Apple tree fungus
What can we do about apple tree fugus. We put insect control around the the trunk in the spring and the tree starts out fine. Sure enough after a few weeks the leasves begin to develop a fungus. Now the apples are all falling off prematurely.
Pennington County South Dakota
There are several diseases that are common to apple trees and show up this time of year. Dr. Ball has referenced several in his update, link included below. You will find it informative and perhaps help you to understand the problem and find ways to minimize it or avoid it next year. http://sdda.sd.gov/legacydocs/Forestry/educational-information/PDF/pest-alert-2013-July-24.pdf