So, I have a bunch of these in a row, and, all of them but two did pretty well over the summer. However, two of them died. The pattern looked like this picture, starts from the center of the leaf, then, spread outwards until it is completely brown.

I replaced those two, and, one of them is doing fair, the other is the one in this picture, I suspect it is also going to die.

So, this is irrigated like all others with a single dripper, adjustable, which runs 10 minutes every 3 days. Unless it rains of course. I have adjusted it to put out what I think is the right amount of water. Today, the day after watering, I dig around the root ball, all the way to the bottom, and, it's moist, but not wet. Not soaked by any means. Not dry either. Seems right to me.

When I dug out the old one, it was not standing in water or anything like that, so, should not be a case of over watering.

Used root stimulator from the nursery per directions.

Some disease of some sort? Doesn't look like Anthracnose. No idea what Fire Blight looks like. These are the variety Red Bird.

The affected bush, as shown in the picture, is lighter green than the non affected bushes.