Hi,
You don't mention if you ever spray your tree for insects and fungus.
You need to be on a regular spray schedule to both keep the tree healthy
and preserve the apples when they come. Try a general orchard spray
from
someone like Bonide, and stick to a schedule of about every 10-14 days.
Wait for a calm day with no rain in the near forecast. Best protection
is a face mask with filters and protective clothing. Look into dormant
oil spraying for next Spring, as well. Don't spray when there are
blossoms on the tree (it will kill all the beneficial bee pollinators).

Sherwin Dubren
MidFEx

Some One wrote:

Hey all!

We planted a "Red Fall" apple tree (about 6' tall) about a month ago.
Tree seems healthy, but we recently noticed that the leaves are
starting to curl up and some have white patches. These patches look
dusty, but aren't. There are also a few leaves that just turn yellow
and come off the tree VERY easily. Finally, I've also noticed some
leaves have some small rust/brown spots.

We're zone 3A in Calgary, Alberta, Canada.

We haven't had much luck finding a decent "plant diseases and pest"
book or website.

Any idea what is happening and how to deal with it?

Thanks!