Are These Spots On My Dendrobium Orchid’s Flower Buds Normal?

Question

The spots are very small and purplish. See photo below

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Answer 1

Spots can indicate a fungal, bacterial, viral, or environmental problem. It is very difficult to diagnose a disease without submitting a specimen to pathology. I've compared the spots to images of orchid diseases and it comes closest to Guignardia spots. (https://staugorchidsociety.org/culturepests-diseases.htm) For fungal issues, it is usually advised to remove the affected part and spray the rest of the plant with a fungicide. I wouldn't do that unless you can be certain what it is. Continue to monitor it, as if it is diseased, the spots will continue to grow and change and it may become more apparent what it is. Some spots appear on certain orchids for no known reason, so let's hope for that!

These publications have images and descriptions that should help.

https://staugorchidsociety.org/culturepests-diseases.htm

https://staugorchidsociety.org/PDF/GrowingDendrobiumsOrchidsinHawaii-UofHawaii.pdf

https://staugorchidsociety.org/PDF/BudBlastAndFlowerBlightingbySueBottom.pdf

https://gardens.si.edu/collections/plants/orchids/orchid-care-sheets/dendrobium/

https://www.aos.org/orchid-care/troubleshooter/leaf-problems