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.