The phantom plant killer!!!

[Smiles Jr.]

6:00 AM 6-30-2011: My pole beans were doing great. About 5 ft. up the poles, thick and luscious. A few blooms here and there.

6:00 PM 6-30-2011: Three of the 18 pole bean plants are totally shriveled and dead.

I thoroughly inspected the entire vine and especially around the soil area. Nothing unusual there. There was very minor bug damage to the leaves. The only thing I did different this year is that I put some straw mulch around the area to keep the weeds down and to keep some of the moisture in the soil. The chickens have been getting into the garden this year but they have been pecking at the worms (or bugs ) in the soil mostly.

Anyone have ideas on what it could be? Any suggestions to keep it from happening to the other plants?

 

[lesa]

Gee, that is odd- with such mature plants...Can you tell if the damage occurred at the soil level? Is the bottom of the stem dark and shriveled? I have to say, if the only thing different is the straw- I would get it out of there. Maybe too much moisture is causing the stems or roots to rot? My pole beans are always so full at the bottom, that I don't do any mulching. Sorry that happened. For every joy in the garden, there seems to be equal pain. Good luck!

 

[digitS']

When I have plants that die suddenly, I always suspect something in the soil. If I can't see the problem easily, I assume, it must be below ground.

How are your tomatoes, Smiles? You may have had good reason to suspect this problem.

So, here is a guess: Fusarium Root Rot

Flooding and wet soils are listed among precursors. The article talks about the plant's ability to partially recover.

Steve

 

[Ridgerunner]

Something that quick to that many is a little strange to me. I mulch beans and have not had that problem.

I also suspect something below ground if the plant has not been broken off above ground. Have you gently dug around the base of the dead plants to look at the stem just below ground level? I would not expect cutworms with 3 out of 18 at one time, especially with them that age. I'd be more looking for a dried, blackened. or shrivelled stem. I'd also be concerned it is a disease. Try not to touch any of the others after you have handled these.

I have had them wilt down from being too dry, but not totally die like that. A little water would revive them. In your case, I'd suspect a disease or something mechanical.

A quick thought. Did a mole tunnel under them? I've had that happen before.

 

[vfem]

Stick your finger down in the soil around and see if you notice and holes, or tunnels that just crumble when you do that. My guess is an underground preditor like a mole or gopher who destoried the roots over night.... very fast those suckers are. We have a similar issue here. One minute a plant is fine, the next a vole got it's roots and the thriving green plant is dead within hours!

 

[Smiles Jr.]

I had a very busy day today but I did manage to get out to my bean plants. I removed much of the straw mulch and closely inspected each stalk and carefully probed around each stalk and this is what I found.

The soil was damp under the straw. The soil is soft and not compacted at all. The stalks of the dead plants all look the same (see pics). Several stocks of healthy looking plants are showing signs of weakness. It appears that there is something burrowing in the soil with 1" diameter holes (see pics).

Pic #1 Stalk of dead plant. Dry, brown cracking at the soil line.

Pic #2 Close-up of one of the dead stalks.

Pic #3 Holes in soil after straw removal. I dug into these holes after I took this picture but did not see anything in the tunnel. These holes were located about 18" from the stalk in pic #1.

Pic #4 Healthy plant. About 12" from the holes in the soil.

Pic #5 This was a crawdad "castle" a few days ago. Our crawdads dig into the soil and form tall stack-like piles of soil that look like volcanoes from 4" to 12" tall. We have them everywhere here in Indiana. Sometimes our yards look like mortar shells have gone off all over the place. You can see the actual hole near the bottom of the pic. After a while these castles melt down to look like the one in this pic.

I have never heard of the crawdads doing any plant damage. But we also have moles around here. I think the little holes in the soil near the bean plants look to be too small for moles and the soil was not mounded up like mole tunnels. Something that I did not do was to pull out the dead plants to inspect the roots. Hmmmm I'll have to get back out there this evening.

What the heck do you think is going on?

 

[lesa]

Yep, moles or voles.... Not much you can do about them- unless you have a cat, that is a hunter. I had some burrow under a patch of black eyed susan's and kill them. I thought the end was near- nothing kills black eyed susan!!

 

[Smiles Jr.]

I went back out the the dead bean plants and dug around in the soil some more. I found that the 1" diameter tunnels DO lead right to one of the dead plants. I also dug up the roots to several plants and all look pretty much the same. I'm surprised that there are so few roots on these vines. I guess I expected more of a root ball for such long vines.

Pic #6 Pole bean roots.

Pic #7 Close-up of suspected stem damage.

In the close-up you can definitely see a chunk taken out of the stalk. Mole? Cutworm? Squirrel? Chipmunk? This is kind of like forensic science. CSI agent Smiles here.

 

[lesa]

The vine is way too big to be eaten like that, from a cutworm. So, you can take that off your list, agent.... Those nibbles look like mice or voles to me...

 

[Smiles Jr.]

Yep, moles or voles.... Not much you can do about them- unless you have a cat, that is a hunter. I had some burrow under a patch of black eyed susan's and kill them. I thought the end was near- nothing kills black eyed susan!!

Hmmmm. About two weeks ago I saw one of our chickens running around with a vole in her mouth. I thought it was a mouse until I looked closer. Where are the snakes when you need them!!!