Pollination in cheeko/sapota tree | Fruit Trees | Commercial Hydroponics farming

lemme add a few observations of mine. look at the flower bunch and you will see a lot of drooping or downward facing flowers and one or two flowers that stands up right. my experience have taught me that only the upright ones turn to fruits. and it is always better that an younger sappling takes its time bearing fruits. let it dedicate its energy first into growing up to be a proper tree, and then there is a lot of years left to bear fruits. i was adviced to manually remove all the flowers for the first three years from my bud plant, and now it is bearing enough fruits for all the squirrels that visits my garden. so the point here is it might not be the absensce of insects that would be the real problem. and as ashish said, nature knows how to take care of itself, be patient and give it some time.