That looks like crown gall, Agrobacterium tumefaciens.

You did the right thing getting rid of effected plants.

That's a disease I haven't seen before...would go well in a tomato horror movie. ;)

Sorry that you trashed plants that would likely have receoverd.

It's not a disease at all. Instead, they're wonderful images of root intials gone wild.

All that exuberant growth of the root initials leads me to believe that a weed killer was used somewhere in the vicinity, perhaps 2, 4-D, and or a weed-and-feed that included 2,4-D or dicamba.

Hmm. I should read posts more thoughly.

OP has more evidence in the post to verify the weed killer problem.

OP wrote "The leaves started to curl a bit over time, and the new leaves were thin and curly. "

Aha! Definite signs of 2,4-D or dicamba.

Beyond that, that new curled growth definitely *wouldn't* occur if the problem were crown gall.

jean

leaves curl for more reasons than just herbicides

also what some calling "curling" others might call "rolling" or "wilting"

It could be possible that several things are effecting the plants.

While they do looks somewhat like adventitious roots, I can't see how those would be able to grow from the inside of a split-open stem. That's what seems abnormal about it and more closely matches up with crown gall.

So, let's hear from jameebooz.

Beyond that, when one combines overgrown root initials with the curling new leaves -- admittedly, no image to back up what sort of curling -- one possible conclusion, also the most likely conclusion, is herbicide damage, typically inadvertent.

Herbicides can drift for miles. Just how far, and just where they land depends upon multiple factors, among them prevailing atmospheric conditions, the product applied, the temperature during & following application, and the method of application.

Then, too the sensitivity of the plants, and the dose received, determines the outcome.

The root initials show obvious excessive growth which was most likely incited by an herbicide which mimics auxins, a normal plant growth hormone.

Another person posted images that are nearly the same as OP's. His response to my diagnosis was basically "I forgot I had used a weed killer." When I locate that post, I'll provide the link.

Okay, when considering leaf rolling alone, many inciting factors are possible, including physiological leaf roll/curl.

My decision in OP's case, was the combo of symptoms.

Here's a link to a post with curling due to herbicide drift
http://forums2.gardenweb.com/forums/load/cornucop/msg072155401394.html?3

jamie -- is that what yours look like?

Here is a link that might be useful: curling due to herbicide drift

Here ya go -- "strange growth on stems"

http://forums.gardenweb.com/forums/load/tompests/msg0711543716136.html?2

Here is a link that might be useful: overgrown root initials = herbicide

I can show you lots of pictures of herbicide drift.

If I looked around hard enough i could also find other pictures where diseases which block the flow in the vascular system cause root formations near the sites of blockage (pith necrosis and bacterial wilt do this).

But these look like tumor like growth of cells and their presence and growth have caused the stem to split open.

Yes, they do look like tumor cells.

They are tumor growths, and they're due to an herbicide which imitates plant growth regulators.

Here's information, and images, from the University of California.
http://wric.ucdavis.edu/information/herbicideinjury/growthreg.html

Scroll down to the final image to see adventitious stem growth as in OP's tomatoes.

While I am definitely not an expert, I have a plant with the *same exact* issue. It could be a twin of Jameebooz's plant.

My is herbicide damage. Our lawn care company got overzealous with a herbicide application this spring. I lost 5 of my 13 plants. One plant was only slightly damaged by drift and recovered. That is the plant that looks identical to Jameebooz's. While it's unattractive, I have not found it to affect fruit production. The plant is a pear variety and has set over 100 tomatoes.

Kim