I think there’s something very wrong with my multi-grafted persimmon. Any idea what this is? Is it possible to save the tree? Some of the branches still look healthy, but a lot of them look like this.
Are these Asians or Hybrids grafted to D. Virginiana (American)? If so, maybe “Sudden Death Syndrome” (SDS). Search on it within the forum.
No, the rootstock is a fuyu.
well since that fuyu it self is probelly a graft .
(persimmon is very hard to root
it;s likely a secondery rootstock
I think that is KSDS unfortunately. There is an active thread now about it:
It is surprising this is not better-known given how so many people here are having issues with it. I just took out two trees with it myself.
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Looks like KSDS is definitely the culprit. Got the black veins on the leaves. I got this after grafting a bunch of scions from Really Good Plants; not sure if this is a disease that’s transmitted by grafts or what.
Is this disease 100% fatal? The weird thing is that the grafts from previous seasons still look perfectly healthy, even while the rest of the tree appears to be dying. Is it possible that the tree could survive via those grafted branches?
This raises an interesting question: Can a healthy kaki be infected by grafting an afflicted DV scion? I assume so. If so, I suppose we should avoid such grafts.
It seems there are three paths by which this tree was infected:
- Infected DV rootstock with Fuyu interstem. Infection migrated up the central leader and out the branches.
- Infected DV (or maybe DK) scion on the mutligrafted tree. Infection migrated down the branch, into the central leader and out the branches.
- Infected nearby tree with transmission by insects. Assuming bites on soft tissue, infection migrated down the scion and out, as in #2.
In my naive thinking about SDS, I’ve been focused on scenarios like #1, so I’ve been trying to ensure that my DV rootstock is healthy. I’ve excluded #3, believing that the culpable insects don’t live here. I’ve never considered #2 until now.
Can anybody knowledgeable comment on the probabilities and risks.
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I had the same thing on my tree, which was over 20 years old. I eventually turned to the scientific literature and came upon several articles about a new pathogen that first turned up in California orchards in 2020. It is characterized by black, wedge-shaped cankers particularly at the branch unions and black streaking in the cambium. In my case, the tree continued to bear, though the fruit had lesions if it wasn’t aborted, and it began to drop branches often after a rain when the extra water weight was too much for the weakened unions. I eventually cut the tree down and discovered black streaks in the cambium all the way to the ground. The only cure seems to be to cut out the infected parts before it reaches other parts of the plant.
Here are two articles about the problem and the diseases that are causing it:
https://www.sciencedirect.com/science/article/pii/S0261219424001005
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Also, for what it is worth, I’m not sure that this is SDS, unless I misunderstand SDS. The theory that I have read about SDS is that it is a pathogen carried by virginiana that does not effect that species but that is devastating to kaki, which why trees grafted to virginiana sometimes fail suddently. But that is not what happened on my tree and does not seem to be what is happening here, necessarily. Instead, it appears to be the fungal pathogen, or set of fungal pathogens, identified in the papers above that entered through a pruning wound or through a grafting attempt. In my case, the pathogen was present for two or three years before I figured out what was happening. At that point it was systemic in the tree and I had to take it out. If I had figured out what was happening earlier, I might have been able to remove the diseased wood, much like removing black knot in a prunus species, without losing the entire tree. Or at least that is a conjecture that I wish I could have tested.
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Thanks for the reply! I looked into this a bit myself, and I’m pretty positive that it is KSDS, just given all the symptoms and how it progressed. One paper I saw linked the appearance of the disease (including in Asian persimmon rootstocks) with either extremely low winter temperatures or a late freeze, both of which happened here this year.
The tree is probably toast; all the branches are now dead, although interestingly, some of the grafted varieties held on and resisted for much longer than the rest of the tree. I was wondering whether it was possible for anything to come back from the roots, but now I’m thinking that I should probably just get rid of the whole tree, since the rootstock is clearly not resistant to this disease.
Thanks for the articles; they would have been a lot more helpful if only they had shown results of tests treatments that would halt the progression of dieback into other parts of the tree.
Today after reading these, I decided, since there are remaining portions of my tree still very healthy and even growing new shoots below the dieback on each limb, to sanitize my pruners between each cut, removed each dieing branch below the next healthy new shoot and sealed each Final Cut with liquid silicone. Below are a few pics of one branch end removed.
Dead end chunck
Chunk near the dead end first healthy new shoot
Last chunk removed interior seems in infected
Stub end after cut before silicone sealing
Now I will monitor for the season to see if dieback continues? This is what a more helpful study should do. If anyone knows of a researcher who has found a remedy please advise. Perhaps we should select one for members to engage to solicit such a study!
Dennis
Kent, Wa
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I was going to ask about grafting knife sanitation.
I always use a paper towel soaked in alcohol. Before and after every cut when disease or infection is anticipated
I think the researchers were more intent on finding the exact pathogens that were causing the problem, rather than providing horticultural remedies. The academic discipline, which I took to be plant biology rather than horticulture, seemed to drive the questions that they were answering. But I think your approach to pruning and sanitation is a good one. Let us know how it goes!
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