniper (J. sabina). I am sending you many sites so you can see pictures of the rust on both the serviceberry and the alternate host.

http://www.extension.umn.edu/garden/diagnose/plant/deciduous/serviceberry/fruitdeformed.html

http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/cedar-apple-rust-and-gymnosporangium-rusts/

http://extension.psu.edu/pests/plant-diseases/all-fact-sheets/cedar-apple-and-related-rusts

http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/diseases/rusts/cedar-quince-rust.aspx


Hi Pat -- Thanks so much for your note and the links. we noticed the spots within about 1-2 days of purchasing th eplant --f is it likely they contacted the fungus while at Gertens? We have arborvitae a block away, but no cedar/juniper family trees other than that (i didn't see arborvitae mentioned as yet on the host list). We have a crab apple in the front that is receiving Infuse treatments (for something else that was causing leaf drop)-- would that help the serviceberry as well?

Finally, should i prune off the berries from the serviceberry tree? they seem to be most affected.

thank you!!!
amy

The service berry may have contacted Cedar-quince rust, Gymnosporangium clavipes at the nursery. Prune off and dispose the infected berries so they do not infect a nearby juniper. Arborvitae(Thuja) are not alternate hosts for this disease.

Thanks, that is great to hear. i will prune the berries immediately. Attached if you wish a little thank-you image for your help. amy

Thanks, that is great to hear. i will prune the berries immediately. Attached if you wish a little thank-you image for your help. amy