The only serious bean problem I have dealt with in 15 years is MBB, so not a help.

They look starved.

What size container are they in?

What kind of potting mix?

What kind of fertilizer used? How much & how often.

Are these beans container grown? If so, I think it is a container growing issue. I don't have experience with that.

Jim

Oh, they are definitely eager to be planted :). I will plant them out tomorrow. I had to grow them kind of huge first, so they can withstand the hordes of snails we have around here.

But this business with the white leaves gets much WORSE after planting out. It's not from crowding. It gets worse as they get older.

Is it a nutrient thing?

I hate to ask such a basic thing, but have you checked under the leaves for spider mites? Whenever I get leaves turning white on beans it is always a little visitation of spidermites. It's the only problem I seem to have with them, well, and stink bugs in very recent years.

@Sunnibel:

I did not look, and when I read you post I thought, 'Boy am I going to feel foolish if that's what it is.' :)

But I have now inspected them closely, thwacked the leaves over dark fabric, etc., and I see no sign of spider mites or spider-mite-related program activity.

The leaves are dead at the white spots, if it's not clear in the photos. (I am adding details when it occurs to me they might be useful.)

Really? No-one knows what this is?

It happens to my beans every year, and kills about 2/3 of the young plants before they produce anything, or much. The most resistant plants still get it, but it takes till later in the summer to kill them.

I feel like it has to be some common, obvious thing, but like I said -- lots of photos of bean diseases on the net and none seem to look like this. And my local garden friends don't know either.

I do grow the beans in different spots... does not seem to help. So far my only solution is to plant a lot more than I need and not rely on them....

Have you investigated Downy Mildew of beans?

Thank you rhizo :).

I don't think it's downy mildew. The white spots are just dead patches, that spread. They are translucent. There is not a surface growth of white stuff. Does this make sense?

I think it is insects rather than disease. Leafminers that don't leave tunnels or Cucumber beetles which love beans.

Oh, that's an interesting idea, little_minnie!

I didn't know those guys liked beans! I do get leafminers of a nontrailing sort on chard and beets, tho none yet this spring. And I it's very early for cuke beetles here.

The bean have been out of the greenhouse...um... two weeks max. Do you think that's long enough for miners to do the damage? The spots on the chard and beans are more of a gray-brown color, but maybe different miners or different leaves changes that?

The white on the leaves in the first picture looks like the results of water droplets on the leaves + sunshine which has "cooked" the leaves and killed them. There appear to be a few other things going on with the leaves in the first picture also. The pilly bulbous areas on the center leaf and varying shades of green could indicate a seed borne virus. Next to that, the leaf appears to have had a bite taken out of it, but there is also some yellowing right at the edge. This is most likely insect damage, but could also be blight starting.

The second picture looks like the beans have been in saturated soil too long and the roots are dying. The way the leaves are somewhat vertical is a sign of drought stress, but in the absence of dry soil, this is a sign that the roots have a problem and aren't taking up water and nutrients, hence the drouthy reaction and general appearance of poor nutrition. Beans don't like saturated soil and just a few hours of saturation can pretty much kill them or set off the root diseases that will destroy the roots.

I would use new seed next time you plant to eliminate any seed borne diseases you may have, and make sure they are in a light soil that doesn't stay saturated or sitting in trays of water, plus water the soil and don't spray the leaves. Beans are fast growers and you won't lose much time by direct planting in the garden rather than in pots and transplanting.

It's not water droplets....

Here is a link that might be useful: The enduring myth

You have a good eye, beeone! And thank you :).

The bites are from slugs/snails, which are also the reason direct sowing is impossible here. Bean sprouts are too delicious!

And yes, the one tray had sat overnight in water and was sad. Sunny day, with need for steady supply of water, turned to unexpected rainy night, and this photo was taken the next morning.

I will watch for blight, which I have not had before, and thanks for the virus info! I have been saving seed of the most slug and snail resistant plants for a few years, which has helped a lot in getting any crop at all, but now I understand from what you said that there may be this drawback.

My beans often get sunscald early on but it doesn't kill them. Nila mentioned hers die of this by the end of the season. A lot of my plants get leafminer (but not tunnels so much) and cucumber beetle damage. Again they do not die from this. So disease maybe is the problem not insects.

The first year I had leafminers that didn't tunnel in my veggies they got to my cauliflower mostly. I thought it had a disease but it wasn't.

Hmmm, that is a good point. Leafminers in my chard and beets don't kill them.

It does NOT take all season for this stuff to kill the beans. It kills many of the plants withing a month or so, IIRC. Only the strongest 10% live all season with it.

I picked these two leaves off one plant (one of the runner beans from the top pic) for close-ups. It does kinda look like leaf miner damage to me.. what do y'all think?

One thing that's weird: These leaves looked mostly dark green and healthy IRL. But the camera shows much larger white patches and yellowish patches that are invisible to the eye.

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I get the same thing on my pole beans and have been trying to figure it out also. I am using different seeds this year and growing more bush beans as they seem tougher. My opinion is possibly Anthracnose which I believe stays in the soil so the anti-fungal is not much help. Could also be mildew, but it does not respond to treatment. Good luck, I am hoping this year is better.

Thanks, wisbill, I wish you luck, too! It's good to know I am not alone with this mystery.

Still could be leaf-miners. The leaves look thinner in those patches as if the life was sucked out.

@little_minnie:

Yes, I agree.

I ordered some fabric, and will search and destroy for leaves with patches and eggs. Eggs would confirm the diagnosis.

I am going to tend to agree with beeone, and say this right off does not scream 'disease' to me, nor does it look like insect damage. Looks more like sunscald (water droplets essentially boiling on leaves from overheadwatering/full baking sun afterwards). The pale leaves around it just seem nutrient deficient, probably rootbound and ready to be planted.

Hokie! You sure didn't learn that myth at Va.Tech. Water droplets just don't (can't) boil on plant foliage. It's a matter of physics. Water droplets are flat....not the rounded lens shape. The exception would be for those plants with hairy foliage where droplets might be suspended above the surface....creating the magnifying glass shape required for burning.

Damage could be caused by salts or sediments in the water.

Rather than our feeble attempts at guessing what the problem might be
It might be a good idea to contact your local extension for some guidance. They will (hopefully) suggest sending in plant and soil samples to the pathology lab.

Since you have no idea if this is caused by biotic or abiotic factors, it seems like you ought to call on the 'big guns '.

Another possibility is that you have more than one thing happening over the course of the season that look supperficialy similar, like early exposure damage then later mites (not that I'm saying you have to have mites, just an example)? But I've been thinking like rhizo, if it is so mysterious perhaps it is time to ask someone with a lab to take a shot at IDing the problem?

The second picture looks to me a spite mite issue. it's hard to see the mite sometimes since they are so small and they might just be off the leaves you happened to be checking. Did u try water the leaves often (earlies in the day so it will dry out by the sun)?

By the way, the first pic looks to me the plant is ready for bigger space. I had this prob w my indoor seedlings several years. It's better to plant them out before this happens. Once it's planted out, it has a better chance to recover (just be prepared that some may not come back).

Thanks guys, I didn't realise a lab was an option. We have a local 'master gardener' program, but they don't know very much, IME. They are just people who have taken a class.

And sunnibel, you are right that it could be multiple things. I will see what progresses and bring samples to the extension service this summer :).

I like how everyone loves to catch everyone else in 'gotcha' moments on here, pretty typical. Extension agents won't know, Master Gardeners certainly wont know, and rhizo isnt helping a whole lot either just telling you who is wrong or right, I just put in my two cents, not a disease or insect. Honestly in the world of plant pathology, there could be thousands of explanations. Even a phD may have trouble telling you a straight answer. Its tough. I say if it just looks superficial, plant em and see what they do, theres plenty of photosynthetic (ooh big word, dont get mad everyone) leaf surface left.

I don't know what hokie is on about, here, what is sarcasm and what is meant seriously. Translation?

He had his feelings hurt and he's mad at me :-( Sorry, but the breadcasting of sad 'ol husband's tales is a bit of a pet peeve for me.

Nita, a visit (or call) to your local extension office will help you find out how to take samples and get them sent to the state lab. Some state universities have had to severely cut back on their services but hopefully you can get some help. Lab tests can be just as important in eliminating possibilities as in clinical diagnosis.

The problem with something like this is that it could be a combination of things as has been suggested. You'd be fascinated by the interrelationships between nutrition, environment, pathogen, and other pests.

You've stated that this occurs every year. Have you observed problems with any other garden plants? Do you live in an area where nematodes are a known problem? In which state do you live?

I guess you can see that we all love a mystery!