What you are doing by adding molasses is adding sugars or carbohydrates if you want to use the agronomic term.... however, molasses overall, is not really that sweet. That is why you have the sweetened molasses! I would strongly suggest instead of molasses to add Karo syrup or even stir sugar into hot water instead.

The yellowing is most likely due to the excess of potassium that is in the molasses. It is loaded with potassium. If you don't have your magnesium and calcium correct, it is easy to go to far with potassium (in this case molasses).

It is natural to have the leaves turn and discolor, but try to watch and see why.... is there interveinal yellowing on the old leaves (magnesium deficiency)....