Glenn:

I guess it could have been your green aphids, but I usually associate that type of damage with mites, of which there are several species. Some mite species are so small as to be barely visible, and operate on the underside of leaves. For some reason, mite damage seems not to result in curling of the leaves.

Not that it makes much difference from a practical standpoint. Your insecticidal soap should also be effective on mites, as would many insecticides and even summer oils.

Mites will also attack many decorative plant species. Last summer, a single boxwood in a row at my son's place appeared to be dying, while all the others were fine. We sprayed with permethrin, the damage stopped, and the boxwood resumed healthy growth. I am pretty sure the cause was mites so small we couldn't even see them.

Don Yellman, Great Falls, VA

I think it is a fungus having no connection with your aphids. Al

Don-
Thank you as always! Googling "apple mite damage", I'm finding a picture that looks almost exactly like mine. See link below. Thanks again!

Calistoga-
I think Don is right in my particular case (as he ususally is)... if you still think it's a fungus, can you give me more specifics? Thanks,
-Glenn

Here is a link that might be useful: {{gwi:119166}}

The photo of blister mite damage, although similar to your photo, doesn't match.

I suggest it's water stress in a young tree -- probably not yet rooted in well.

Apply the majority of water to the area of the original root ball because that area dries out faster than the surrounding soil.

Hi Jean-
Hmmm... To me, it looked like the pictures matched pretty well... In both cases the damaged brown area filled that particular [pixel] of the leaf. (I'm not a biologist... I know pixel is an engineer's word, but I don't know the correct word in this case.) I wasn't able to find anything on Google that matched my pictures better. Were you?
The tree is in very well drained soil. Basically, it's mostly sand under about 6 inches of loam. But, Steven Cummins said this was ideal orchard ground, so I think I'm good there. It is possible that it did get a little dry though in all the hot weather we've had.
-Glenn

You said: "It is possible that it did get a little dry though in all the hot weather we've had."

Yep, it did.

Glenn I admit my eye site is not up to seeing Mites or mite damage, even after having my cataracts removed. Al

Jean:

Hate to disagree with you since you are so often right, but not this particular time. Glenn's own photo of mite damage is of the top surface of the leaf; the photo in the link is the underside. You would have to turn that leaf over to get the best match to his damage.

Around here, on those rare occasions when a fruit tree can't find sufficient moisture in the soil, entire leaves shrivel beginning at the margins. They do not selectively develop brown spots in some areas while the rest of the leaf appears normal.

It's been hot in Virginia too, but the rains have been regular enough that I haven't had to water anything so far, even the blueberries or the vegetable gardens. Rhode Island has received at least as much rain. We have a lot of problems growing fruit here in the east, but it's usually not like the west coast where the rains shut down entirely in summer.

Don Yellman, Great Falls, VA

Hi all again-
We had such good discussion on my first leaf issue, I figured I'd post my other leaf questions. No good deed goes unpunished. :-)

Although not my best camera work, you can see in the first 2 pics below, there is a very uniform ring of leaf damage around the perimeter of the leaf. Normally I'd think this was just some sort of heat/dryness/water-stress damage like Jean was talking about, but this was so uniform that I wondered if it might be something else?

{{gwi:119169}}

{{gwi:119170}}

And, this is just classic heat/dry damage/water stress, correct?
{{gwi:119171}}
Are these all just simple water stress?

Thanks,
-Glenn

Those leaf edges are damaged from rustling. Esp. the new formed leaves. We have had a number of thunderstorms in the Northeast. My loaded Anjou pear snapped off at the graft and it was staked with bamboo.