Unidentified tomato desease -- maybe russet mites?

[apprentibidouille]

Hello,

I'm a newbie in gardening, and my tomatoes always seem to die from the same disease, which I couldn't identify.

It typically starts from the bottom of the plant and gradually affects the entire plant, until it dies.

First the leaves dry, and then the stem (as can be seen in second picture), which feels like hollow after some time.... Anyone has some idea of what I should do to stop or prevent this phenomenon in the future? I live in South California.


Thank you for your help!

Edouard

[applestar]

Not positive as this is a new pest on tomatoes for me as well, but it's possible they have russet mites. You need to look at the leaves with high power jewelrer/geologists loupe or low power (50x to 100x) microscope. They look like dust to unaided eye and microscopic rice grains magnified. And they shift and wave around like underwater polyps.

I looked at mine through my kid's handheld lighted magnifying loupe (probably 10x) aided by 5 MP iPhone camera at full magnification:



Their life cycle involves dropping to the ground and emerging from the soil so the plants are affected from ground up and isolated infestations on tender new growths. They are resistant to sprays and can be spread by air movement and on clothing.

Best defense is predatory mites.

[apprentibidouille]

Thanks for your prompt reply... It's true that the leaves are covered with some "dust", and especially on the leaves which are "under attack" as illustrated here.... I'll try to find a magnifier of some sort to confirm the diagnosis !


Thanks,
Edouard

[applestar]

UGH! Found some more of the buggers on my Winter Indoor Tomatoes
Posted pictures here
https://www.helpfulgardener.com/forum/vi ... 22#p324022

[imafan26]

If you have the same disease year after year, are you growing them in the same spot? If you can it helps to move them to a new location or if you can't, skip a year or two to decrease the pest population. I don't know if you can do this or not, but I can avoid some issues if I plant slightly out of season. If you can plant a little earlier before the pests arrive, the plants are bigger and sometimes can handle more stress than younger plants or at least you can get a harvest before the plant is a goner.

[suncitylinda]

I live in SoCal and have had tomato russet mites before. The stems in your first pix have that sickly suspicious TRM look. The second picture, I don't know. I have never really been able to actually see anything that clearly. Makes me wonder if you have spider mites, which ARE visable to the naked eye, but tiny. If you look closely you can see the minute webbing. In either case powder sulfur, available at many nurseries will do the trick. Spider mites require multiple application spaced several days apart. I think Lily Miller makes the one I use. You can mix it into a liquid spray but I have always used it as a powder and had good results. I have a powder applicator but now I just use the applicator that comes with the can. Quick and easy.

[Lindsaylew82]

Here are mine. I don't think it's russet mites, but I'm not sure. It's not presenting in the classic way based off what I'm reading. It's mainly on the main stem.

The brown leaves are blight, I'm pretty sure.

[suncitylinda]

A sign of TRM that does not require high magnifier is the stems no longer have the traditional hairs. they are either broken down or gone. Also, once the mites gain steam you will see green wilted branches as they travel up the plant, followed shortly thereafter by crunch brown.

[applestar]

Exactly. It's heartbreaking to see the TRM (Tomato Russet Mite) travel up and destroy once a beautiful tomato plant.

I'm not saying for sure this works, but I had an interesting demonstration of my Garden Patrol at work this season. Especially if you have a long growing season, it may be worth NOT SPRAYING MITICIDES and letting your plants recover after the appropriate predators (usually predatorial mites) discover the russet mite population:

In Applestar's 2014 Tomato Gardens

I thought I posted about this before, but maybe I didn't.

I had a bunch of short dwarf and micro varieties in 3 gallon square containers and a few others in smaller containers that had been waiting to be planted in 5 gallon buckets. But they started getting overwhelmed by russet mites and I was desperately putting them in wildflower beds, clover lawn, and under 2nd year flowering parsley, trying find the Garden Patrol members that could take care of them. But all of them got russeted all the way to the growing tip and it looked like they were goners. In fact some of them died.

...then I started to see fresh new side shoots and amazingly these were free of any sign of russet mite infestation and damage. No russetting, no slowly dying leaflets.
<<<lots of pictures etc. follows>>>

Here is one of the photo collages in that post/thread -- you can see the destroyed main stem and the new unaffected fruiting shoot:

[rainbowgardener]

Lindsay - have you checked for the signs as above? I'm not convinced that yours is russet mites. It seems to have more that spotted leaf, septoria look.

[Lindsaylew82]

Well, they definitely have septoria. They all have septoria. They all have blight. 6 straight days of rain....

But this one is bronze on the main stem only. No other signs.

[applestar]

I found a picture of the magnifier I used above in combination with the iPhone:

It's from Brookstone's and is a 10X ...and pink.