The curling looks very much like inadvertent damage from herbicides. Any chance of that?

Or any chance of manures in the growing media?

When you pull them out, toss them out. Don't compost them. Toss your plant ties and wash down your stakes, let them air dry in the sun and then store them indoors. Could be a late blight combined with air pollution/stagnant air. Or, you could be spreading it as you walk past one plant to another.

From what is on the ground, it seems this has been shedding for a while so clean all that up and toss it to the trash, not the compost.

Thanks. I'd heard the term 'late blight' but didn't know what it was. I'm reading just now on the web that it was major culprit in the 19th century potato famines, and can affect other nightshades. Thank you.