I prune once a year and use bioflora for Fert. I will post pics of my yard soon. do not let any branch grow longer than 12 inches, and make sure your cherimoya tree has low multiple branches no higher than 18-24 inches, this ensures you can keep dwarf height easy to pollinate. I keep my main canopy under 6 feet when I prune, at end of season it gets back to 9 to 10 feet, but majority of flowers and fruits are on lower 6 feet.