Oh my goodness, you are right! That is what mine looks like!! Still could be root root, as the symptoms are very similar. No sign, that I can see, of a stem borer. I have not yet pulled up the plant. It has some green tomatoes and I was going to see what happens. I drenched the soil with water with cornmeal and cider vinegar, in an attempt to attack the fungus. For a day or so, the plant seemed to rally, but now it's taken a turn for the worse, again. I am starting to agree, though, with the person who started that thread: it's quite possible that, in this part of the country, tomatoes should be more of a fall crop. We have had SO much rain,lately, as well as June temps in the 90s. A sure recipe for disease
