Since beans like all legumes don't need or even like much in the way of nutrient supplements the odds of that being the issue are slim.

More likely, since it appears to be on the newer top growth and if you are having to water every day, that the plant is root bound in the container and shutting itself down as a result. Root bound plants can't absorb nutrients and water just runs right through the container. Plants in such small containers never have a normal life span so we accept what production we can get and then pull and/or replace them.

Dave

Interesting. I don't even like beans but I grow these because it's pretty easy and my husband and mother like them. So I guess I won't be too concerned if these are getting close to being done ;)

Yeah I agree a lot of times when beans are starting to get yellow leaves it usually means they're done and throwing in the towel. Did you keep the beans picked regularly? They also shut down if you let too many beans on too long especially in confined pots as most plants will since the plant doesn't produce beans for food but for reproduction. Once they have enough maturing beans they just say to themselves mission accomplished and die just like salmon. My dry cannanneli and Jacobs cattle shelling beans are yellowing and dying off right now

I've been harvesting every few days. I grew these in a raised bed last year and they kept on producing into fall, in fact I had to pull the plants before they were done because they were getting huge and shading other things too much. So it does sound like a container issue.

True. You can't compare in ground growth or production with container growth and production for any plant with any validity. Too many different variables. Container gardening has its own distinct set of parameters and rules.

5 gallons is a very small container in the world of container gardening. But even really big containers will always have a shorter lifespan and lower production than the same plant grown in the ground simply because it is "contained".

Dave