Live oaks/ wound coat

macswan

macswan

Been here a while
Location
Champlain Valley, VT
I have just heard tell that when pruning live oaks(to be case specific, in texas) you need to paint the wound with sealant or spray paint immediately to prevent oak wilt. What's the concensus on this, best practice or crazy mumbo jumbo?
 
[ QUOTE ]
I have just heard tell that when pruning live oaks(to be case specific, in texas) you need to paint the wound with sealant or spray paint immediately to prevent oak wilt. What's the concensus on this, best practice or crazy mumbo jumbo?

[/ QUOTE ]

You ask an excellent question, and I know your heart is in the right place, but how do I answer an Aristotelian question (either-or) in a huge complexity of facts and conditions?

We've spent hundreds of years in the debates of keeping bad things out by sealing the wounds we make when we use our favorite tools--the saws. The latest saws have "improved" by being bigger, faster, and much more beautiful in the eyes of the manufacturers. To trees however, the circumstances remain the same; continued ripping up small pieces of wood in an expanded and hopefully continuous basis.

Saws service their masters--us, not trees. We may claim different techniques in some "best practice", but where the tooth hits the wood, the physical act is essentially the same.

So, why am I writing in your post? Because the question is still a valid one and a number of alternatives are continually offered.

I'm always impressed by nature in her propagation by statistics: produce a few hundred million and perhaps one might stick. In both simple and complex organisms, she produces billions of spores, and millions of sea turtles. Where ever you might seem to look, you'll find a few of everything. So much for the idea of sealing naughty things out.

As Everett Dirksen might say in a local area with oak wilt, "pretty soon you're talking about real infections." And is any practice ranging from sealing wounds to tool disinfecting, going to be enough of a presence to overcome the statistics of ubiquitous nasties?

Here I become the muttering realist: I don't know; you don't know; and they don't know. And in addition to those of us looking for scientific truth, is an endless supply of people looking to make money in any way possible. Some pursue snake oil with the intensity of others looking to build a mega-church. Some are simple, well intentioned folk, who stick to their guns--and their opinions.

Aren't the Shigo-Neely debates about wound paints also interlaced with the speeds of wound-closure? Two decidedly different issues? And what do the textbooks say? ( http://pnwhandbooks.org/plantdisease/pesticide-articles/tree-wound-paints )

We live in an actual world of most things being "non-conclusive." And we harvest that world to generate revenues and protect our self interests, "There is nothing conclusive about global-warming."

So I'm apparently concluding with a link between tree paint and global warming. That's a stretch even for me, but if you really think about it, it's the same statistical infection...


Bob Walpole with its (still too lazy to correct my voice-recognized name)

PS: And a minor thank-you for letting me indulge in a post-partum Christmas rant. Please do the things that you ethically believe. Spray paint the wound you've just made on a tree; or write a letter to Exxon.
 
Hi Macswan,
My bias is towards no wound paints/dressings at any time for any reason.

That being said, my FS colleague Jenny Juzwik and her research (see http://nrs.fs.fed.us/people/juzwik) has pretty much convinced me to avoid pruning oaks in areas with oak wilt at the time when the nitidulid beetle vector is flying around. That precise time will vary from place to place, but the goal is to not attract the beetles (which carry the oak wilt fungus) to fresh wounds and to subsequently infect them. Your local extension service or landgrant university specialist could probably tell you the calendar time of greatest risk of infection by beetles.

Of course, we live in an imperfect world and cuts are sometimes made when the beetles might be active. Then, and it's hard for me to say this, a thin coat of wound paint has been shown in Jenny's work to be useful. See her little 2011 practical guide (with Joe O'Brien as primary author) at http://na.fs.fed.us/pubs/detail.cfm?id=921.

Keep in mind that much spread of OW is by root grafts, so wound dressings won't help there.

Until the end of September, I was Jenny's boss, and am now proud to be another Forest Service scientist!
 
[ QUOTE ]
Hi Macswan,
My bias is towards no wound paints/dressings at any time for any reason.

That being said, my FS colleague Jenny Juzwik and her research (see http://nrs.fs.fed.us/people/juzwik) has pretty much convinced me to avoid pruning oaks in areas with oak wilt at the time when the nitidulid beetle vector is flying around. That precise time will vary from place to place, but the goal is to not attract the beetles (which carry the oak wilt fungus) to fresh wounds and to subsequently infect them. Your local extension service or landgrant university specialist could probably tell you the calendar time of greatest risk of infection by beetles.

Of course, we live in an imperfect world and cuts are sometimes made when the beetles might be active. Then, and it's hard for me to say this, a thin coat of wound paint has been shown in Jenny's work to be useful. See her little 2011 practical guide (with Joe O'Brien as primary author) at http://na.fs.fed.us/pubs/detail.cfm?id=921.

Keep in mind that much spread of OW is by root grafts, so wound dressings won't help there.

Until the end of September, I was Jenny's boss, and am now proud to be another Forest Service scientist!

[/ QUOTE ]

Kevin,

I understand your inclination as expressed in your post's first line, but I also feel that there has been a general muddying of the issues over the many years I've been trying to learn about trees. In 1988, I was pretty sure not to stand under trees during a lightning storm, but that was the practical extent of my scientific mutterings.

After being introduced to Alex, I took the world of learning very seriously and was continuously disappointed by the myths and contradictions that kept popping up in print and lectures. We had the equivalent of political talking points that kept being repeated until they had the assurance and familiarity of facts. Some things have been cleaned out and discarded, and other factoids have hung on with Velcro.

If we recognize that the majority of oak wilt infections come from root grafts, there is still a significant probability of additional infections based on fresh surface wounds. Seems to me, that the do no harm rule could comfortably be used by arborists in any of their cuts or woundings.

The problem may not be keeping the pathogens out by sealing or closing over the wound, but by introducing the spores internally as the teeth cut through the bark. Besides the calendar cycles, we don't really have a way of knowing the saturation level of spores except to find trees with the symptoms of nearby oak wilt.

To me, a vector is a vector; beetles or saw teeth both introduce spores beneath the surface protection of the bark. I think that prudence with some caveats could be very important in reducing the statistics for open wound infections. I'd want to consider low toxic paints, gels, or sealants--and minimize damage to the cambium that has the function of new wood and bark.


Bob local wits

PS: BTW, how many people believe that disinfecting tools has a meaningful consequence? Lysol? Against nature's evolved protections to keep spores viable for decades?
 
"Seems to me, that the do no harm rule could comfortably be used by arborists in any of their cuts or woundings."

this seems reasonable. do possible good, as opposed to nothing.

my bias is against heartrot from big wounds. how can we sit idly by and watch?
 
You must log in or register to reply here.

New threads New posts

Back
Top Bottom