Monday, March 8, 2010

Tawain Orchid Virus or Microfungus??

I am completely devastated by this rampant infection threatening my entire orchid collection. So far I have many phalaenopsis plants affected as well as most of my plants from the oncidium alliance. Seems to be spreading where close contact is present as my isolated plants show no signs of this disease. I have to throw out all the plants affected or keep them isolated until it resolves or takes over the plant. Symptoms include blotchy round yellow spots on leaves, silvery white pitted sunken areas on leaves, brown sunken spots on leaves, brown spots on leaves , all spots also appear underneath (through the leaf tissue). No insect pathogens present on any of the plants (no mites, whiteflies, fungus gnats, etc..).

Here are excellent photos of the symptoms exhibited by the affected plants:

(A1)First phalaenopsis affected (advanced stage):
(A2)Close up of same plant leaf
(A3)Oncidium type plant with suspicious spots before my phals got infected:

(A4)Another infected phal, with lighter brown sunken spots as well as yellow blotches.

(A5)My favorite phal with yellow blotches and sunken dried areas.

(A6)Early stages of disease showing lighter spots gradually turning yellowish.

(A7)Close up of same plant

(A8)Oncidium type plant with suspicious blotches, mostly dark brown but some yellow

(A9)Another oncidum type plant with similar brown spots.


  1. Dude I have the same problem as you do. Phalaenopsis with white sunken splotches under the leaves, over time they are turning brown. Did you ever manage to successfully cure any of them?

  2. Have not cured any but cut away the leaves and no new spots have appeared so far. The badly affected ones have been thrown out.

  3. It’s really troublesome to find that these orchids you spent lots of time taking care of are ending up like this. You will help a lot of orchid growers to prevent further damage by letting us see these warnings. Aside from these spots and discolorations on leaves, there are a few more orchid warning signs that could tell you your plants are in trouble like spotty flowers and shoddy roots. Check if they also have these. If they also have these, they are really in big trouble.

  4. Thanks for the link and info Mary Ann, I will check it out. I have tested a few of my plants for virus and will post the results shorlty.

  5. Thanks for the pictures. Do you test for the virus at home or are you sending tissue samples away? I would be interested to hear the procedure for that. Thanks!

  6. I had the same problem, i sendet a leave ( Phal.) in a laboratory. Result : these are bacteries, it is very, very infectious !
    Antibiotics for Plants are not possible for private person.
    ( sorry my englisch, swiss.... )

    Regards Nicole

  7. So what is the conclusion on your plants?

  8. Hi, read this thread:

  9. So my orchids are looking exactly like your pictures for A4 and A5 (mostly A4). Did you ever find out if that plant was infected with a virus? I can't seem to find any other picture online that matched what my orchid looks like, except yours!

  10. Not sure what it was on the phals, but one that did survive and was put in quarantine actually looks like a normal and healthy plant now! It could in fact have been bacterial or fungal and not viral.... Look at the results of some viral tests on my other post here: