Dennis, I’ve had the same problem with plants of persimmon bought from nurseries.
Look at the leaves of this Rojo Brillante .
I have asked my friend Cristina, she is an agronomic engineer specialized in persimmons from the IVIA (Valencian Institute of Agrarian Research), I showed her your photo, and she confirms that it is a physiopathy due to two possible causes:
- Excess or deficit of irrigation
- Boron and Calcium deficiency
Applying amino acids and a microelement corrector, your persimmon should improve immediately.
On the other hand, a persimmon is not a suitable tree for growing in a pot, and you must transplant it to the soil of the orchard.
Regards
Jose