Forgot to mention,

Ortho makes a good book on plant diseases for the home garden,
which includes fruit trees. There should be plenty of material on the
Web, if you plug in 'fruit trees' 'diseases' 'spraying' etc. Also, try
and find if a local University extension service or Botanical Garden
has a Web site. Here is one nearby me in Illinois to try:

http://www.mortonarb.org/ {Morton Arboretum}

and follow the links for plant information.

Hope this helps,

Sherwin Dubren

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!