Diagnosis Request

[Traveler]

Attached are 2 pictures of my most productive plant, Dester, which started having some lower branches turn yellow about two weeks ago when hot weather set in. I didn't view this as unusual and simply removed them. However, the yellowing has spread to the middle part of the plant even though the top was looking great and setting new tomatoes. The yellowing tends to be on the full branch and not just one side of the branch. Also, grey spots started to show up on leaves on the lower half of the plant when a rainy period set in. Finally, I noticed this morning that new growth at the top is starting to wilt a little, perhaps from too much rain.

Thus, if this is not normal decline, I am requesting diagnosis and treatment advice.

[Cranraspberry]

@Traveler I might be seeing fusarium everywhere, but that looks an awful lot like it to me.

[MissS]

It's either fusarium wilt or verticillum wilt. The two have almost identical symptoms and both are fatal. To get a definate diagnosis you should take a sample to your extention office. Pull the plant and as much root as possible and all leaf debris. It is soil born and can last for years in your soil. When temperatures get hot both of these diseases flourish which also happens to be when you are hoping to harvest some nice fruit.

[Seven Bends]

I would say this is not normal decline, and I agree that fusarium is a strong possibility. While the yellowing does seem to be affecting both sides of the leaves, it looks like possibly one side of the plant is more heavily affected than the other (but it's hard to tell from the pictures). Anyway, the one-sidedness of fusarium isn't absolute.

Verticillium likely would have prominent notch-shaped dark lesions coming in from the margins of the leaves.

It's possible this could be due to soil saturation from heavy rains, but it seems like that might look more like overall yellowing and wilting rather than the distinct patchiness in your pictures. Here's a discussion about wilting and yellowing after heavy rains in North Carolina; see if there's anything helpful here: https://burke.ces.ncsu.edu/2019/06/wilt ... tial-rain/ You could try pulling back any mulch to help the plants dry out, and adding some fertilizer. I doubt this is your problem though, unless the ground was basically under water for awhile.

I can't see the gray spots you mentioned in your pictures. Maybe you could post a closeup of the leaves, showing the spots? Early blight could look basically like your pictures, except normally there's a lot more brownish splotching, and you'll find the brown/gray/tan "bullseye" type of lesions. And early blight doesn't cause wilting of the upper part of the plant; it moves up the plant from the bottom, yellowing and then killing the foliage, without any notable wilting until the branch basically shrivels up and dies.

Bacterial wilt wouldn't have this distinct, patchy yellowing.

It looks like your plant has multiple stems. You could try removing the most heavily-affected stem and cutting into it to look for the brown discoloration of fusarium.

[Seven Bends]

It's either fusarium wilt or verticillum wilt. The two have almost identical symptoms and both are fatal. To get a definate diagnosis you should take a sample to your extention office. Pull the plant and as much root as possible and all leaf debris. It is soil born and can last for years in your soil. When temperatures get hot both of these diseases flourish which also happens to be when you are hoping to harvest some nice fruit.

This is good advice about pulling the plant and digging everything out. I'd cut one of the stems first to look for discoloration, and if found, remove the plant immediately. The one time I had fusarium on one plant, I dug out the plant right away, along with a couple gallons of the surrounding soil, which I threw away in the trash. The problem didn't recur.

Don't compost the plant or the soil and don't put them anywhere in or near your garden. Also remove and discard the mulch and any nearby weeds. Wash your shovel and your gloves and hands before touching anything else.

[bower]

I was going to suggest fertilizer for the rainy washout, but I have zero experience of fusarium and wouldn't recognize it.
I had the Grey Spot for the first time last year and seems to have carried over in the greenhouse to this season in spite of cleanup. The spots don't seem like a big deal and could be mistaken for mechanical injuries early on, but it's definitely worth removing them, as it seems to me they will spread if you don't. I have a few thrips as well, they seem to get it started.
Hope this is the only plant affected by fusarium, if it is! Good luck...

[Shule]

…
Verticillium likely would have prominent notch-shaped dark lesions coming in from the margins of the leaves.
…

In my experience with my strain of Verticillium, it doesn't usually get the V-shaped lesions/chlorosis. It only does that once in a while (I'm guessing about 4% to 8% of the time). Usually, the lower leaves start to yellow similar to nitrogen deficiency (without spots, and they might dry out after that), but it does it in a certain way that I can recognize pretty easily by looking at it in our garden. One remarkable thing about Verticillium, though is that it can spread to a very wide variety of plant species. If it's Verticillium, your tomato possibly isn't the only thing infected. Check other plants from other species for yellowing on the lower leaves that usually wouldn't have a reason to yellow (including weeds; our weeds and most of our other plants never got chlorosis, pretty much until we got Verticillium; now it's pretty normal to see some yellowing on the lower leaves of our prickly lettuce, or some crispy lambsquarter; it makes the older horseradish leaves dry out; it even can get to houseplants, like golden pothos, but it doesn't kill them; it just makes a leaf here and there turn yellow more often). Verticillium infects all kinds of stuff, including species that are supposed to be resistant (but it doesn't kill every species it colonizes). However, it might be isolated to that plot of soil.

[Shule]

The yellow leaves often loosen pretty soon after they turn yellow. Fertilizer and regular watering, while helpful as a preventative of this symptom doesn't seem to reverse the yellowing in already yellowed leaves (while with nitrogen deficiency, it would reverse it). Verticillium symptoms can seem similar to dehydration. It doesn't seem to affect new shoots like Fusarium does for Cranraspberry, though. The new growth is usually fine and never seems to yellow.

Also, while the fertilizer helps reduce symptoms, it doesn't totally eliminate them (at least not for every plant).

Removing all affected leaves as soon as possible does seem to help (if the plant [not just individual leaves] hasn't discolored and wilted, yet). Sometimes only half of the plant or so wilts.

[Shule]

Oh, speaking of golden pothoses, I experimented by spraying rubbing alcohol on a yellowing leaf, and that actually might have reversed some of the chlorosis for a good while (but it eventually came back).

[Seven Bends]

…
Verticillium likely would have prominent notch-shaped dark lesions coming in from the margins of the leaves.
…

In my experience with my strain of Verticillium, it doesn't usually get the V-shaped lesions/chlorosis. It only does that once in a while (I'm guessing about 4% to 8% of the time). Usually, the lower leaves start to yellow similar to nitrogen deficiency (without spots, and they might dry out after that), but it does it in a certain way that I can recognize pretty easily by looking at it in our garden. One remarkable thing about Verticillium, though is that it can spread to a very wide variety of plant species. If it's Verticillium, your tomato possibly isn't the only thing infected. Check other plants from other species for yellowing on the lower leaves that usually wouldn't have a reason to yellow (including weeds; our weeds and most of our other plants never got chlorosis, pretty much until we got Verticillium; now it's pretty normal to see some yellowing on the lower leaves of our prickly lettuce, or some crispy lambsquarter; it makes the older horseradish leaves dry out; it even can get to houseplants, like golden pothos, but it doesn't kill them; it just makes a leaf here and there turn yellow more often). Verticillium infects all kinds of stuff (but it doesn't kill every species it colonizes). However, it might be isolated to that plot of soil.

The fan-shaped or v-shaped lesions extending in from the margin of the leaf are diagnostic for verticillium on tomato. It would be pretty unusual to have verticillium on tomato and not see those lesions, unless you removed the yellowing leaves before the lesions developed. I'm not saying you're wrong about what's in your garden, just that it's not the usual presentation.

Verticillium (cool) and fusarium (warm) thrive in different temperature ranges, so that's another clue about which disease it may be.

[Seven Bends]

Removing all affected leaves as soon as possible does seem to help (if the plant [not just individual leaves] hasn't discolored and wilted, yet). Sometimes only half of the plant or so wilts.

Are you saying that removing yellowing leaves from verticillium-infected plants will slow down the disease? What would be the reason for that? The disease is transmitted through the vascular tissue, from the roots upwards.

[Shule]

Removing all affected leaves as soon as possible does seem to help (if the plant [not just individual leaves] hasn't discolored and wilted, yet). Sometimes only half of the plant or so wilts.

Are you saying that removing yellowing leaves from verticillium-infected plants will slow down the disease? What would be the reason for that? The disease is transmitted through the vascular tissue, from the roots upwards.

Only if the plant hasn't wilted, but I'm pretty sure. I have no idea /why/ it seems to help, though. What it helps with specifically is stopping more leaves from yellowing and dropping off than otherwise would. I'm not sure that it relates at all to whether the plant will wilt. But yes, it's the same thing that causes the V-shaped chlorosis (which dries out afterward). It only makes a V shape in some species of plants (like tomatoes and wonderberries, and not terribly often). It makes potatoes look kind of zombified; like they're dead (but they're not dead). On the lambsquarter, it looks pretty weird. I forgot what it looks like on sunflowers; I think it's either just yellowing, or maybe it has the V-shape sometimes. I don't know. I don't think the horseradish even yellows; the oldest leaves can go directly to crispy. The prickly lettuce loses it's lower leaves and they yellow (I don't see the V-shape on them at all). It doesn't make them wilt. On strawberries, it makes the leaves chlorotic (no V-shape ever that I saw), and eventually dried (they dry out and die, but I don't know that they ever wilt). There was no V-shape on the artichoke that brought the disease (but it did have yellowing); it never wilted.

The only species I've seen wilt from it are potatoes, tomatoes, one wonderberry plant one time; and very young plants die from it (like young lambsquarter and young wonderberries die from it; I don't know that I'd say they wilt); oh, and anything growing next to infected potatoes seems to die, even if it's resistant (including the next year in that spot, sort of).

[Traveler]

Fusarium.jpg

Those that advocated for the murder of Dester on the grounds of fusarium seem persuasive. I have removed only the declining portions of the plant and split open the branches near where they met the stem before removal. Most looked normal to me, other than the yellow leaves. However two did seem to have brown streaks or spots. The lower parts of the stem, right side of the picture, are a little out of focus but the brown areas can still be seen. Are these brown areas in the split stems evidence of fusarium?

[Cranraspberry]

@Traveler it’s easier to see on a cross section cut, but I see vascular issues on both stems in your photo.

IMG_4509.jpeg

[Cranraspberry]

IMG_9983.jpeg

Here’s what I mean by cross section