Overall this is great work. But you should probably label the graph “Ancestry of Reported Hybrid Persimmons in the U.S.” You are normally meticulous about proof. But the entire left half of this graph represents varieties reported by one grower and descendant from one supposed kaki. The grower, who admittedly has made huge contributions to the advancement of persimmon culture in the U.S., is nevertheless known to be sloppy in his identification of varieties as hybrid and has had a stroke that has demonstrably reduced his reliability as a reporter. The supposed kaki “Hokkaido” is known to be grown by only two people – the named grower and one other. The other grower says that he never produced a DV x DK hybrid. So at minimum, the entire left side of the graph is “not proven.”
I can only imagine what serious Ukranian breeders must think. They worked on persimmon breeding for almost a century. In all that time, they produced 1 direct cross of Virginiana x Kaki. Meanwhile in 3-4 years (2012-15), Cliff produced >40 which have been sitting unheralded in his nursery for the past decade.
IMO, you can break it into 10 degree segments with some that are only hardy down to 10F, some hardy to 0F, some to -10F, a few hybrids to -20F, and very cold tolerant down to -30F. To the best of my knowledge, D.V. is killed at temps below -40F but that is subject to verification. I would probably use a cold tolerance rating of
1 ~ >=10F
2 ~10F to 0F
3 ~ 0F to -10F
4 ~ -10F to -20F
5 ~ -20F to -30F
6 ~ >-30F
Map verification shows that each 10 degrees a tree can stand increases the cultivation range about 8 degrees latitude subject to topography where mountains affect the climate. I can for example usually grow anything that is hardy down to 0F in the bottom edge of Tennessee 4 miles from the Alabama state line. This year we had a freeze the 20th of December that went down to -4F. In the past, I have seen -12F once and about 70 years ago we had -20F.
@disc4tw
Superossiyanka is a documented bud sport of Rossiyanka.
It appears there are two different Sovietski at England’s Orchard. One is an older D. kaki female (HF 3.49) while the newer is a D.hybrid (1.3), documented elsewhere as a seedling of Superossiyanka.
Pamjat Pasenkova is also documented as a seedling of Superossiyanka.
I had ‘Hokkaido’ from Cliff when he first offered it - maybe 20 years ago. I THINK he said it was the cold hardiest pure kaki he had. It didn’t make it through it’s first KS winter.
I don’t know whether they are from the same scionwood or even the same supplier.
England’s has been a USDA registered nursery for decades. I don’t know if they were receiving persimmon material directly from the Ukrainian research institutions. Certainly they are eligible.
According to the labels, Cliff produced the reported hybrids roughly 10 years ago. “Hokkaido” was the presumed male parent, so technically I should have written DV x Hokkaido. We have no way of knowing whether your 20-year old Hokkaido and Cliff’s 10-year old Hokkaido are the same variety.
I’d be interested to know who else has Hokkaido other than you, Cliff and Bass.
Here’s a link to our updated list in Google Sheet format. The link is “live” to the document I edit. It is read-only, but you can use the Google Sheet “File” menu to make an editable copy, print, and download to various formats.
Also, here is a link to the compressed folder containing various references and the software I’ve written with Mathematica® to generate the parent-sibling diagram:
I’ve been sent paperwork from Cliff a couple of time with a path toward USDA-ship I guess. They’ll pay for breeding research; like all of it.
cliff (for the record and i’m about out of fuel) told me verbatim my sovietski at my house is definitely a hybrid. my other Sovietski at the farm is the QUOTE from cliff, “same thing.” He went further to say they are both hybrids probably to get me off the phone.
<< 2021 winter cold blast of -20°f at night for a week killed most of my hybrid persimmon seedlings and advanced pawpaw seedlings. Yet 5 year old ‘Kasandra’, ‘Zima Khurma’ and ‘Mikkusa’ were unscathed.>>
I don’t know where you found this information.
Pamjat passemkova is an F2, if it was a Rosseyanka mutation he would be an F1.
He can’t be a superosijanka seedling either.
Superosijanka is probably just Rosseyanka. Would be an earlier and larger Rosseyanka mutation. The person who got it in Ukraine died in an accident. The variety was unveiled much later than Pamjat passemkova. So sowing impossible.
Since then, all the people who have this variety don’t talk about it anymore… if it’s unknown, not distributed, there’s a problem. To be certain I will put a Rosseyanka and a superosijnka next to each other…
Richard, thanks for putting this together. It’s a beautiful representation of prodigy; Mathematica® is the perfect name to represent what is currently unknown, Diospyros.
I hope your software is distributed like scions are. (you know what I mean)
(you know what I mean)
DAX 
