The fieldmen at the local cooperative here have been pushing foliar feeding of beans for several years.  This year especially since it was wet, wet, wet early in the season.  There were lots of yellow beans standing low areas that they said would benefit the foliar feeding with magnesium. 

I sprayed some low areas with their brew and the beans did green up, but I forgot to leave test strips and have no way to tell if it was the mag. or the, then abundant, sunshine that greened them up.