Do I cut and burn or will my applw trees survive?

Asked September 24, 2017, 5:43 PM EDT

I have an orchard of about 75 trees of varying species. The trees in question were planted in the spring of 2015. They were XXL in size and were purchased from a nursery in WI (they obtain the trees through Bailey's). There are 4 trees planted in a row that are turning black. All 4 trees are "Gravenstein" apple trees. I read today that they are highly susceptible to Fire Blight. Do I cut and burn them? Do you think I have any recourse with the nursery that sold them to me? They otherwise look healthy and have been well cared for. I have attached a photo of one of the trees.

Washington County Minnesota apple diseases

2 Responses

The black soot on the tree trunk does not look like fire blight.
https://www.extension.umn.edu/garden/yard-garden/trees-shrubs/fire-blight/
The material on the branches is sooty mold, It is not a disease but it is a fungus. It requires no treatment for the fungus itself unless it blocks so much of the sun that it interferes with photosynthesis. It often will fall off during periods of dry weather.
There are insects that suck sap from trees that leave their waste -called honeydew- on the trees. The honeydew is the breeding and life support for the fungus you see. For that reason,the mold is a sympton of the problem. Identifying and erradicating the insects will prevent more mold from growing.
Read more about it here:
http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/sooty-mold/

One more note thank you for the photo, it was very helpful.