Sorry.That plant seems to be a goner. Try to protect the other ones.

It looks like some case of Gray Mold ? Maybe ?Maybe blight ?

How your weather has been ? cool, damp, rainy ? cloudy ?

I have similar situation with a few showing brown stems. I keep spraying with fungicide and Clorox solution. ( 7 oz regular strength per gallon of water) .

Sey

Lol looks like late blight?, It's probably from the wind or the rain, green house tomatos rarely get late blight i think?.

It does look quite a bit like late blight, but if you say only growing tips were affected than it's very unlikely to be that. There should be also some leaves affected, possibly also some fruits (tips get affected after the disease is installed, it's not usually the first sign). Don't know what it is though.

I don't "think" it is LB....It really is just the top of the plant...all the bottom seems to still be healthy and green. It is fairly isolated since I moved my PB that seemed to have fert. burn. Reading more, grey mold fits better...not perfectly, but better. I have already chopped off anything that looked like it had brown or fuzzies on it, but maybe I will try to give it, and my others, a shot of copper and give it one more week. There are some tomatoes on the lower branches I would love to have ripen if I can. May be all I get off of this one since I don't know if suckers or side shoots will reestablish themselves.

Although the skies opened up this morning so it may be a moot point. Some raw wounds where I clipped the stems, and who knows if the rest is actually infected, I may go out tomorrow and find it covered in gray... Been having such weird weather here in Portland, OR. 80s to 90s for a few days, then it pours for 2 days (but is still warm), and then it cools off into the 70's and then repeats.

Thanks everyone for your suggestions!

Temperature in the 70s (F) sounds lovely for tomatoes.

It is best to remove and get rid of any tomato plant that is wilting for reasons other than water stress. You can't save them. And they only spread the problem.

Well went out to check this morning and no reappearance so far of any icky looking "stuff" and all the remaining leaves are green.

I watered, and I am leaving for 4 days, my neighbor will water on Tuesday for me, and then when I am back on Thursday I will see if it needs to be pulled. Wish me luck.

I was skeptical of Fusarium when you mentioned having plant in a smart pot. Fusarium is usually a soil transferred disease and not typically characteristic of potted plants. Other choices are Anthracnose, Phythopthera, Timber Rot or chemical burn. I'm actually leaning toward Phythopthera.

The plant is a loss so you probably should pull and examine the roots. That would help in the diagnosis.