Avocado suddenly ill - dropping leaves on top and brown spots

Discussion in 'HortForum' started by bikemandan, Sep 8, 2010.

  1. bikemandan

    bikemandan Member

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    Location:
    San Francisco Bay Area
    Local Time:
    10:25 PM
    My poor avocado tree has fallen ill. We have had a very mild summer with lots of fog and moisture in the air with cool 50-65 degree weather. Then suddenly there was a two day heat wave, one day being 100F. Sometime after the heat, I noticed the top of my avocado tree defoliating and the remaining leaves yellowing. Then I noticed that most of the leaves had brown rusty looking spots. Pictures below of the tree and leaves:

    http://bikemandan.com/stuff/DSC_0550.JPG
    http://bikemandan.com/stuff/DSC_0547.JPG
    http://bikemandan.com/stuff/DSC_0548.JPG
    http://bikemandan.com/stuff/DSC_0549.JPG



    The tree flowered early this spring but most of the flowers turned brown with no fruit. The few fruit that started to develop dropped off.
    I think the brown spots are fungus so I sprayed the whole tree with neem oil. Don't know what more I shuold do though. Should I cut off the branches on the top that are now nearly leafless?

    Any help is very appreciated!!
     
  2. HortLine

    HortLine Active Member 10 Years

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    Location:
    Vancouver, BC
    Local Time:
    10:25 PM
    Your avocado, suddenly ill, seems to fit with a typical problem that others are experiencing in your locale. You will see on this forum and on the web two culprits that may cause small brown dead spots on the leaf blade and along the veining. So this could either be Lace bug or Persea mite. The problem hasn't been seen frequently until this year. This will get you started; your pictures certainly did help to describe the problem. Others may want to see them as well. Good luck.
     
  3. bikemandan

    bikemandan Member

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    Location:
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    Local Time:
    10:25 PM
    It is definitely the persea mite! Thank you! There is a silvery sheen to spots on the back of the leaves that is apparently their webbing


    Any tips on what to do? Continue spraying neem oil? Find some place to buy beneficial mites and lacewings?
     

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