Here's how the leaves look from a distance.

Here are the brown spots that develop later in the season.

Here's a pic of the back of the leaf with the brown spots. Note, I realize the veins in the photo above are yellow, but there are also leaves where they veins are green and the leaves are yellow... I will take a pic of that asap. Thanks again in advance for any ideas.

This post was edited by zestfest on Wed, May 22, 13 at 3:32

I would say its a disease, nutritional issues don't make spotting like that. The lower leaves are just dead spots, I don't see signs of any spores on those spots. There is a chance it could be black rot, but it could also be some more obscure disease. I don't think its scab. If you sent the lower type of leaf for diagnosis all the spores could have been dead. The upper leaves look like the active infection eating at the leaf.

A few years ago someone had a similar looking thing and there was no conclusion on the diagnosis. I linked the thread below.

Scott

Here is a link that might be useful: old thread

What are you spraying the trees with?

Very grateful for the input, thank you. I spray with horticultural oil and lime sulphur before bud break.

Have you sprayed since the leaves have come out?

Have you sprayed since the leaves have come out?

No, I have not. I'm hoping to get a diagnosis first.

Is it in the ground or a container?

The apples are in the ground. The soil they are in isn't great. It's quite sandy -- it was grass turf that I turned over to make room for the apples.