Graft rejection is another consideration. I have a large multi-graft persimmon tree with kaki, hybrids, and virginiana. This tree has rejected all the kaki and nearly all of the hybrids. The only hybrid remaining is a 75/25 virginiana/kaki āmale Rosseyankaā. I strongly feel graft rejection on D. virigniana takes place about 20% of the time. However, so far Iāve been able to graft virginiana on these problematic rootstock.
In other words, a safer bet would be to avoid the hybrid interstem on D.V. grafted to D.V. rootstock. Go with a small virginiana or hybrid cultivarāor simply prune to keep small. I should add, there are many reports of kaki on D.V. rootstock for very long periods of timeāmany decades. Itās how the cookie crumbles, and, possibly, a severely stressed tree will reject the graft as an immune responseāpure speculation.
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Sometimes if you are lucky and thing works out well. Here is my D.V root stock with 9 years old Nikitaās Gift then topworked it last year to Rossyanka and topworked it again this year to JT-02. So I got 3 Hybrid interstems on this tree now. It growth almost 5 feet since May on a real large 9 years old root stock.
Tony
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I wondered if Rosseyanka as an interstem wouldnāt be as cold hardy for you in zone 5b without winter protectionā¦depending on the size of the rootstock.
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If the trunk is old and large enough then it will handle the cold well. The Nikitaās Gift and Rossyanka interstems survived last Winter low of -20F without any protection,
Tony
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Iāve wondered if the chromosome number of the D. virginiana rootstock (northern race = 90 chromosomes, southern race = 60 chromosomes, D. kaki = 90 chromosomes) has any effect on graft rejection. I have a large male D. virginiana in my yard that sends up root suckers everywhere. Iāve had no success grafting to any of those suckers, and Iāve tried at least 20 times. It doesnāt seem to matter if I transplant them away from the main tree or leave them attached. Most of the grafts seem to take initially and then die back in a month or two, after theyāve put out a few new leaves and grown 6 inches or so. On the other hand, Iāve had good success grafting to the D. virginiana root suckers from the rootstocks of grafted kakis I originally purchased from Edible Landscaping. Judging from the fuzzier leaves on most of these rootstocks, Iām assuming these are the 90 chromosome northern race D. virginiana, while the tree in my yard is the southern 60 chromosome race. I asked Michael McConkey of Edible Landscaping about this, and he said that heād never observed any difference in grafting success between the northern and southern races when used as rootstock for kakis. I know @cousinfloyd has successfully grafted to the southern D. virginiana race, and presumably others have too. It might be that individual D. virginiana trees make for better or worse rootstocks due to factors that we donāt really understand yet.
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I have observed this graft rejection , mostly on āolderā D. Virginiana rootstock when trying to graft Asians on top.
Often the graft will take and push good growth, then suddenly the veins start to turn black and die.
Same scionwood, on a one year seedling ,no problems.
Itās as there is some immune response and rejection on a older tree, ( sometimes),
And have regrafted with a American variety on a failed Asian graft. With good takes.
Convinced itās not my technique, something else going on?
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Iām not convinced that the wild persimmons on my place are 60 chromosome. I didnāt know there were any visible attributes like fuzzy leaves to distinguish between 60 and 90 chromosome strains. I do know that someone in eastern Tennessee (kind of near Asheville, NC) ā and I think Hillbillyhort in WV, too, right? ā is able to grow a bunch of the popular named varieties of American persimmons and get seedless fruit, but I get fully seeded fruit from varieties like Meader and Ruby here, and a friend in nearby Winston-Salem gets fully seeded fruit from Yatesā¦ Have you gotten any fruit from named American persimmon varieties at your place yet, Ben? Theoretically if youāre in the 60 chromosome area you ought to get mostly seedless fruit, right? Iām not hopeful for you, though. Itās a poor guess, but my best guess is that my wild persimmons are 90 chromosome. What else could explain me getting all fully seeded fruit?
But even if I am in the 60 chromosome region as conventional wisdom suggests (south of the Ohio River) ā and Iām pretty close to due south of Hillbillyhort in WV thatās apparently far enough south to be in the 60 chromosome region ā my grafting failures are inconsistent like Hillbillyhort has described. Some grafts take. Others donāt. But one thing that seems consistent is that if an Asian or Asian hybrid graft fails (typically by initially growing and then turning black and dying after putting on 6-12" of new stem growth) subsequent grafts on that same rootstock seem to never take. Maybe itās an old rootstock issue like Dave is guessing. Almost all of the rootstocks Iām grafting onto are volunteers that have been mowed 1-3 times per year for decades, so although the top growth is only 2-3 years old, I think the roots on the trees Iām grafting on could be 50 or 100 years old. Most of the volunteer trees Iām using as rootstock grow in clusters that I believe are all root suckers off of the same root system. Iād guess only about 10% of my Asian grafts show signs of incompatibility like I described.
This year, for the first time, though, I had some branches on established trees (one Saijo, one Sheng) show the same symptoms, but in neither case was it the whole tree. These are trees I grafted 4-5 years ago that never showed any symptoms before. The Saijo was a forked tree, so I just cut out the whole fork with the diseased looking branches. I havenāt done anything with the Sheng yet. Itās curious to me that this happened this year, because we had a mild winter and a spring exceptionally free of any late freeze/frost events, so there doesnāt seem to be any correlation at all to winter injury.
Whatever problems youāve had, Ben, my guess is that they donāt have anything to do with 60/90 chromosome differences, but I donāt have a good guess as to what else it could be.
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Iām in DEEP S. Georgia. We should only have 60 chromosome cultivars down here. All the seedlings I use should be of the 90 chromosome type. Kaki on either rejects at about the same %. If I graft a 90 chromosome onto a 60, Iāve seen some evidence of an immune response, but the graft survives and even thrives.
This is true for me initially, but as time goes on the % increases.
I believe this to be a result of climate. All the fuzz cooks off of the leaves/stems down here.
The reports of a slow spreading habit with certain cultivars may be climate or rootstock induced. Persimmons are not simple. A lot of factors come into play. JT-02 supposedly has a slow spreading habit.
This 2019 JT-02 graft was actually pruned back to a few inches a couple of months ago because I nearly tore the graft apart when I installed the support bamboo. This is the regrowth.
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Do you mean simply because grafts that failed once are more likely to fail the next time?
I canāt recall where I read about distinguishing between the two races of D. virginiana, but all of the new leaves on the local trees I see in my yard and in the area are shiny and red. The root suckers from my grafted trees have a white fuzz on the new growth and look quite a bit different initially. The mature leaves look very similar, though.
I donāt have any improved D. virginiana varieties, and my hybrids are still too young to fruit. So I canāt answer your question about seeded fruit.
Iāve had the same experience as you and @Hillbillyhort where Iāve never been able to regraft kaki scions on a D. virginiana rootstock that has died back with the black veins. My three year old Saijo and Miss Kim (purchased from Edible Landscaping) both died back this spring after initially putting out a lot of nice growth. The black veins and wilting started on one branch and then spread. It couldnāt have had anything to do with cold damage because there was no winter dieback after a mild winter, and the initial growth was vigorous. They were both very healthy trees last year. Iāve had the same thing happen with a few other grafted kaki trees from Edible Landscaping, but other kaki trees from them have been fine. Maybe it has something to do with delayed graft compatibility, but I donāt really know.
I think youāre right that either the 60 or 90 chromosome rootstocks ought to be fine based on reports from those who have done much more grafting than me. The only local D. virginiana tree Iāve ever used as rootstock is the one in my yard, so zero success with that one tree doesnāt tell me anything about the 60 chromosome race in general.
Since Iāve had good success grafting onto the suckers of my largest grafted trees, and I have enough new suckers from those trees each year to cover my rootstock needs, I havenāt experimented with any other rootstocks.
and I have no idea if the wild D. virginiana in my yard is really a 60 chromosome tree - I was just assuming it was since the root suckers look different from those of the grafted trees I have in my yard.
Hereās a quote from Lee Reichās Uncommon Fruit for Every Garden:
There exist two races of American persimmon, a ninety-chromosome, ānorthernā race and a sixty-chromosome, āsouthernā race. The ānorthernā race is native to the upper Midwest of the U.S. and is the earlier ripening and more cold-hardy of the two races. Also, the pubescent leaves and larger fruit (which occasionally are bluish) of the ānorthernā race contrast with the smooth leaves and smaller fruit of the āsouthernā race.
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For me, if they fail once, there is a high chance kaki will fail again.
I mean to say the first year grafts show a rejection rate of approximately 10%. The next year, a small percentage of the āsuccessfulā grafts may also failā¦and again the next year.
I still feel D.V. is the best option for me unless someone is developing a clonal hybrid rootstock.
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Thanks for clarifying that. In hindsight I should have understood that to start with, but I didnāt.
Can you put any kind of approximate numbers to the subsequent year failures? And what are the symptoms of subsequent year failures? Does the diseased looking growth start in one part of the tree and then spread?
Have you or anyone else seen the sort of symptoms Hillbilly and I have described affect part of a tree without proceeding to kill the whole tree?
In my experience it seems to be 100%. Have you had any grafts take and survive a year or more (that you can remember for sure) on rootstocks that failed once with symptoms at all like Dave and I are describing?
Iāll try not to be long-winded.
All I can give is a rough estimate of what seems to occur over a few years with a significantly lower rate of failure the older the tree getsāmeaning, the older tree which has been previously grafted and whose graft has undergone subsequent growing seasons.
From what Iāve seen, the entire treeāalbeit small treesāhas already displayed lackluster growth for its first growing season. When growth starts in the spring, the entire tree above the graft union shows the symptoms described by many others in this thread. Dissecting the tree reveals completely normal growth below the graft union and the tree continues to grow normally from this point. In fact, attempting grafts of 100% D. virginiana prove successful. Unfortunately, persimmons respond to any type of injury by production of tanninsāif memory serves me correctlyāand the accompanied black streaking. This fact leads many to jump to conclusions without actual lab testing.
The above should help with your third and fourth
question:
Another thought: the large persimmon tree I described in one of my previous posts literally has a pure kaki and pure virginiana grafted side-by-side onto a 60 chromosome rootstock (presumably). This tree was grafted around 10 feet high. kaki=fail D.V. =success
Yes, I would agree it is somewhere around 100% for pure kaki. You must consider that poor graft healing would probably present in a similar manner. My naivety led me to believe I could graft hybrids onto these failures, which resulted in about an 80% failure rate. So far, it would appear the more virginiana %, the higher the takeāsorry, no exact numbers to offer.
One other thing: I think it is important to try to limit variables. This is one reason I grow my trees in elevated root-pruning containers in a soil-less mix for the first growing season. Sometimes, in the subsequent growing year I upgrade to a 7-gallon fabric pot to get another year of unhindered growth and reduced disease pressure.
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90 chromosome male D.virginiana trees somewhere in your area seem like the most likely explanation to me. Have you ever noticed those seeds sprouting? Just curious if theyāre viable.
For what itās worth, I found this poster describing the goal of having improved 90 chromosome female D. virginiana pollinated by wild 60 chromosome males:
PomperASHS2017_a.pdf (447.1 KB)
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From Epigenetic Regulation of the Sex Determination Gene MeGI in Polyploid Persimmon
While the diploid persimmon D. lotus is dioecious, the closely related species Diospyros kaki contains mostly autohexaploid trees, with varieties that are either fully female or monoecious, i.e., each tree bears both male and female flowers. With the exception of a few female cultivars that occasionally bear male flowers (Akagi et al., 2014b; Yonemori et al., 1993), all monoecious trees tested so far carry at least one copy of the Y chromosome (presence of the Y-specific OGI gene), while the female-only trees do not (Akagi et al., 2014b).
I know we are talking about D. virginiana here, which seems to behave similarly to kaki. I believe D.V. to be entirely female, monoecious, or entirely male. These entirely male trees seem to dominate the landscape around here. To further complicate the matter: if you read the entire linked paper, youāll see that it is quite common for male flowers to TURN femaleāgenetically male flowers becoming female and bearing fruit. This is in addition to the entirely female trees that occasionally throw male flowers.
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I put together a web page detailing some persimmon genetics. There are a few typos and redundancy, but I was rushed for the final.
https://studentweb.mga.edu/david.dacalio/pac/index.htm
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