I finally dug up the "affected plants. They were all but dead. They had showed no new growth at all and the few tomatoes that were on them started turning red. Not from ripening but because the plant was dead. I did have one "recover" by sending out a sucker that has now become the plant as the original plant is still sick looking. I believe that the whole problem was a potassium deficiancy because the one plant that "recovered" had a banana peel buried next to it when I originally planted it. It probably started to decompose at just the right time for the plant to benefit from. The rest of my efforts seemed to be too late for thse plants but I hope will stave off problems for the rest.
I am concerned though because one of my plants (that is as tall as I am and was setting fruit nicely) is showing symptoms. The fruit is not growing and the top foliage is small and yellowish with a tinge of purple. I fertilized it along with the rest weeks ago and it seemed healthy then. I'm suspecting that some sort of virus took advantage of the weakened plants although I was careful to sanitize my tools and wash hands when working with them.
While the rest of my plants look healthy, the yeild looks like it will be small. It seems that the plants that put the effort into making fruit, were the ones that died. (Although, it may just be that the plants aren't setting fruit now because it is getting so hot.)
