Re: apples- I haven’t heard of any compatibility challenges with triploids onto diploid rootstock. Just now my mind led to considering if anyone has explored trying to come up with a semi-dwarfing or dwarfing triploid rootstock for disease resistance and vigor.
Along with the topic of persimmons and Diospyros in general as mentioned above by Clark, what I am currently trying to figure out is Asimina triloba. Mr Sam Norris (no longer with us) worked with colchicine to attempt to adjust ploidy of pawpaw seedlings with the hope of creating seedless F2 progeny after a back cross with the ‘standard’ diploid flowers.
It’s my understanding that certain pawpaws with genetics passed down from Mr Norris’s seedlings have a higher rate of graft failure. The most noteworthy amongst them being 250-30, for example.
The more I learn, the more I realize there is to learn…
A note about colchicine- it is very much a TOXIC chemical in a literal sense (not an organic grower talking about synthetic chemicals or growing things in plastic being ‘bad’ sense) and extreme caution should be exercised when considering using it. It’s my understanding that Mr Norris may have had some health complications related to his experiments which might have contributed to his passing. This has not been confirmed.
PS- Clark, I think the persimmon challenges may be more due to other factors as @Hillbillyhort and others mentioned. This could absolutely be the case for the pawpaws too. So many variables… Persimmon wilt - #4 by Hillbillyhort