aconitifolium bud desease

Discussion in 'Maples' started by opusoculi, Mar 5, 2014.

  1. opusoculi

    opusoculi Well-Known Member

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    This is for Acer japonicum aconitifolium in container.

    It began in november, a few buds turning grey; this is recurrent every year in november/december.
    In december 2013 i decide to pulverize some cooper (oxychlorure as for fruit trees) . Then i protect it from hivernal rain , as i am used to do for all my pots and containers.
    Since then the desease don't progress over others buds. A greater part of stems are now starting to rise.

    Could you help me to find the name of this cryptogam. i always read with pleasure yours excellents advices .

    3 photos as they are the 5/march
     

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  2. Schattenfreude

    Schattenfreude Active Member

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    Could it not be birds eating your buds? I always seem to have buds that look like this after a long winter. I just assumed it was a bird or squirrel eating the buds, since they are so plump (and delicious-looking). Do the secondary buds eventually develop and give you some new leaves?

    I hope someone else can chime in here... and educate both of us!

    Kevin in KC
     
  3. emery

    emery Renowned Contributor Maple Society 10 Years

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    I see this often, also. It seems to be specific to the big buds on japonicum types, always with terminal buds. I looked and there are some of these on a large Vitifolium as well as an Aconitifolium, both in the ground.

    My sense has been that in a warm, wet fall some buds start to swell without properly becoming dormant (or break dormancy early). This allows bacteria, like pseudomonas, to enter the bud and kill the tip. In your picture 2 you can see some blackening, which supports this theory.

    I always spray with copper a couple of times during fall, winter. I don't know if this is why this issue has never been serious for me.

    HTH,

    -E

    P.S. un peu de sec enfin, eh? Ca nous fait du bien... ;)
     
  4. JT1

    JT1 Contributor

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    My aconitifolium had the same problem as two isolated incidences.

    The first was from our dryer vent, blowing warm air on a branch over fall and winter. The warmth caused the buds to extend further than the rest of the buds on the branch that were away from the heat. As a result, the buds failed over winter and it died back to the next pair of buds away from the heat. Once pruned back to the healthy buds, the tree continued to be healthy for the rest of the growing season. (branches were pruned and redirected away from the dryer vent in late Spring and the problem never re-occurred).

    The second time was with the same tree but on the other side and several seasons later. The tree is on the SW corner of my house, so over winter it gets morning sun and afternoon shade. Well one branch grew past the corner of the house into all day sun. The sun warmed the buds at the tip and I noted they were extending faster than the rest of the buds. Failure resulted because of a combination of factors. First, branches that are exposed to afternoon sun cool rapidly after sunset resulting in damage. The other factor, the branch was no longer protected from winter winds like the rest of the tree.

    For me, I fixed it through pruning and redirecting branches away from a heat source over winter. This kept the buds from extending past their winter hardening for that time of year. The other thing I noticed is that Acer japonicum is better at isolating damage and stopping the spread of infection, unlike many Acer palmatum. The infection tends to stop at the first set of healthy buds and the infected and damaged area can be pruned away.

    For you, I recommend taking a look at the buds that show this damage. Are they close to an artificial heat source or are they being exposed to afternoon sun, warming the tips more than the rest of the tree? If so, then try to correct the issue and see if the problem returns next winter. Correcting the issue can be easily done if the tree is container grown, just move it to a protected location and out of afternoon sun over winter. If the tree is in the ground, then investigate the cause and try to redirect the branch or prune back if needed.

    I have also seen bud tip damage from frost. The tips get damaged, but if its not a hard frost, the inner buds stay somewhat protected and free from heavy damage or failure.


    Birds eating buds are no laughing matter either. I am not sure that is the case here, but sparrows can be very destructive in late winter and early spring. They tend to favor Acer palmatum and hit Acer shirasawanum less severely, unless the tree is young, then all bets are off. They tend to leave my japonicum alone, but maybe its because they have so many other choices of palmatum, they never get around to japonicum.

    The tree usually will rebound, with secondary buds and it will fill in by late spring. But, some varieties don't recover well. They destroyed my very old filigree last Spring, I lost 65% of the canopy by late Spring. Also, when they do hit Acer shirasawanum branches hard, they tend to fail too. My Areum took a big hit last year too, loosing a hand full of branches, making it appear less full, exposing the wall behind it for the first time ever (you could see through the tree in areas due to the loss of branches).
     
  5. opusoculi

    opusoculi Well-Known Member

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    Many thanks for yours lighted answers.
    I don't think it is birds.
    "some buds start to swell without properly becoming dormant". Yes, here is the light !
    And then bacteria enter the bud...
    I remember end of november 13, buds where too big, so i bring the pot and put it in north shade. Begining december a little number of buds where grey, wherefrom i pulverized some cooper.
    This 6 years tree is container grown (slowly). Each year, after fall, this desease returns in december. Consequently it is now a multi-redirected aconitifolium; rebound after rebound it looks as a missed bonsaï ... But i am learning thomething with you !

    Happily, it is the only one with that problem <=> "it seems to bee a specific problem to big buds on japonicum types".
    I have to be more carefull next year in novembre.

    @JT1 . Yours descriptons are sharp-pointed , be sure i appreciate . yours words are drawings .



    Ah oui, enfin sec, très beau temps pour finir les rempotages dans la bonne humeur.
    Mes Erables
    http://jalbum.net/a/1438483
     

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  6. JT1

    JT1 Contributor

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    Thank you very much for your kind words :-)
     

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