the surface appears to be eaten.

i'm having the same problem, also greenhouse beans. I think that it is sunscald. Curious to know whether you got a crop yet last year, as I see you posted this last year.

Possibly Environmental Leaf Scorch most common when the weather is hot, dry, and windy and a plants roots cannot supply enough water to the leaves to replace that moisture lost to transpiration.

http://www.mortonarb.org/trees-plants/tree-and-plant-advice/horticulture-care/leaf-scorch

What conditions are present in that greenhouse?

kimmq is kimmsr

Hello again kbjug and kimmq, You know, that was well over a year ago, and I cannot remember, for sure, which beans those were, but I did get a great crop of pole beans last year, and I am thinking that this was a problem with the pole beans when they were young. My young beans this year had some sort of wilt in places on the plant, but I ignored it, and now they are doing great. I think that sunscald or Leaf Scorch could be the problem. We live in NM and it is hot and dry here often. I do water weekly, in the spring when this occurred, but the sun could have been very hot. In any event, I don't seem to have that problem anymore, whatever it was, without changing my practices at all, and just letting the plants do the best that they could. Peggy