I get huge fruits, very juicy, and sweet when around Feb/March I feed the dark color grumichama with a thick layer of cow manure aound the drip line and I bit beyond it. I keep the soil nice and moist by watering the tree two (2) to three (3) times a week. Grumichama loves water!
I believe that any nice manure will do the job, cow, goat, horse, even elephant manure will do it!