Been an organic market grower for a lot of years, and out of curiosity I tried planting by moon phase and kept records for three years. The rule was to plant above ground crops on as the moon was waxing(moving toward full) and root crops on the waning phase(moving towards new moon). As far as advantage in actual ripening time goes, I found out that doing that gave me ripe crops anywhere from 1-4 days earlier than before. I did notice that, since I was paying attention, that above ground crops seem to do much of their maturing during the new moon-full moon phase. Book I read puts it all down to gravity....during the period that the moon is moving towards full(and its orbit is closest to the earth) it exerts a gravitional pull on the earth, actually reducing the earth's gravity. Makes it a bit easier for above ground crops to grow. Conversely, during the full moon-new moon phase, the moon is further away, exerts less gravitional pull on the earth, making it a bit easier for root crops to grow. Makes sense, I reckon.