This is totally unnecessary for a home fruit grower and can be downright
dangerous. Powdery mildew (which the problem certainly sounds like) does not
require treatment - I have a Gravenstein apple which is a powdery mildew
magnet and get bumper crops of perfectly unflawed apples each year. If any
spraying of fruit trees is required, a dormant season spray will control
overwintering pests and insect eggs as well as smothering of fungal spores.
Best to research and purchase fruit trees which tend to be more resistant to
fungal problems like scab or mildew or live with the problems, which for the
most part are cosmetic and have little effect on fruit production.

pam - gardengal



Sherwin Dubren wrote:

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!