Don't know.

Need clear images

picture of problem? Ken do you have a clue?

This post was edited by campv on Tue, Oct 21, 14 at 17:05

In your zone an Asian shouldn't have lost it's leaves already. Mine haven't. I don't know what's going on. My first thought is fire blight but your symptoms don't really match very well. I'd cut that branch off and see what happens next yr.

Thanks fruitnut
The leaves just turned yellow and dropped like they always do but it was 3 weeks ago and way too early. I know its not fire blight had that on another tree in Ca.
Do you think it might be some kind of borer? Should I dig w/a knife around the split a little to see what's going on before cutting off the branch? I hate to loose the branch
Thanks again I knew you would help

A borer in one branch won't explain why it dropped it's leaves early. Earlier than normal leaf drop is a troubling sign. Are you sure there isn't something else going on like pocket gophers? Is the tree solidly rooted down? Is it way drier or wetter than normal?

We had a ton of rain this monsoon more than usual. I can't see anything going on around the base. Here in northern AZ gophers are rare, unlike Ca. were they build condos.
If the leaves had turned brown or black and dropped then I would have something to go on, but they just turned that beautiful yellow. The branches look good and pliable except for that one spot. I also noticed around the base where the suckers come up that there are two 2"suckers with green leaves on them.
I am at a loss. Hope the tree is not stressed because I want to spray some "Bonide sulfur fungicide on it along with my nectarine. Thanks