Opinions wanted... Pic supplied... Solid yellow??

Nitrogen Def??
Its only the bottom and this is just the worse of them all, a few plants have this. Do i leave them alone? Pull them off? How do i fix?

I'd just give them a little tug, if they don't come off easy let em go.I wouldn't worry too much as long as your new growth is good.

Classic N deficiency and an easy fix. Feed something high in nitrogen and low in phosphate. All the other leaves look a bit pale too and would green up instantly with more N.