Fasciation Street Trees - Virtually All. Guesses ??

[treeseer]

MV "In this case, they are stunting quite a few apical tips and affecting the structure. "

Affecting structure for the better; curing codominance.

This fasciation does not appear to be damaging tree stability or health in any way. On the contrary.

Agreed?

Does anyone see a good reason to prune them out?

 

[Toddppm]

They're freaky and they look weird, TOP THEM ALL!









J/k, relax, I wonder if they were cut out if it would reoccur in the same stems?

 

[M.D. Vaden]

MV "In this case, they are stunting quite a few apical tips and affecting the structure. "

Affecting structure for the better; curing codominance.

This fasciation does not appear to be damaging tree stability or health in any way. On the contrary.

Agreed?

Does anyone see a good reason to prune them out?

Yes - we agree that they are not really damaging the trees much, if at all.

There is some "wedging" and rubbing of bark on some others where the fasciated growth tweaked to the side and inserted itself through some tightly spaced limbs. But it can all be corrected.

The main thing I find interesting, is the number of trees it's happening to in one localized area.

The fasciations that are apparently not causing problems to form, could probably remain. It seems to add character. The color is really nice too. It's like ornaments.

 

[M.D. Vaden]

Here is one more.

This where the 20 x zoom is handy.

The tree top here is about 20' to 24' high.

 

[M.D. Vaden]

Mainly an experimental crop to see how much or little detail a 20 x zoom point and shoot camera captures from 20' away.

This is 600 pixels that was cropped from a 3600 pixel wide image.

Freehand - no tripod.

Actually, I think this is from 30' away. It was about 20' straight up, but I was standing off to the side.

 

[John Paul Sanborn]

Looks like they come from contemporaneous budding, another aspect that makes me think it is outside influance vs. genetic.

 

[treeseer]

Looks like they come from contemporaneous budding, another aspect that makes me think it is outside influance vs. genetic.

I don't get the difference.

why would this budding not be caused internally?

 

[John Paul Sanborn]

It seems to me that if it were of an internal causation you would see it in different year growth sequences, not in several trees in contemporaneous growth sequences.

I could see mutation occurring in several trees of similar parent stock, but for them all to get it at the same time is highly unlikely. Add the reversion to norm on some of the fasciated twigs and the event looks more exogenous. If they are all at a similar height, then I would lean towards an late frost. This would be similar to a tattering event with leaf buds.

 

[M.D. Vaden]

John I think I see some two year old growth affected. What do you think?

There were some bigger ones like what you highlighted, that do look a couple of years old.

 

[John Paul Sanborn]

I noticed that too, not my comment on reversion to norm.

If it were a frost, cold weather mite it would more easily explain the large set effectation.

Having it be a mutation that will cultivate true would be cool. I'd take a cutting to a local propagator just to see what happens.

 

[treeseer]

Having it be a mutation that will cultivate true would be cool. I'd take a cutting to a local propagator just to see what happens.

Good idea. Plenty of growers in OR, and redmaple is such a popular plant it seems there would be a ready market for a quirky selection. This was done with Cryptomeria japonica 'cristata'. That is now a popular plant.

Nice job on the pic Dan. In the absence of definite clues supporting an external hypothesis, I'm still tending to internal causation. It's not '"damage", so only those growths that impede good development as Mario notes should be pruned out imo.

 

[treesandsurf]

Sent an e-mail to a hort professor I had at UH; here's his response:

"Jon:

There is probably a hormonal basis for fasciation, probably cytokinin-related, causing the apical meristem to develop multiple growing points. The condition of "habituation" comes into play, wherein the tissues continue this growth phase even when cytokinins are withdrawn.

Some insect feeding may possibly stimulate this, as well. You may notice some leaf spots where insects have fed and it is surrounded by green tissue, Either the insect injects its own version of cytokinin or the plant responds to some substane injected by the insect. If the feeding is done at the tip of the plant and there are enough insects doing it, the response may be the production of cytokinins and fasciation. Thus, if the right insect is present, a series of plants of the same genotype could be infested and develop the fasciation. If it is not a translocated response, pruning might eliminate the growths.

As the wikipedia entry notes, the trait may be carried on, but it is not clear whether it is truly genetic (change in gene expression that is inherited) or epigenetic. Some plant species may be more prone to fasciation than others. Many crested forms of cacti are the result of fasciation and are often re-propagated by collectors by grafting. I have one plumeria that seems particularly susceptible to fasciation, with some branches very fan-shaped (see atachments).

Also, there are examples of fasciation induced by phytoplasma organisms. A lot of the distortions caused by the Aster Yellows phytoplasma (previously thought to be a virus) are fasciated or witches' broom type growths.

An interesting questions relative to the arborist's observations is whether the fasciation reoccurs if the fasciated part is pruned away. New buds that develop might not show fasciation if there is nothing (like an insect) to stimulate it, or if the effect is systemic due to excessive amonts of cytokinin, it may reappear.

Ready to come back and enroll in grad school?

Aloha,

Richard Criley"

 

[John Paul Sanborn]

That was fun. I wish other threads where one party took a countervailing position would remain so civil.

Give Richard our thanks for taking the time.

 

[John Paul Sanborn]

I read some of these papers and started to go crosseyed.

http://www.scirus.com/srsapp/search?q=cytokinin+fasciation&t=all&sort=0&g=s

Here I changed the search for genetic fasciation
http://www.scirus.com/srsapp/search?q=genetic+fasciation&t=all&sort=0&g=s

Has anyone used Salix udensis 'Sekka', Japanese fantail willow?