My guess would be Early Blight. The darker lesions with a yellow halo is typically what I would look for with this disease. As it progresses the entire leaf becomes affected.

bump

Marv, I've looked at the picture several times and just cannot be sure of what I'm seeing since the magnification is not high enough to see the interior of the spots I see.

And there may be more than one foliage infection as I see it. The small ones with yellow halos could be Early Blight, as mentioned above, but the larger spot and the expanded ones along the leaf margin could be Septoria Leaf Spot, both fungal, but I can't see the interior structure,

Most of the time the two bacterial ones don't show yellow halos.

Is it the lower leaves or higher up where you see the first signs of infection and I ask b'c that would make a difference as to splashback reinfection from a prior year or a new infection.

Do you spray a good anti-fungal prep as a preventative?

THE products used to help prevent bacterial foliage infections that are available tohome growerfs are not all that effective but would include a copper product or Mancozeb.

Not much help on my part but I wanted to let you know that I had looked at the picture and can only offer suggstions, but not confirm any specific Dx.

Carolyn