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Infected flasks

Discussion in 'Orchid Culture' started by gg68, Jul 10, 2013.

  1. gg68

    gg68 Angraecoid addict

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    I have some flasks, with strong seedlings but maybe not strong enought to be outflasked in good conditions, which are infected.
    Does anyone already try to cure some infections, directly in the flask??

    I have tried with Physan but it doesn't seem to work....
     
  2. Marni

    Marni Well-Known Member Staff Member Supporting Member

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    What does the contamination look like? I've certainly been testing ways to treat with more or less success.
     
  3. gg68

    gg68 Angraecoid addict

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    a few white mold and a kind of red veil....
     
  4. Marni

    Marni Well-Known Member Staff Member Supporting Member

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    Can you take a picture. Is it moving fast and does it look a bit waxy? or does it look powdery and dry?

    There are several things I've found that do help. You might want to take out a bit of the contamination and test to see how the following effects them. Take the seedlings out of the medium and soak in a 5% hydrogen peroxide. Some things foam vigorously. Make sure they all get submerged. I move them around in there and let them soak for 15 minutes. If there is a lot of discoloration/foaming I drain and replace with fresh H2O2 part way through. It is important to rinsed them several times with sterile water after. Then replate onto fresh media. If you have PPM (plant preservative material) or Fungigone that you can add to the media, that frequently helps to keep the contamination from returning, but not always. I've used alcohol for several minutes too, but usually only on things with algae/green scum. If you have PPM, you can make a 50/50 dilution and soak instead of using H2O2. I've also diluted the Fungigone and soaked.

    Don't use the PPM on lepanthes. Don't use H2O2 on nigro-hirsute dendrobiums.
     
  5. Marni

    Marni Well-Known Member Staff Member Supporting Member

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    I didn't think to ask if these were in just one spot in the flask or throughout. If it is just one spot sometimes it works to excise around the spot taking out plenty of clean media around the spot and then put 5% H2O2 in the depression that you left.
     
  6. gg68

    gg68 Angraecoid addict

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    Thank you Marni, I will try to find time to take a picture....unfortunately it is not only a spot, it seems that if all the medium is covered with something red...
    I have decided this evening to outflask the most infected flask, the only one where I had mold the seedlings started to suffer and I prefer have them in sphagnum than to find them dead when I will be back from holidays....
     
  7. aerangis

    aerangis New Member

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    UV sterilizaton works.