It's to be an effect of high potassium in molasses... it's commonly used (as well as sugar) and some people love it, other don't give a penny about it...
In my case, I do not see the real rational of adding sugar to teh plants (they produce their own!), but with molasses... well, the high potassium (and other micro-nutrient in it) can indeed help... the question is, if it's really necessary, as most people also add complete fertilzer as well to the mix...