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Mold on flowers

Discussion in 'Introduce Yourself' started by Arnold, Feb 11, 2024.

  1. Arnold

    Arnold New Member

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    I grow my orchids in an intermediate greenhouse and keep the humidity up between 80% and 100% which is what the plants want. However recently I noticed some of the flower inflorescences have been getting mold or rotting at the tips. I have a fan blowing all the time so they are drying off at the end of the day. I noticed this most recently on my Góngora scaphephorus, my Cattleya intermdia, and Laelia lundii. It’s frustrating to lose these little flower buds. I have also noticed some crown rot where the leaves meet the main stem on some dendrobium Any suggestions?
     
  2. Roberta

    Roberta Active Member

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    Location:
    Coastal southern California
    Welcome!
    I think that the humidity level is too high. At those humidity levels, the natural temperature drop overnight will allow for condensation, and just asking for botrytis on the flowers. While there are some orchids that like humidity like that (moderate-elevation cloud forest ones), Catts especially don't like to be that constantly wet. So especially, I'd expect problems with C intermedia and L. (C.) lundii And at those high humidity levels, air movement may move the water around but you won't get much, if any, evaporation since the air is nearly saturated.
     
    Last edited: Feb 11, 2024
  3. ryan248

    ryan248 Well-Known Member

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    Location:
    Davis, CA
    I grow at 92% humidity, but I provides lots and lots of air circulation. I never have a mold issue.
     
  4. W. Malewa

    W. Malewa Active Member

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    Location:
    Kenya
    Is very well possible with fairly high constant temperatures and airflow. Humidity percentage by itself doesn't say so much. At which temperature, or rather what is the moisture deficit?