Please go back to the TAMU site you were at and look at foliage diseases and look specifically at Early Blight ( A. solani) and Septoria Leaf Spot, b'c it's one of those two and since both are fungal foliage diseases you might consider starting a rigorous spray program with Ortho Garden Disease Control which is Daconil,an anti-fungal, which is excellent for both of those diseases.

It's usually used as a prevenatative but can lessen the progression of the fungal diseases.

In my garden Yellow Pear is an absolute magnet for A. solani. Sigh.\\Pictures are static but disease is progressive so it's sometimes hard to make a Dx via pictures.

Carolyn

So either way, you think it's definitely NOT a pest, right? Could you suggest a fungicide that works well for you? Right now I have an organic spray, but I'm not sure how reliable it is (I just picked it up at Lowe's).

No, unfortunately it is a disease. Carolyn already recommended a fungicide for you above. ;) Ortho Garden Disease Control It is also sold as Daconil and other brand names. It is an anti-fungal that works well for both early blight and Septoria.

Dave

Ah, excuse me for being blind. =)

I was reading more about Septoria, and several sites said something along these lines about identifying Septoria:
uniform, small size of the spots (which if you look closely are spore receptacles) and the lack of concentric rings in the spots. The presence of fruiting bodies (the spores) of the fungus, visible as tiny black specks in the centers of the spots, confirms Septoria leaf spot.

I can't see any black marks inside the paler areas, not even tiny ones. Also, the marks are not uniform at all.

In regards to early blight: The classic symptoms occur on the leaves where circular lesions up to 1/2" in diameter are produced. Within these lesions dark, concentric circles can be seen.

This is also not seen on the leaves.

The sites said humidity plays a factor in both early blight and septoria, but especially with early blight (warm air and humidity). However, I live in a desert -Utah- where humidity is about negative 60%. Ok, I exaggerate, but being from Florida, this is what it feels like! This seems to rule out early blight, but supposedly septoria can manifest itself in cooler weather with rain (which has happened here the past week on and off). I would be convinced if only it weren't missing those characteristics mentioned earlier.

Another site said that septoria is often confused with bacterial spot. Since I am not familiar with these things, maybe one of you could confirm if it may or may not be bacterial spot. I'm wondering because the treatment of a fungus is supposedly different than the treatment of a bacteria.

I disagree that Septoria can be confused with Bacterial Spot.

As I said above, pictures are static but disease is progressive so from one picture you aren't going see all that might be described for any disease.

Your foliage is in the early stages and I don't even see any yellow halos that would help ID it.

But Bacterial Spot and Bacterial Speck are very very dark, almost black spots while the fungal ones aren't that dark and the lesions are much more amorphous in shape.

So it's just my opinion but it looks fungal to me and not bacterial.

Carolyn

Ok, sounds good. Thanks, Carolyn. Now about the stuff you were talking about- is it readily available at a place like Lowe's or Home Depot or do I need to go somewhere in particular (or order it online)? I am a container gardener, is it practical for me?