Q.My Morena Sapodilla trees are 7yrs old that flower heavily but have not bear any fruit. I live in Alhambra, California, any solut
ions & recommendation are apppiciation. I heard some of Sapodilla trees need hand croossed pollination, so what ia the effective way to do that? I ‘ve been tried to collect pollens from an opened flower & brush into the head of the stigma of other flower ( do this flower need to open too, there are alot of flowers open with different stage : min. opened, med or wide open) so which flower to get the pollen ? and when is the good time of the day to do pollination ? if I need help of the ants/ lady bugs so how can I keep them stay on the tree & go into the flowers to do the Job? thanks,

This sounds like a pollination issue. The female stage is first and it is just a little "nib" sticking out before it opens into the male stage. So hand pollinating is the thing to do. Use a small paintbrush, time of day does not matter.
https://www.gardeningknowhow.com/edible/fruits/sapodilla-trees/growing-sapodilla-fruit.htm
https://www.gardeningknowhow.com/edible/fruits/sapodilla-trees/sapodilla-fruit-dropping.htm