Re: Apple tree getting white patches under the leaves?

[Sherwin Dubren]

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:

{Morton Arboretum}

and follow the links for plant information.

Hope this helps,

Sherw>

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!

[Pam]

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

Sherw> Hi,

[Pam]

Only good if you buy into Ortho's product philosophy. The AHS and Rodale publish far superior disease diagnostic books for the home gardener without the pesticide marketing angle. Or refer to your own country extension office for disease information and treatment recommendations.

pam - gardengal

[Some One]

Argh!

This sounds like work... : )

Complete newbie to outdoor gardening. Inside we have at least 70+ plants... All they get is water and the occasional fertilizer and they're all healthy. Doesn't it work that way outdoors too???

I didn't plan on doing any spraying on the tree... maybe once it was large enough to worry about getting fruit from it. Right now I just want it to be healthy and grow. I'd pluck off any apples I see started to keep the nourishment inside the tree.

protection

dormant

pollinators).

yellow

pest"

[Marley1372]

To comment on the general orchard sprays- They usually contain one or more insecticides as well as a fungicide. Why spray with one of these when you have no insects prsent? Its a waste of money and bad for the environment.

Toad

[Sherwin Dubren]

Hi Pam, You must live in a very unusual area dormant spray does the job. Here in the Chicago area, if you don't spray on a regular schedule, you loose most of your fruit to things like apple maggots, codling moths, etc., just to name a few.

Sherw>

[Sherwin Dubren]

Again, I would like to know where you live where there are no insects.

Sherw>

[Sherwin Dubren]

Hi Pam, The reason I referred the party to the Ortho book was twofold. One, it has some very nice pictures of attacked trees, which help to identify what is causing the problem. Two, I happen to have that book in my house and am familiar with it. Yes, there are other references, but I wanted to get this person off the starting line.

It is a sad fact of life that the most tasteful apples do not have disease resistance built in. Maybe in the process of developing these disease resistant apples destroys some of the flavor. As I mentioned before, I grow Williams Pride (a disease resistant apple) which is not a bad tasting apple, but it doesn't have the full flavor of one of my heritage apples, Hudsons Golden Gem.

Here in the Midwest (and perhaps elsewhere), we have a big problem with codling moths and apple maggots. I tried spraying with Rotenone, which is made from all natural ingredients. Unfortunately, it did not do the job to stop these pests, plus it kept clogging up my sprayer. To me it is a question of either very tasteful apples, or going the organic/natural resistant path.

Sherw>

[Sed5555]

Could be Wooly Apple Aphids.The aphids and their nymphs are a reddish brown and they produce fuzzy white filaments in patches. The leaves can become yellowed because the aphids are sucking insects that drain the chlorophyll from the them. The small rust/brown spots could be rust (a fungus) or merely the aphids themselves. These aphids are difficult to get rid of because they have a waxy coating that is not easily penetrated. Control usually requires professional application of pesticides. sed5555