solid copper pear blight treatment experiment

Trying something different on pear blight.
Unwilling to spray; wrapping left-over copper screen at various branch locations to see if it can retard spread on 3rd leaf pears, as not a lot of branch to sacrifice pruning.
http://twodogsgonewild.blogspot.com/2013/07/forebearance.html

Last year's experiment of wrapping copper screen on young blighted tree's fungal cankers has apparently saved a heavily cankered Bartlett and Summer Crisp pear, while our affected Luscious pear and a Rainier cherry (both challenges to our zone) treated likewise succumbed to several uncharacteristic -30° days over the winter. An un-cankered Black Tartarian cherry also croaked from the cold; unaffected North Star and Montmorency are doing fine without the wraps.

I have recently applied the wraps to a blighted Compass Cherry plum on the lingering cankers, as well as a Butternut (white walnut Juglans cinerea) that has struggled since we reintroduced it to the north woods of Wisconsin in 2011. I must say that it seems to be succeeding, particularly with the Juglans, which was on the ropes.

As the dose is unmeasured and continuing, any advice on if and when the copper need be removed would be most appreciated.

for photo of Butternut with copper wrap over canker:
http://twodogsgonewild.blogspot.com/...or-dogdom.html
fruit tree wraps also depicted in previous posts there
For description of Butternut malady:
http://www.na.fs.fed.us/spfo/pubs/ho...but/ht_but.htm

William, I cannot see your blog due to my computers protection software.

Can you write a short explanation of this treatment and why it seems to work?

Yes, I can. Best as I recall, confronted with wide-spread blight on our fruit trees last year, I looked into spray remedies on the internet and found the prospect intimidating and possibly hazardous. After antibiotics, copper sprays seemed to be the treatment of choice commercially, so I turned to materials at hand: left over copper screen from window restorations on our old duplex. As depicted in the initial post here from 2013, I cut small strips the size of the many cankers on the young fruit trees, and simply wrapped them as best I could, as well as a larger, 6" band for the base, as I had gathered in my reading that the fungus travels up and down easily, and can splash up from the soil in the rain. This Spring, two of the infected and treated pears are completely canker-free, and I have removed many of the branch wraps; i have left the base wraps on in case the blight remains present in the soil, but wonder when the copper effect might turn from beneficial to harmful.

When I visited the Butternut for the first time this year after the snow melted, the large ugly canker at the base that had grown ever-larger since appearing shortly after planting, was filled with an alarming black material, which corresponded with the description of the blight that eradicated Butternut from Wisconsin forests as found on the USDA site cited in my last post. With the seeming success of the copper screening on the fruit trees in the orchard near the house, it occurred to me to try it on the apparently doomed Butternut. I wrapped the base and two branch cankers at the beginning of June, and when I took this photo a few days ago, the black gook in the canker at the base was diminished, and the opening seemed smaller. I will monitor this and report further developments as they occur.

As to why any of this is working, you'll have to ask someone with a more specialized knowledge. I might be a lousy scientist, but I seem to be a lucky orchardist. Better lucky than good, my Dad always said.
Too bad you can't see the place. We've been at it three years now and it's coming around.

I just clicked on both the links that I put into my earlier post and neither are operative from within this forum. Yet I assure you that my blog exists, and the Forest Service page that I found by googling Butternut cankers is alive and well in my history. Apparently the link feature provided here is unreliable when you just copy and paste a url into your post. Sorry for the presumption.

William Trachte wrote:
As to why any of this is working, you'll have to ask someone with a more specialized knowledge. I might be a lousy scientist, but I seem to be a lucky orchardist. Better lucky than good, my Dad always said.
Too bad you can't see the place. We've been at it three years now and it's coming around.

Don't sell yourself short, it looks like good science to me.

As for the explanation, it has long been known that copper salts are anti-fungal. Bordeaux mixture is a mixture of lime and copper sulfate and is used to treat pear blight. Having pieces of copper in the tree allows (acid) rain to move copper ions off the metal and onto anywhere else that the rain can splash. Copper is very slow to dissolve in acid, hydrochloric acid won't touch it, and sulfuric and acetic acid barely corrode it. Nitric acid will chew through copper very quickly, but the only time that is present in the environment is from the electrical discharge in a thunderstorm. If you think the copper is losing its effectiveness, you can freshen up the surface with a little vinegar if need be.

Thanks for the insight, John. I was more worried about too much copper than it wearing off. I do so hope that the treatment continues to prove efficacious on that Butternut, but it makes me wonder how the entire species could die off around here without someone thinking of copper to stop it. On that Forest Service site, they made it sound like you should call them right away if you found one still alive! And thanks to you, too, Miles: my very first apple!

solid copper blight treatment update
After two years with copper screen wrap on cankers at outer points on each branch and on the large black tear in the bark at the base of the bole, Butternut A has seemingly recovered, and resumed normal growth.
I had enough confidence to introduce a second sapling, similarly wrapped as a preventive, about a hundred yards away across the poor fen at the tip the next finger of high ground in the muskeg.
Two pears, Bartlett and Summer Crisp, wrapped with copper screen on many of the cankers and base of the bole, leafed out and flowered again, but we'll see if they produce fruitlets, as last year they remained unpollinated, or sterile. Possibly the loss of the third variety, Luscious, resulted in a lack of cross pollinator needed for fruit.

That's an interesting experiment, but are you sure about the composition of the screen you are using? After two years out in the elements I would expect the copper wire to be a fairly deep brown with a bit of Statue of Liberty green mixed in there. In your pictures, the mesh looks like it has been rather unaffected by the elements which would lead me to believe that there is a protective coating and the amount of exposed copper could be quite minimal.

Trust me. John, the screens are now just as you described. The shiny ones you see in first pictures are dated 2014, when they were new. At any rate, it seems to be working, and I see no downside yet.

Well William, you haven't updated this is quite a while but I thought you might like confirmation of your trial method.

The copper wires are releasing small quantities of copper ions that, when they fall on the canker create the antibiotic effects.
If you want to increase the speed of cure, it is pretty simple to do, just spray some water at the tree through the copper screen. (that is solid copper wire screen I am pretty sure, I have a roll of that stuff myself).
If you really want to speed it up you would need to make up a purified sea salt solution (I'd go with 1 TBS per gallon of water in a pressurized sprayer) which will create some copper salts that will land on the canker and that will speed up the cure.
Or, just make sure the copper mesh is in tight contact with the canker area so rain water (which contains some ionized molecules naturally) washes over both.

Redhawk

Bryant RedHawk wrote:Well William, you haven't updated this is quite a while but I thought you might like confirmation of your trial method.
Redhawk

Thanks. I haven't had the urge for exposition in some time (my blog is virtually derelict), and you have returned me to my sense of duty. We still have a foot of snow on the ground, so we remain mired in maple season here.
Aside from some pretty scraggly-looking bark on a few branches, the two remaining pears have resumed vegetative growth and have just been pruned with the apples and cherries for this year. My wife Jill, the resident arborist, had to be restrained from radical surgery on the Summer Crisp pear, as the "one-third" rule came into play. The Bartlett has set a few fruit, and the spurs are beginning to multiply; the Sumer Crisp has set none, and is visually the more damaged. I need to refurbish the wraps on this one after the pruning. Last year we dropped two apricots nearby, and they will be watched for signs of trouble.



The Butternut tree that I'm pretty proud of is ready to get more altitude this year, and I should probably put some new wraps on the upper branches before they're out of reach. The bands come apart easily and fall off as they expand.