I would look at the bottom leaves and look for signs of nitrogen deficiency. If their one month old and your getting yellow leaves at the bottom then I would think the plant has already used up most of the nitrogen, so it should be safe going full strength. Then again, if you just bought some expensive beans I'd hate to risk it, so I'd just go half strength.
I'd go 1/4th if I had absolutely no clue as to how strong it was. I've used Alaska Fish Emulations before and it's pretty safe stuff. I have burned plants with it though, but that was my fault, I just eye balled the amount. The good news is that plants recover pretty quickly, especially in their vegetative phase.