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Black streak up bulb and then progressive dark spot on leaf of Cattleya.

Discussion in 'Issues, Disease and Pests' started by Tropic, Jul 28, 2013.

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  1. Tropic

    Tropic New Member

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    The dark streak began on the lower part of the bulb and gradually spread upwards through the new bulb to the leaf. There it continued to grow into an awful dark spot. What is it? Bacteria or fungus. Any treatment advise?
    Cattleya infection 2.JPG
     
  2. ZWUM

    ZWUM Bulbophiliac Staff Member

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    Yikes! Not sure what that is. Is the leaf or pbulb mushy or wet? I know fusarium wilt travels trough a plant quickly and you can see evidence of it in the rhizome. I'm really not sure if fusarium could manifest itself like what's in your photo. Have you tried any systemic fungicide/bactericide?
     
  3. Tropic

    Tropic New Member

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    I have not really tried anything special more than spraying with Physan and eventually decided to remove the bulb and sterilize areas where there could be some remaining 'infection'
    Maybe something systemic would have been more effective, but it all happened very quickly.
     
  4. Marni

    Marni Well-Known Member Staff Member Supporting Member

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    If the rhizome where you cut it was white inside it should be good. If you have some black in the rhizome I am told to cut back to a spot where there is no black or it will spread.
     
  5. Ray

    Ray Orchid Iconoclast Supporting Member

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    I agree with Marni. That is a systemic infection (which is why Physan won't touch it - it's a topical treatment only), so you need to remove all traces of the infected parts from the plant.

    Cattleyas are pretty sturdy, so a post-treatment with Phyton 27 might help.