My rhubarb stems are splitting right below the leaves. Sometimes they ooze rhubarb flavored sap (yummy!), but not always. If it matters, due to our current round of drought I've been watering a lot more than usual.

And there are a lot of ants feeding in the splits. I can't decide if the ants are causing the problem or just taking advantage of the situation. Any information or advice would be greatly appreciated.

Henderman, is that a regular (solid) leaf stem, or a hollow flower stalk?

I doubt that ants are causing the problem - but I could certainly be wrong about that, I've never seen anything like that sort of damage on my rhubarb; I'll be interested to hear what others might say about it.

Its a regular leaf stalk. The trouble seems to start right below the leaf. I'm thinking its getting too much water but I don't really know.

Your photo made me think of squash vine borers; I did a little googling and learned that there is a "rhubarb curculio beetle" and a "potato stem borer", both of which do damage to rhubarb stalks. You might want to read the info at this site (or others) to see if it seems to match what's happening with your plants: https://www.rhubarb-central.co...

Thanks @Weedwhacker that was an informative link.
When the cracks first appeared I thought of squash vine borers as well. But I cut open a few stalks and didn't find any worms like you do with the SVBs. And I haven't seen any strange bugs.

The good news is that it seems to be getting better. The new growth is good and the old damaged stuff is withering away.

That IS good news!

Overwatering would have cause physiological damage, rather than physical damage. I too, thought of some kind of borer. I've never seen ants ever cause direct damage to a plant (except leaf cutting ants). Yes, they can produce ant hills and smother plants, or farm aphids, but not kill directly.

Update: The rhubarb got better after the damaged stalks died off. In fact with all the rain we had this year it did really well. So good that I took it to the Taos County Fair where it won a blue ribbon. I still don't know what happened to it, but I love a happy ending!

Good work Henderman!

That is truly a "happy ending" ! (well, not technically an ending, since the rhubarb will be back next year! )

Congratulations!!

Thanks for updating!

@Leftwood: You're welcome
I wish we got more updates, I often wonder how things turn out and if my advice was useful