What has killed branches on this generic Acer Palmatum

Discussion in 'Maples' started by MarkVIIIMarc, May 29, 2013.

  1. MarkVIIIMarc

    MarkVIIIMarc Active Member

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    This is a branch off about a ten year old generic acer palmatum I planted out in the yard. Generally the tree looks healthy as a multi trunk specimen even doing well through last year's record drought and heat. This year there are some bare twigs I blamed on a series of cold snaps after it leafed out.

    Now this year besides the usual pruning so I can mow around it, I have removed two branches on which all the leaves shriveled up and died. They were on different stems and this is the larger of the two. Maybe 4 foot or a bit over a meter long. The first was smaller and I removed it about a month ago.

    About 300 feet away I have a "fire" something or other coral bark cultivar which has never over wintered well. Perhaps the same month ago it lost it's .25 meter leader to a similar problem and otherwise looks healthy.

    This spring has been pretty wet but not to the point of being a record setting year. There were also them dips into the lower thirties so I blame the small bare stems on that.

    If this were the only branch I would say something got into the tree from that lowest pruning cut. (there was another six inches below that removed back to the branch collar as I did not want to remove it all at once.) However the other branch was one I did not prune near and I did not prune that small other tree.

    One other thing I did not do is wait to see if the shriveled death spread or if the branches releafed.

    Thanks for any tips.
     

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  2. maplesandpaws

    maplesandpaws Active Member

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    Firstly, after cutting off the affected branches, did you sterilize you cutting tool(s)? If not, do so immediately so you don't potentially infect any of your other trees - and make sure to sterilize in between cuts on the affected tree(s) to prevent the spread of the disease from one part of the plant to another. I am definitely not an expert, but this looks very much like what I've been fighting the past 2-3 weeks with many of my small maples (mostly 5g and under in size, all in pots). I initially thought it was pseudomonas, but after feedback from other forum members, as well as a local nursery that is more knowledgeable when it comes to Japanese maples, I am now fairly certain it is fungal in nature (probably phytopthora) - the way you have the dark spots on the branch, right where another branch intersects it, and you have healthy tissue on either side is exactly how all my affected trees started out. Unfortunately, half have died already, and I'm not too sure the others will make it. :( The good thing is your tree is larger and in the ground, which always helps, and if your tree is otherwise healthy and not stressed, it may lose a branch or two, but should be strong enough to recover. I'm guessing an anti-fungal treatment, systemic probably, either sprayed topically and/or applied as a drench would probably be the best thing to do at this point. But, as mentioned, I'm most certainly not an expert so hopefully those others on the forum who are more knowledgeable and experienced than I will give their input. Another recommendation might be to take the affected branch(es) to a local nursery or your local extension office's Master Gardener for better diagnosis - seeing in person is always better than pictures on a screen.

    Hope this helps! :)
     
  3. MarkVIIIMarc

    MarkVIIIMarc Active Member

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    Thanks for the tip. It makes sense and I will go to the store later and do some shopping.

    FWIW, I used hydrogen peroxide this time for the sanitation. In the past I have used carb cleaner and baby wipes, whatever was handy.
     
  4. Schattenfreude

    Schattenfreude Active Member

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    Mark,

    Could you (or a neighbor) have used an herbicide recently and accidentally hit the tree with the overspray? I've never seen such die-back on a branch of that size before.

    Kevin in KC
     
  5. MarkVIIIMarc

    MarkVIIIMarc Active Member

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    A fair question.

    I have used Round-up once this year on that very same driveway I walked over to for the pictures. My beighbor is fifty feet away and in no form uses herbicide. The street might only be twenty or twenty five feet from it.

    Man, I am pretty careful with the stuff and those are interior branches on the tree but I suppose anything is possible. Just seems unlikely since that tree and one 300 feet away had similar branch death.
    Is that kind of random delayed death possible witg round up?
     
  6. JT1

    JT1 Contributor

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    I think the dried wilted leaves are due to the black tissue clogs the vascular system of that branch. When things were cooler, the leaves could keep up with transpiration (let’s just say the black was around 50% of the branch). Now the sun is more intense and the temperature is up, so the tree could not supply adequate moisture to the leaves with a 50% blockage, so everything down stream of the blockage dries up. This is the time of year that it happens when dealing with this problem. The key is to hope that it does not get into the main trunk or at the base. Then you lose the whole canopy almost overnight.

    I only lost one maple in all my years of collecting and it was to this problem, Pseudomonas syringae . It was in the trunk above the graft. The tree collapsed as we got into late May and early June.

    It's my understanding this infection can be with the tree in the beginning and it takes being stressed to bring it out. Sometimes with grafting it can be in the under stock and then spreads to the scion wood. If the tree stays healthy and relatively unstressed, you will never know it's there. But add stress into the equation and you end up with problems such as yours.

    Maybe it was due to the very harsh and dry growing season last year, then add a very wet spring this year, and you have a formula to bring out problems such as this, but I am only guessing since I don’t know the history of the tree.

    I am not an expert in diagnosing problems, so I may have miss-diagnosed your problem (So far I managed to keep all my maples healthy and happy, so I am not very familiar with losing them). But your problem is strikingly similar to my loss to Pseudomonas syringae . Even the color of the wood where you cut it is strikingly similar. I kind of performed an autopsy on my tree because I wanted to learn as much as I could from the loss.

    Some tips or considerations
    -Don’t use nitrogen. The use of nitrogen can promote outbreaks.
    -Don’t prune in winter. It’s my opinion that winter pruning leads to black tips and bacterial infections. I switched to pruning late spring and never have problems with black tips anymore.
    -Don't prune wet branches. Rain or water helps spread bacteria into the cut.
    -Sanitize pruning shears. It may be a bit much, but sanitize between cuts on a tree with a known infection. Sanitize between pruning two different trees to prevent cross contamination.
    -Use 0-10-10 in late summer and early fall to help harden off tender new growth so that it better stands up to winter. This also promotes healthy root growth, healthy bud formation, and I have noticed it helps wound wood form quicker over pruning cuts.
    -Spray lime sulfur in late winter to prevent bugs and infection. Only use copper spray as needed, because bacteria can build up a tolerance to regular applications.
    -A more controversial suggestion is to seal larger pruning cuts. I use wood glue and aluminum foil to cover the surface area of the cut. It helps limit moisture loss and allows for the wound wood to form more quickly. But I am sure it will be the opinion of many that I am nuts for suggesting it. (I have heard it all before about a proper cut, nature does not seal, someone with a PHD says not to, etc.… But I have noticed good results since I started doing it 5 years ago. The foil is a bit much for the average person, but the wood glue alone works well too)
    -Then the obvious is to limit stress by regular watering during the hottest part of the summer and protect the tree from frost (both early and late season frost. Protection from both is equally important when dealing with bacterial infection or for preventing an outbreak).
     
    Last edited: Jun 2, 2013
  7. maf

    maf Well-Known Member Maple Society

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  8. MarkVIIIMarc

    MarkVIIIMarc Active Member

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    Well, whatever it is just claimed all the leaves off a third of the remaining tree. Pretty impressive, this is a trunk as tall as I am dead in the last couple days.

    From here, where do I go?

    I am mildly interested in an official diagnosis. What do I do?

    When do I declare the tree dead? Or is that dependant on the diagnosis I suppose. Being June now I have at least three months before prime planting season.

    Thanks for the links btw. At the very least I will replace with a non suceptible species assuming the ol boy doesn't make it.
     
  9. maplesandpaws

    maplesandpaws Active Member

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    You should be able to take a portion of the tree to your local extension office; one of the Master Gardeners there may be able to diagnose it, but if not, they can send off the sample you bring in to the horticulture department of one of your universities, etc, for testing. You may want to call ahead to find out what sort (and size) of sample they would like to have.
     
  10. 17 Maples

    17 Maples Active Member

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    curious Mark have you had chance to dig down a couple inches at the trunk line/below into the ground just to check basal roots for scaring and possible decay ?
     
  11. MarkVIIIMarc

    MarkVIIIMarc Active Member

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    Ok... I went out and did some digging. Just an inch or so from the soil I found the first roots. Small fellas and a bit more dry than I assumed. It has been a wet year! I expected to find more large roots. Although I like to think I did not plant my foot tall Arbor Day Foundation special too deep...

    I also took pictures of new growth, a green trunck with live leaves and two of the newly dead and discolored trunk.

    Btw, this board is great. Good advice and I was able to attach all this from my cell.
     
  12. MarkVIIIMarc

    MarkVIIIMarc Active Member

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    Oh, and I found contact information for my extension office btw. I will either email later or call tomorrow.
     

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