Twidder

[treevet]

There are many sophisticated minds that frequent this part of the forum but maybe not enough exchange of info and opinions. Why?....Who knows. But I thought a thread like this might entice some exchange with less apprehension.(?)

Anyway, how about if any thought (of some complexity) that you may have that might ignite some intercourse (intellectual) that you put it up here if you aren't sure if it will carry a thread.

If it does appear to be thread worthy we can break off with it and start one. If not maybe (or maybe not) a comment or 2 will suffice or just the thought or question in and of itself will provoke some consideration and be worthy anyway.

Well here goes a starter...

Late last fall I noticed a broken limb in an ash from a major storm here just a week prior that when I bucketed up there it had some vague borer holes most with woodpecker involvement. Immediately I suspected EAB because they were in a completely healthy branch and they were in the top of the canopy (know indicators). I spoke with Dan Herms about it and sent him some picts.

He identified it as another borer. I asked if the tree would exhibit weakness so soon after breakage (1 week). He said most assuredly so. This surprised me.

Early the next spring a blow went through and a small redbud I had planted on a property broke at a co dom. LESS than a week later the interior limb flagged and shortly thereafter sunken cankers*** appeared all over the stem of the co dom. This limb being a significant part of the interior canopy could easily be salvaged with a couple of bolts. I took it back to the parent inside the cankers and am hoping for compart. to do its thing.

This again surprised me as to the speed which infection (and previously infestation) takes place.

I see this as somewhat thought worthy as often treatments are hemmed and hawed about before action is initiated by both the arb and the HO.

Love to hear some thoughts/observations on this "time is the essence" scenario. Here are a few picts of the redbud.....

***Botryosphaeria dothidea

 

[treevet]

 

[treevet]

 

[treevet]

Why has bark tracing or wound scribing fallen out of favor? Shigo said let em alone. Let the tree establish the boundary (compartmentalize is not the correct term here as we are talking callus).

Bark tracing was a staple of tree practices from maybe the forties or earlier until just relatively recently. I once was on a job on the Johnson and Johnson estate in Lawrenceville (Princeton area) NJ where a fellow employee spent 0ver 8 hours bark tracing a canker on a Blue atlas cedar only later to have the semi mature tree flown out with a helicopter and another put in its place.

Say a tree is hit by a car. You have a very jagged wound with all kinds of necrotic tissue mixed in with some viable tissue. My inclination is to trace the wound with a wooden mallet and a number of very sharp chisels and establish a perimeter of a clean edge of the wound. Tree surgery in one form you could call it.

What is done beneficial here? Well despite sacrificing some healthy tissue you are ridding the tree of an infection court in the dead tissue that is protruding in many directions that is a food source to fungi not to mention a vector to healthy tissue for pathogens. What is different from making a natural pruning cut on a dead stub? The dead stub is to fungi as candy is to a human in a Shigo analogy.

 

[treevet]

Yesterday I was just beginning to review the cd I recently bought "A collection of over 5000 items from research and travels worldwide over a forty year period" From Trees, Associates and Shigo.

Viewing the section on Armillaria Dr. Shigo muses...."I believe that the spores of Armillaria pass through the guts of fungus gnats before they germinate."

Maybe Dr. Shigo did not have the opportunity to pursue this further before passing but I know that an entomologist and a mycologist (and both professors) at Ohio State U. that I have intermittent email contact with are working in conjunction on studies in the interaction of insects and fungus.

This seems very interesting. Just for example could the premise by Dr. Shigo lead to a best practices in the control and or prevention of the difficult (read impossible) to eradicate Armillaria?

 

[Urban Forester]

Did Dr. Herms say if it was 2 line chestnut or banded Ash borer? Both have intense small areas of infestation. That could've been why it broke at that point. I've noticed a rather ho-hum attitude when we label a pest "secondary". It seems we move to the stressor that brought the secondary pest in and forget(?) about the pest. In some cases isolated cases of stress in a branch are nearly impossible to diagnose and what would be the correct "treatment" to improve health in ONE segment of a tree? Is there even a NEED to improve health, this infestation maybe be more a natural event rather than a lack of health...When we deal with a primary pest we are more detailed oriented in learning its life cycle, control options, etc.

I have seen a massive increase in Botryosphaeria in redbuds in Michigan in the last 2 years. 4 trees this year were positive, more than I've ever seen b4. While we tend to look at Redbuds as weak "ornamental sisters" they really have quite a diverse growing range and can survive alkaline soils that would make many "native"(?) trees weak. I believe that the mild winters (in Michigan) the last 4 or 5 years has allowed many organisms to survive in greater quanities. We have also seen high humidity in the spring with alot of rain, this may also contribute to the spread.

I have no doubt the the insect vector or "contribution" is viable as a method for vectoring Armillaria. Blue stain fungus, pine wilt, oak wilt, DED are all vectored that way. It would not suprise me to see Armillaria is also. I think that the above paragraph regarding secondary/primary pests ties in nicely here. Are all the little wood beetles/weevils that we look at as secondary really more of a problem than we believe. Should we label any pest as truly secondary in the urban forest, or are they more of a "lesser primary"?

Interesting topics, I'll be following this closely as the Rebud/Armillaria issue is something I'd like to know more about.

 

[treevet]

Thanks for your input Urban Forester. Dr. Herms could not tell from the picture what it was but was able to discount EAB (I remember dissecting it and sending that pict as well). The limb, maybe 6 inch in dia. was broken from a severe storm that blew through here. All other large limbs in the canopy had no evidence of involvement. It was obviously from the trauma and exhibition of weakness or defenselessness that encouraged the attack. (this has been described as an odor emitted from the phloem). Like I said I was boggled by the immediacy and accuracy of the attack.

This was also the case in the redbud infection and I will keep you posted as to the trees ability to wall off this infection or if I removed the inoculum when I removed the cankered limb. It will be easy to tell and I will post a picture.

You mentioned treating a portion of the tree. Dr. Shigo often considered this when speaking to us.

I agree in not labeling any insect as secondary in virulence but maybe only secondary in chronological order.

It is Dan Herms and Enrico Porfuno (pls excuse if misspelled) that are working in conjunction I believe on a grant.

Also Pls. do not just continue to follow this thread but rather it would be a pleasure to hear your thoughts on any subjects.

 

[treeseer]

Why has bark tracing or wound scribing fallen out of favor? Shigo said let em alone.

Umm, actually he described bark tracing/excising in detail. do you have a citation? The December Detective Dendro case referred to several quotes of his. I've tried it on small Bot cankers wiht mixed results. With big cankers i prune them out like you did. Yes spread can be scary fast.

maybe you could have one thread on Bot and another on Armillaria; too confusing otherwise.

Redbuds bred for color are disease prone, like maples bred for color.

 

[treevet]

Umm, actually he described bark tracing/excising in detail. do you have a citation? The December Detective Dendro case referred to several quotes of his. I've tried it on small Bot cankers wiht mixed results. With big cankers i prune them out like you did. Yes spread can be scary fast.

maybe you could have one thread on Bot and another on Armillaria; too confusing otherwise.

Redbuds bred for color are disease prone, like maples bred for color.

Start a thread on them yourself please. Just trying to ignite some interest as there are some great minds that post here and not enough intercourse (verbal ).

Bred for color ....prone to disease? I have noticed equal opportunity on colored cultivars. Any data on that one? (not Dendro stuff....ie, you quoting yourself).

 

[treevet]

Umm, actually he described bark tracing/excising in detail. do you have a citation?

Citation mainly directly from his mouth. I sat in front of him for hundreds of hours. He favored letting the tree establish callus rather than the arborist establishing a phantom line much involving guesswork.

"A New Tree Biology", pg 548 "There are many other tree treatments and problems....drain tubes, climbing spikes, increment borer wounds, tapping wounds for sap, scribing or tracing wounds,......."

"Tree Pruning" page 51...."Do not scribe living tissues above and below ......

make scribing cuts as shallow as possible. Do not enlarge the wound....."

When you think you are tracing/excising the canker infection (or others) the reality is more likely the tree walling it off with its own defense system.

 

[Ed Roland]

I see quite a bit of Seiridium on cypress here. Even some botryospharia. Bot cankers seem to exude less and perhaps that is a distinguishing feature prior to a path report but whats the dif? With no real fungicidal chemical controls we are left with excising the cankers and possibly treating that area with oxidation. Small infections of erwinia cankers could be managed this way without applying something as toxic as Kocide, see ice nucleation. D Mc recently showed me some data on the relationship between Pseudomonas and rainfall. A chemical that kills Erwinia infections will also kill Pseudomonas. Interesting stuff.

Guy, several weeks back you led me to the practice of heat treatments on cankers. Looks like temps of 160 degrees is effective. Since we want to use the least toxic method when practicing IPM I wonder if applying heat to cankers is better for the tree than tracing or scribing? Same? Worse?

Should there be a butane torch in my tool kit?

 

[treeseer]

" Since we want to use the least toxic method when practicing IPM I wonder if applying heat to cankers is better for the tree than tracing or scribing? Same? Worse?

Both, it depends.

" Should there be a butane torch in my tool kit?

Yes!

Dave check the bottom of p 363 in ANTB, and elsewhere. No hard and fast or universal rules on this, no dogma please.

:thanks:

 

[treeseer]

" Since we want to use the least toxic method when practicing IPM I wonder if applying heat to cankers is better for the tree than tracing or scribing? Same? Worse?

Both, it depends on pathogen, host, condition etc.

" Should there be a butane torch in my tool kit?

Yes!

Dave check the bottom of p 363 in ANTB, and elsewhere. No hard and fast or universal rules on this.

:thanks:

 

[treevet]

"

Dave check the bottom of p 363 in ANTB, and elsewhere. No hard and fast or universal rules on this, no dogma please.

:thanks:

I agree he did flip flop at times but they were flip flops based on new research. No dogma from this old dog. Like I said I still scribe and have been since 1969, I am just a little more judicious about it as it was all the rage to stick a chainsaw in there and make those perfect elliptical shapes that are no longer in vogue. I am talking with upper echelon tree services too.

Shigo had no mention of woundwood as opposed to callus in ANTB but he did in his later MA and from then on.

I remember once tracing a huge canker way up in an oak and the foreman kept pushing me ('70ish) on time. I said do you just want me to fake it? He did.....so I did (tree paint included of course).

 

[treevet]

With no real fungicidal chemical controls we are left with excising the cankers

I share your frustration so often after identifying the infection I often contact a mycologist and we commiserate in the helplessness of being able to do little or nothing.

Guy, several weeks back you led me to the practice of heat treatments on cankers. Looks like temps of 160 degrees is effective. Since we want to use the least toxic method when practicing IPM I wonder if applying heat to cankers is better for the tree than tracing or scribing? Same? Worse?

Should there be a butane torch in my tool kit?

Seems like more collateral damage with the torch. Any data on this Guy? Also seems like pathogens that have breached all but wall 4 would become impervious to this treatment (as they would to topical bark tracing).

 

[treeseer]

"we commiserate in the helplessness of being able to do little or nothing.

Yeah this happens a lot, sometimes because folks feel limited to the EPA-tested and -approved treatments. Trouble is, EPA does not test those treatments that are not submitted, and who would spend the $ to submit a treatment that does not yield a profit? Yes we have to obey labeling laws but those are not as limiting as some (who do not read them) think.

ok attached is one citation--no damage to those young trees noted.

"seems like pathogens that have breached all but wall 4 would become impervious to this treatment (as they would to topical bark tracing).

yes it depends on how hungry for wood the pathogens are, and defenses, and and, but if circumferential spread is halted that seems to be a good thing. perhaps the genral goal is to deny enough resources to the pathogen and isolate it so it starves and dies or at least goes dormant.

 

[treevet]

Fascinating article Guy. It seems like the heat treatment is the best option in this case for numerous reasons especially in the re treatment phase. The only negative noted was "long term effects are unknown". Wonder if new data since this 2001 paper have eliminated this concern.

Advantages....Less equipment needed; slightly faster; control is at least as good if not better; ease of treating gall regrowth required; simplified sterilization of tools.

"Surprisingly, the heat treatment gave nearly complete control of galls that were three fourths the way around the trunk while the surgery/chemical treatment resulted in less than 40 percent control. Overall the heat treatment resulted in 16 percent better control of galls than the surgery/chemical treatment."

Since the 40 % control in this specific treatment was reduced to 16% by other specific treatments maybe a combination of treatments should be observed?

 

[treevet]

This may also be a consideration some day

http://en.wikipedia.org/wiki/Laser_surgery

It is interesting how diseases are regional although the climate may be similar. Living in New Jersey decades ago we encountered Crown Canker (Phytophora cactorum) on dogwood on a daily basis, here in Ohio I have yet to find any existence of it. We used to excise the canker if it was not near to girdling and as mentioned in this Cornel informational, we would take it well beyond the stain/discoloration to healthy tissue in hopes of compartmentalization.

http://plantclinic.cornell.edu/FactSheets/collarot/collarot.htm

We have Black walnut in abundance in our vicinity here in Ohio but I have yet to encounter Crown gall.

 

[D Mc]

Guy, several weeks back you led me to the practice of heat treatments on cankers. Looks like temps of 160 degrees is effective. Since we want to use the least toxic method when practicing IPM I wonder if applying heat to cankers is better for the tree than tracing or scribing? Same? Worse?

Should there be a butane torch in my tool kit?

As you know, WW, I am a fan of this technique, but I don't believe the 160 deg temperatures in farenheit you stated would be sufficient. Where this would kill the contacted pathogen, it would not, IMO, sufficiently alter the remaining wood structure to prevent reinfection. Pathogens, by the hundreds, are ubiquitous with the phyllosphere. They will be there to some degree or another and can become opportunistic (apparently on a whim) so my thought would be to alter the freshly excised tissues with fire hardening.

Not exactly a new concept. Prehistoric man had this figured out, even witout citations.

At approximately 300 deg F, cellulose starts to degrade. That's the little puff of smoke you see. Lignin, being a polymer, folds back on itself and bonds with the other remaining chemicals available within the tree (phenols, resins, etc). This creates a zone of altered cells much less suitable for infection.

So in the case of localized infections this technique may hold a lot of promise.

Dave

 

[treeseer]

"Pathogens, by the hundreds, are ubiquitous with the phyllosphere."

Phyllosphere; neat paradigm to think in. Maybe excising decay while respecting boundaries is a way to reshape that sphere and starve the pathogen.
Along with tree health invigoration, of course.

" my thought would be to alter the freshly excised tissues with fire hardening.
... Lignin, being a polymer, folds back on itself and bonds with the other remaining chemicals available within the tree (phenols, resins, etc). This creates a zone of altered cells much less suitable for infection. "

Great description; hope I can steal/borrow some of that...

Sounds kind of like the "steeling" that naturally takes place in exposed Q. virginiana wood. Unbelievably hard and very resistant to rot, from all indications.

re data since 2001, good question; I wrote the authors, will fwd replies.