In the ground or in a container? How big/old? Fruit set? Signs of pests? How much feeding? With what? Chance of root burn?

Usually what you describe is a result of root damage but what is causing the root damage depends on lots more info.

I watered her, I checked the soil for moisture, I let her dry out some,

Could still easily be over-watering and shallow rooting. Not enough info provided to know. So details - how watering, how often, how checked, how deep is soil moisture, any signs of roots on the surface, etc?

Maybe it is too hot and humid here to grow that variety?

Many do with no more problems with it than with any other variety so it isn't the variety, it is something that is being done or not done to the plant..

Dave

It's in the ground at the base of a hugel. We use Black Kow for fertilizer. Lost a small tomato right next to it a few weeks ago. Watered when needed. Lot of rain recently. Other tomatoes seem happy. No root nematodes or anything on the tiny tomato I yanked out. No foot traffic on it. Feritilized twice with just a tiny amount of Tomato tone about 1 1/2 months apart. About 7-7 1/2 feet tall. Gets all day sun. I thought it was dried out one time, so I watered it well and it came back for about a week. I'm thinking of topping it to about 4 feet and see if it will revive. I hate to lose it. She gave us about 75 fruits so far and is loaded with about that many more and is full of blooms.

What is a hugel and what are the effects it could be having on the plant?

Dave

A hugel is a German term for a mound. You start with tree logs and branches. Mix in kitchen scraps, compost, grass clippings, manure, and anything natural. It is a Permaculture thing. After one year you shouldn't need to water or fertilize. This is our first year and the plants are growing like Bonkers. I don't know why it is being bothered. Everything is organic except the Black Kow. The other plants are growing so fast I can almost watch them grow!

Can't help you then with the effects of this hugel thing but given the proximity of the plant to it I would suspect some sort of detrimental effects on the plant. Especially if plants NOT adjacent to it aren't having problems.

Dave

OK. Hers is my 02 contribution.
You fertilize and on top of that add Black Kow manure. I know BK manure is pretty strong. So what happens, when the nitrogen is mixed with the composting material inside the hugel, it works as an activator to compost faster and maybe (maybe) generates excess heat that reaches the plans roots. So then wilting can be due to the soil richness and temperature. On top of that you are in zone 8B in GA !!!

My first thought was do you have moles? Sometimes they will tunnel right under the center of a big plant in my garden and bring it to its knees, especially in hot weather. Add that to the fact that when it is hot they are active further down in the soil so their tunnels can't be spotted easily and you can have a real head scratcher.

An errant mole took out one of my black cherry transplants early on this year, but that plant was a trooper, already sending out new roots the second day and it has recovered to be a robust vine a bit behind its peers but healthy.

Could you have accidentally included some black walnut wood in your Hugel? Could your tomato plant have got it's roots into an airspace or dry spot in your bed?