I would say that unless you are an accomplished grower and sure that you have every other aspect of your grow dialed in, stay clear of folar feeding, just too many potential problems for your potential returns.
First a few questions... Indoor or outdoor? Soil or hydro? Outdoor in soil, go for it. I recommend only ferts designed for foliage, and only in the early mornings or just before sunrise to eliminate potential burn. More is not better I suggest going even weaker than suggested. Also beware of bonding agents as the may clog the stomata, how the plant respirates.
Indoor with hid's, and hydroponic grows. I suggest skipping folar feeding as potential problems far outweigh any potential benefits. The fact that ff recks mylar, will cause bulbs to explode, will dirty vented hoods , decrease all reflective material, potentially clog stomata reducing co2 and general respiration, and increase the likelihood of mold or mildew problems.
As for hydroponic systems... If you are doing everything correctly your plant already has everything it needs all the time, so why ff?
PEACE