it definently looks like early blight, and maybe some other fungus. also looks like nutrient deficiency, maybe, on some of the leaves. save your money and buy and apply only ortho garden disease control.the other chemicals you listed dont work to well. neem oil has worked for me to a certain extent, mainly certain insects.

Thanks jds912. I'm trying to stay away from any dangerous chemicals but I'm pulling my hair out trying to keep these things alive. I have been reading some about milk and/or baking soda solutions that I may try. Has anyone had good luck with those for early blight? Unfortunately it is getting late into the season here in South Florida so I don't want to risk starting any new plants to replace these that are dying. I appreciate your help!!

i have been having fungus problems this year as well. and early. usually dont show up until early july. it has been hot and humid here in s.e. ga. very early. research daconil. its not very heavy, and its not systemic. just was your fruit well. much less potent than what is on the store bought stuff. once you see signs of disease, i have found it impossible to stop it. i removed infected foliage when its dry, very carefully. then i spray ortho. definently slows it down. i have something on big beef plant that i have never seen. definently fungal, because daconil and leaf removal is slowing it down. grown big beef for three years and always the first to get disese. produces loads of fruit, maybe thats why.