Black sapote problems

[CA Hockey]

Hi all

I have 2 in ground black sapote, reinecke and ...black beauty(?). I've had them for 3 years. They flower every year, and each year the flowers dry up and fall off. They look very similar to persimmon flowers (I believe they are related). I know some plants have male flowers, but as I have grafted plants the source material should be able to bear fruit.

I'm at a loss at this point and am thinking of replacing the trees or topworking them. It would be a shame to sacrifice 2 great looking trees, but after 3 years and with no fruit to show for it, I'm hard pressed to keep these when they should have fruited within a year.

Am I missing anything? Doing something wrong?

[achetadomestica]

How tall are they?

I have 2 different seedlings growig and one of them produced a couple
fruit last year at 2 years old and this year it has 10+ fruit. The other tree has
not grown as fast and is flowering this year constantly but hasn't set yet?
I assumed the second tree would start setting eventually? The tree
that produced fruit was the only tree that flowered and set last year

[CA Hockey]

6 feet tall and 8 feet wide. Many branches, bright green leaves, almost 100 flowers per tree, maybe more. They look just like persimmon flowers  but end up drying and falling off.

[achetadomestica]

I recehecked my smaller tree and it is loaded right now with flowers and none
are setting.

[ChirimoyaNirvana]

My Black Sapote tree does the same thing.  Tons of flowers and no fruit.

[Ulfr]

Is humidity a factor in pollination? It is with some other trees.