chocolate pudd. tree

lachlann says...
The following is only guesswork.
It may be due to a lack of pollination if growing conditions are otherwise okay and the tree is old enough. I think some seedlings especially may need pollination.
You may be able to work out if the flowers have male or female parts or both - I guess you might be able to find out how to identify this on the internet for persimmon flowers which are in the same family.
If you suspect that it is a pollination problem the solution would be to plant another one - especially a named variety, or graft some of another one onto your tree.