Gee thats odd. Did you open up the leaves to make sure there were no aphids or the like in them? It looks something like some of my cherry leaves that got deformed by leaf curling aphids. If there are none then it does look like some relative of PLC.

Scott

scott my peach leaf curl makes my peach leaves go an ugly orangy red- whereas the leaves in these pics do not appear to have any discoloration.

scott- does your peach leaf curl discolor the leaves?

I'm certain the problem is leaf-curling aphids. Plums and pluots are very susceptible. (The unaffected plum graft on your tree just happened to escape the aphids, I think.)

An application of horticultural oil next winter (just before bud-break, ideally) should result in complete or nearly complete control. However, you're stuck with the deformed growth for this season, unfortunately.

"Flavor Supreme" is known to often be a shy bearer, so grafting Asian plums into the canopy to improve the chances of pollination/fruit-set is a very good idea.

On my cherries I got rid of these leaf-curling aphids by spraying soap, hand opening each leaf to get at all the bugs. It was a lot of work and then you have to keep spraying oil or soap for the next month or so to get the stragglers. I didn't find dormant oil to completely work on them, at least in my climate - last summer was the second or third summer I got them. So this year I am applying prophylactic oil - I am going to spray oil every couple of weeks whether I see any of these critters or not. I am doing the same thing on my persimmon psylla, a similar kind of bug I have not been able to get rid of. So far so good - the only curling leaves I have found were a couple apple leaves, which I promptly pulled off.

LL, indeed curl has those pink/orange/red colors on peaches.

Scott

If you are so inclined, a spray of insecticide will control aphids. These leaves seem unusually deformed. But it is very easy to tell if it is aphids, just look inside the curled leaf.

The fruitnut

Leaf-curling aphids it is!

Thanks for the help