Acer rubrum: Verticillium Wilt or Self-pruning?

[DeepSouth]

This acer rubrum was collected about 3 and a half months ago as a bare stump. It has since put out a significant amount of branching and appeared to be healthy. About a month ago, it killed off some of its new growth tips and in the past couple of weeks it has completely killed off two branches. The branches initially present with the leaves wilting and dyeing, then they fall off. This happens in the matter of a few days or wilts.

I can imagine one of three things happening:

1. Verticillium wilt seems like a possible contender due to the rapid wilt and leaf drop followed by branch death.
2. Anthracnose is going around in my garden, particularly among the japanese maples, but it really kills off an entire branch so quickly.
3. The tree is self pruning. Perhaps it grew too many branches after collecting in late Spring and can't sustain them all.

My instinct is leaning towards #1, in which case I will throw the entire thing into the burn pit. I separated the tree from the rest of the garden after it killed off the first branch.

On the other hand, I don't want to act prematurely and will solicit advice here first. This is the largest acer rubrum that I have collected and I don't really know how they behave.

First Wilted Branch:



Second Wilted Branch:

 

[Jetson1950]

This acer rubrum was collected about 3 and a half months ago as a bare stump. It has since put out a significant amount of branching and appeared to be healthy. About a month ago, it killed off some of its new growth tips and in the past couple of weeks it has completely killed off two branches. The branches initially present with the leaves wilting and dyeing, then they fall off. This happens in the matter of a few days or wilts.

I can imagine one of three things happening:

1. Verticillium wilt seems like a possible contender due to the rapid wilt and leaf drop followed by branch death.
2. Anthracnose is going around in my garden, particularly among the japanese maples, but it really kills off an entire branch so quickly.
3. The tree is self pruning. Perhaps it grew too many branches after collecting in late Spring and can't sustain them all.

My instinct is leaning towards #1, in which case I will throw the entire thing into the burn pit. I separated the tree from the rest of the garden after it killed off the first branch.

On the other hand, I don't want to act prematurely and will solicit advice here first. This is the largest acer rubrum that I have collected and I don't really know how they behave.

First Wilted Branch:
View attachment 613177


Second Wilted Branch:
View attachment 613178

A fourth possibility is the pathogens (Fusarium, Pythium, and Phytophthora) that cause root rot which causes new growth to wilt, turn black and die. I have to deal with that a lot here when we are getting heavy rain for weeks at a time. It affects my Acer Rubrum much more than the Japanese maples, even with them in bonsai inorganic soil. Here are a couple of examples on real small ones. Haven’t had it kill any, but areas turn black and they lose a lot of leaves. They come back when things dry out a bit.

 

[rockm]

Verticillium isn’t that fast. It can wilt branches but such a rapid progression from branch to branch is accelerated. It’s also a collected tree right? Verticillium is generally a disease in nursery trees that are packed closely together.

It’s more likely fusarium or something more common.

 

[DeepSouth]

Verticillium isn’t that fast. It can wilt branches but such a rapid progression from branch to branch is accelerated. It’s also a collected tree right? Verticillium is generally a disease in nursery trees that are packed closely together.

It’s more likely fusarium or something more common.

Gotcha - yes the branches wilt and die in a matter of days. It's very rapid.

And yes, this tree was collected at the edge of a pond on our property, in the middle of the woods.

If it is fusarium or something similar, do you feel that it is worth trying to treat or a lost cause?

 

[rockm]

Gotcha - yes the branches wilt and die in a matter of days. It's very rapid.

And yes, this tree was collected at the edge of a pond on our property, in the middle of the woods.

If it is fusarium or something similar, do you feel that it is worth trying to treat or a lost cause?

Not worth the trouble. Get another. They’re pretty common. FWIW. This may be a result of ground water splashing into the pot (rain)

I lost two very nice recently collected trees because I left their pots on the ground. Eerily same symptoms as yours. I lost both in days in the same way. The recently cut roots left them open to whatever fungus bacteria etc splashes up from the ground (I used regular prepared bonsai soil to pot them up)
So. I haven’t left collected stock on the ground since and no longer have the issue.

 

[DeepSouth]

Not worth the trouble. Get another. They’re pretty common. FWIW. This may be a result of ground water splashing into the pot (rain)

I lost two very nice recently collected trees because I left their pots on the ground. Eerily same symptoms as yours. I lost both in days in the same way. The recently cut roots left them open to whatever fungus bacteria etc splashes up from the ground (I used regular prepared bonsai soil to pot them up)
So. I haven’t left collected stock on the ground since and no longer have the issue.

Yeah, this is a good point and an error on my part. I collected more trees this year than I had bench space for, so a few ended up on the ground.

I am going to get rid of that maple and get the rest (mostly BC) off the ground onto a makeshift bench.

 

[nuttiest]

Deepsouth -
I think your problem on the first branch is contaminated OVERHEAD water, like whatever was in some organic fert or rainwater or just spores that blew on leaves before a light rain.
The other looks different like mechanical damage.