copper and bacterial infections

Discussion in 'Maples' started by emery, Aug 5, 2017.

  1. emery

    emery Well-Known Member Maple Society 10 Years

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    One of the most common maple questions is what to do about black spots that appear in the late winter and early spring.
    These are usually bacterial infections in the bark, often caused by the pseudomonas vv. bacteria, which has the interesting property of lowering water temperatures just enough to cause ice nucleation on the bark surface. This causes tiny splits in the bark through which the bacteria is able to enter and cause an infection.

    When the temperature is swinging through the freezing point for days in late winter, pseudomonas infections are very common, especially with the thin barked Japanese Maples (various A. palmatum cvs and selections) and the Striped Maples of Acer section macrantha. To complicate matters the infection often appears low down the main stem, or most annoyingly along the graft union.

    The first line treatment for these infections is to spray with a copper solution or Bordeaux Mix. Copper is a bactericide and is usually quite effective against pseudomonas. (The next line of treatment in to surgically remove the infected area, but I have rarely found this necessary: either the copper works or the infection spreads so quickly that even surgery wont save the maple. Antibiotics are available for horticulture and are effective but are not available to the public. Given the very serious questions using antibiotics this way raise, this seems to me to be a good idea!)

    Here are a series of pictures of healing infections on Acer caudatifolium, Kawakami's Maple. I had planned to put a couple of these in the ground this spring, but the weather didn't cooperate and most of them had at least minor damage. I went through the usual regime, spraying every several days for 2 weeks, then bi-weekly for a while, then forgot about them. When I went to pot them on, I saw that the infection was mostly gone and they were healing. I cleaned out the wounds, which still looked pretty nasty as you see in the first picture, to look at the extent of the healing, and you can see that it is well advanced. The copper has been very effective, and many of the wounds will be completely healed by year's end.

    I don't cover or use balm on this kind of injury as the air seems to help the wound dry out and heal, (On purely mechanical injuries I find electrical- or packing tape a very effective band-aid to help bark regenerate, but that's a subject for another post.)

    -E
     

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  2. AlainK

    AlainK Active Member Forums Moderator Maple Society

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    The first time I noticed such symptoms was on trees I received from a well-known maple nursery. At first, trusting the reputation of the nursery, I wasn't too worried, but when the whole tree began to be infected (I just saved one out of three), I learned that it was a real problem. But it's ancient history now: since then, I take photos of all the plants I order, before opening the parcel, and just after. Fortunately I haven't had any further bad experience since then.

    This year, I was the symptoms again, on my... Acer caudatifolium. Since it was perfectly healthy when E. sent it to me, this tends to confirm what he's just written about the species that are more prone to catch this disease - we live about 350 km from each other and the climate is very similar (less wet here, a bit colder in the winter, and warmer in summer).

    The leaves, in April, seemed OK and I really wanted to save it.

    So I did about the same actually, except that instead of spraying the tree, I sort of "painted" it.

    acer-caudatifolium_170411b.jpg acer-caudatifolium_170513b.jpg

    Since I suspected that it was also due to a growing miwx that retained too much moisture, I removed it from its pot, put in in a larger one without disturbing the roots, and filled in the empty space with free-draining mix.

    Today, it's still painted blue, but the leaves are very healthy and the tree develops well:

    acer-caudatifolium_170807a.jpg

    The damaged bark is still on the trunk, but if it peels off, I would use cut-paste (the ones I use for bonsai) : it doesn't harden as much as other "balms" and prevents the wound from drying too fast, so healing is better. It's rather expensive, and meant for "small potted trees", but for saplings or young trees, I think it really helps.

    For those interested (I don't get any money for this, but it's the first link in English on my search engine):

    Amazon.com : Bonsai Cut Paste 6044 : Bonsai Tools : Patio, Lawn & Garden

    For those who live in France, I buy a 500 gr. box for a little less than 20€ (I have a discount (*) ), but if you type "bonsai cut paste", or "mastic bonsaï", or the equivalent in your language, you will find it where you live.

    (*): that's one advantage of being a member of a club, an association, or a ... Society.
     
  3. emery

    emery Well-Known Member Maple Society 10 Years

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    Alain, glad to see your caudatifolium is healing up, it looks like it's well on the way. When the center of the wound turns gray, as you know, the infection is dead. The caudatifoliums from this batch are quite variable in their hardiness. Perhaps 40 of the seedlings froze in the first winter, of the remaining 20 or so some laugh at the cold, others not so much. Unfortunately yours seems about as bad as any that made it through the first batch...

    I have also observed with these, and other snakebarks, that the damage is usually along the sun facing side, where the bark gets a little reddened and I guess is probably thinner, with poorer circulation. Caudatifolium seems to like sun well enough, but the young bark needs shade.

    Unfortunately almost all of my maples up for planting next year need shade, not sure what I'm going to do!

    After the freeze I had damage or lost many maples in pots. Some I was able to save: Eddisbury, Demi-sec, Pixie etc. Others died: Autumn Moon (x2), Summer Gold, lots of seedlings, etc.

    Now the problem is the drought, it is really incredible! Historic, they say. The stream is completely dry, the birches are yellow, maples are starting to turn. Hope things are better down by you.

    -E
     
  4. AlainK

    AlainK Active Member Forums Moderator Maple Society

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    Quite right I think, and I believe other species can suffer from "sunburn": the bark is then weakend and more prone to let fungus or bacteria get through. Remember this thread I started in February 2013?

    Healing bark damage

    I think it was the result of both too much sun on this side of the tree, then, "inphexion" (I'd rather call it that way because I'll never be sure of what it was). The same thing happened on a non-grafted A. p. palmatum, in the ground, exactly on the part of the bark that was facing South. I've planted shrubs before it since then.

    Just went out to take "forward travelling" pics while it's still daylight, and I didn't realize the scar was so ugly!

    Must do something about it tomorrow...

    acer-div-palm01_170807a.jpg acer-div-palm01_170807b.jpg acer-div-palm01_170807c.jpg
     
  5. maplesandpaws

    maplesandpaws Active Member

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    Good post Emery :) I had a very bad infection on my Matthew a couple of years ago, right at the graft union. As you can see from the first two pictures, it was actually oozing, it was so severe. I ended up doing surgery (third and fourth pic) to - hopefully - remove the worst of the infection. After removing the bark, I ended up painting on phyton 27 (copper bactericide) undiluted with a q-tip. Babied it that whole spring and summer, but it's doing great!
     

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  6. emery

    emery Well-Known Member Maple Society 10 Years

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    @AlainK thanks for the update, I'd forgotten about that tree. I wish you'd discovered something great with the patch-graft in the first picture! :) Yeah it doesn't look great but it's well on its way. Another couple of years I expect it will be healed over, though of course it will be many years until the trunk grows out enough to mask the damage.

    Andrea: yuck! I don't know but I wonder if the ooze is be a secondary infection on top of the pseudomonas. Hard spot to operate on too, do you have a pic of it now? Would be interested to see the progress. Did you use wound sealant on it? (Looks like a bad idea to me, but then as we all know I don't espouse the technique, although I'll allow that in different climates it may be a better idea than here in mudville.)
     
  7. maplesandpaws

    maplesandpaws Active Member

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    Emery, yeah it was a bit of a pain but as I'd never done anything even remotely close to this before, I watched while a local plant guru (back in Wichita) showed me how to properly do this should I need to in the future. The most critical part, other than not cutting too deep, was to be sure to dip the (very sharp) blade in alcohol after every single cut to avoid spreading the infection further. After removing the bark and 'painting' it with undiluted phyton, I moved it under the deck right up at the house so it wouldn't get rained on, and was extremely when watering not to let any water splash on the area. After about a week, when I was sure it was dry, I covered the wound with my bonsai cut paste and as per JT's recommendation, pressed tin foil, shiny side down, onto and slightly overlapping the wound and left it be. The foil came off at some point last year, can't remember when, and while the spot still looks rather gnarly where the infection was the worst, it's definitely healing well. I'll try to remember to get a picture of it for you tomorrow.
     

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