Maybe i've been fortunate but I can't remember when was the last time i
dealt with a white powdery pathogen, if ever. So i will let those with
experience chime in with more detail, but many of these pathogens are very contagious.

If it were myself, i would
likely pull and bag it since a lot of the plant seems affected. The
fruit do seem seem fine though, you could try ripening them indoors. But
in the meantime, as you are contemplating, get it far away from your other plants, fast.

Sorry about your plant btw :(, i hope the rest of them turn out fine.

Good luck.

Steve

Edit: almost forgot, it may be time to begin spraying your other plants. I would go with an off the shelf product though, organic or otherwise (organic includes copper, copper-sulfate and Serenade). You get the best bang for your buck by purchasing the concentrated versions.

I need the cavalry's help! I'm unclear about what it might be. Foliage pics are overexposed to see much.

That
leaf is too random of a sample to be confident about much, it could be
so many things. The stem, now that's a scary one. But the action is
described below ground.

In your summary: Wilt, that watering
doesn't cure, and pale leaves, so we know there is some sort of
transport damage starting in the roots. Some sort of "root rot" or
pest, or as you cover physical damage in the small container. We need a
closeup of the stem section from the mix level up, since the one you
have a little higher is is oddly speckled instead of especially
streaked, but might be V; LB has white spores, but the residue looks
more like a fungicide or possibly mildew in addition to something else
(though you think not mildew). Anyway the stem emphasizes a root rot
cause. Also, any adventitious or surfacing roots around that area where
stem meets mix could hold clues and if they are photogenic, or can be
sectioned for inspection, though that could hurry the demise of the
plant.

I noticed the pink plastic around the roots and in a humid
environment that is promoting fungal growth, or is it to quarantine the
infected plant? Were there saucers or did water puddle in the bottom
of this mix? Foliage problem traveling from old leaves on bottom
upwards? Symmetrically attacked or just one side, the usual questions?
Sometimes the plant doesn't show symptoms until warmer weather sets in
and everything grows faster+ plants demand more to support faster
growth.

Before you can say whether a plant really needs to be pulled you need that diagnosis (as you already know) If we dawdle too long the plant may be severely wilted before you know it. Removing leaves isn't always helpful if it is root rot since they are downstream of the "root-cause".

PC

Thanks, what both of you say makes sense. Because of the powdery nature it's obvious it's rather contagious (I have, of course, washed thoroughly and disposed of all plant litter blah blah..)

I checked just now and the wilted tops are gone. I guess it did actually get overwatered for a couple days there. So, I guess the wilting is from waterlogging and that's just coincidental to the disease.

PC, in answer to your questions: the red plastic is actually a Wall of Water (actually, this brand is called Kozy Kote). I can't really remove it now without cutting it away and ruining it (although I suppose I should probably dispose of it anyway...). It is wide open at the top and we've had an incredibly dry June, and all the other plants are okay like that. So I don't think it's a humidity thing so much as other sources of plant stress that just made it vulnerable. No saucers - all these pots are set on earth, which acts as a giant wick and eliminates the perched water table.

Yes, it started on lower leaves and traveled up and seems reasonably symmetrical. The last thing in that paragraph you wrote - that the plant seems ok until growth really kicks in - that seems to describe what happened.

I might just pull it this weekend and try to ripen those tomatoes on the counter. It's not worth it to infect other plants.

Thanks !!!!

Jenn

I am of the opinion that the problem is in the root. Have never seen mildew on tomatoes. Mold, yes, but not in this dry season. And with our bone dry conditions so far water logging seems to be remote, considering that you are an experienced gardener.

I am suspicious of that WOW , still hanging in there. With 95F++ days, it could cook the lower part of the plant and its roots , depending on sun exposure.

I also think that the stem is not healthy. Again, IMO, the root cause lies in in the roots.

Sey

Thanks, Sey. Perhaps it is mold, but yes, on the stem it looks more like mildew, but not like the powdery mildew I got on cucumbers last year. This is black spots rather than white. Maybe it's just "regular" mildew, the kind that might grow on anything wet?

I think you are right that the plant did not like the extra heat around its roots. Being a Russian variety, I think it was just cooking in the hot sun.

I just took another look at the plant in daylight. Tops seem ok now, just the lower part of the plant seems sick. I don't see anything unusual at the soil line and I couldn't really take a good pic so I won't bother posting.

The fruits still seem fine; they are a little light but I bet I could get most of them to ripen. I think they are close to full size, at least some of them. There are only 8 fruits.

I have plenty of tomatoes otherwise :)

Here is this morning's harvest!