KSD on lotus understock?
I have a lotus tree that's about 10 years old that was topworked about 5 years ago with various kaki - Okame, Korean and Wase Fuyu as well as other lotus and virginiana. The Korean graft has been vigorous, well over 6 feet tall, but each year has dropped its fruit. This year, after taking off vigorously, it has died back some (while the rest of the tree is thriving) and of the many fruit set, only a few small ones remain. The Wase Fuyu, which is not supposed to be compatible with lotus has never been vigorous and this year I noticed blackening of the leaf veins, a typical but nonspecific finding in KSD.
So two thoughts: One is that this observation somewhat supports the idea that KSD may not be exclusively found with virginiana rootstock. The other is that if known incompatibility manifests with signs similar to what's observed with KSD, there's more reason to believe that the disease is based upon incompatibility rather than infection.