Blight on my apple tree
We recently learned that one of the trees in our yard is an apple tree. It has numerous small green apples on it but the leaves have all these yellow/orange spots on them. I’m concerned about what it is and what can be done to help the tree. I don’t like using chemicals, especially on fruit trees but don’t know what I need to do. I’m going to try to attach a picture of one of the leaves. Please let me know what I can do for this tree. It sits by itself in an open area of our yard with grass all around. It’s not more than 15 or so feet tall. I live in Gaithersburg, Md.
Montgomery County Maryland
This looks like a rust disease, cedar apple rust. Cedar apple rust disease alternates between apple and cedars. This fungal disease will also be worse in some years that have very wet weather at crucial times in spring.
In general, apple trees are very susceptible to insect and disease issues and eventually require a spray schedule for control. You can spray the apple for rust but not the cedars. See cedar apple rust on ornamentals. http://extension.umd.edu/hgic/rust-diseases-trees-and-shrubs
See cedar apple rust on apples and a spray schedule from VA Tech. It is too late to spray this year. You will have to begin next spring. The best recommendation is to plant resistant varieties of apples.