You should have been on a schedule of preventative spraying with anti-fungals like Daconil or neem oil. Remove the affected foliage and spray everything else. If you have caught it early enough, you won't lose the plant.

Ted

Thanks Ted,

I removed bad foliage ten days ago and sprayed Daconil. There were a few worrisome plants, both early blight and fusarium suspected. The blight issue seems to be solved and regular Daconil treatments are planned.

One plant is not going to make it. Period. Fusarium is advancing fast, 2/3rds of the way through the plant, Daconil didn't touch it. Three others have the yellowing leaves down low that could be more Fusarium or overwatering.

I was wondering if it is prudent to pull the plant or let it ripen the fruit while dying.

It was said "Fusarium is advancing fast, 2/3rds of the way through the plant, Daconil didn't touch it. "

And they won't. That's because if it's Fusarium, the fungus is in the soil not on the leaves or stems.

Just curious: how did they confirm Fusarim? What was it based on?
Did you cut the stem about 6" from the base and observe a brown inner ring (the cambriam is a thin concentric sheath inside stem,it is the circulatory system of a plant, green in healthy plants, brown in Fusarim or Verticillum wilt infected plants.) Or did they do some type of biological lab test, or what?

About what to do: it's kind of up to you at this point. It's not contageous just sitting there. (if you use a tool to cut the stems when you pick the tomatoes, don't use it on another plant without disinfecting it.) It usually is associated with watering problems, poor drainage in compacted soils, etc. Take extra special precautions to avoid overwatering the remaining plants you wish to save, meaning let the soil go bone dry down 2-3"..Below that, it should be moist, not wet. Trust me, they can take it.
Your soil will not be safe for planting any Fusarium sensitive plants such as carnations pretty much indefinitely. For now on, plant something not subject to the wilt there, and always treat the soil like it is contaminated - don't spread it around your yard, and disinfect any tools , shovels, etc that come into contact with it. Or dig it out and replace it.
When you get rid of the plant, toss it in the trash pick-up, not in your yard or compost.

Thanks Jeannie. That's what I needed to hear. I suspected most of that was the case, and I am glad it isn't contagious. This plant does sit a little lower in the bed than the other five, so it pooled a little water when I forgot to turn it off. Timers. I need these maters on timers. It's a cherry so I will leave it in until I get a couple big trusses harvested. They should be ready for indoor finishing this weekend.

As far as confirming fusarium, I did a LOT of reading, and did the stem test myself. It was text book browning of the vascular tissue. I understand it could be verticillium, but two farmers market growers said verticillium would be very odd where I am and fusarium is common. I don't have a lab test.

I did ask if I should dig out this garden, which connects to two others and is feet from a fourth which only has a few pavers leading to a fifth, and they said not to dig it up because it was everywhere around here, I would probably spread it and it would probably come back if I didn't.