Dendrobium jenkensii fungus

[Burgos]

This Dendrobium has had this fungus ever since I bought it a month ago. I think the fungus was present in some other orchids I bought, but it hasn't reappeared. However, it seems to be quite strong in this one and it flourishes whenever I water the plant.

I tried cinnamon, but id has had no effect on the disease. I have a copper based fungicide but I'm concerned about using it on dendrobiums since they seem to be badly affected by this metal.

Here's a photo:

https://imgur.com/RA0ivhr

I repotted it as soon as it arrived home and you can see the fungus spreads right between the bulbs. This makes me think that it was infected when I bought it.

Thanks!

[WaterWitchin]

Looks like snow mold (Ptychogaster sp.) to me. Usually due to decaying medium. Even if you repotted into fresh medium, the fungus is still traveling along on the roots, etc, of the orchid.

I would get some air movement on it, treat with a fungicide appropriate for snow mold, repeat treatment once a week for a couple of weeks, and slow down on the watering. Were it mine, I'd probably cut back some of the infected pbulbs that already look three-fourths worn out anyway. There are a couple of fungicides for it when I google, but I'm not the right one to suggest which fungicide to use. Wouldn't use a copper based one.

---------- Post added at 09:50 AM ---------- Previous post was at 09:44 AM ----------

PS If you didn't treat with a fungicide prior to repotting, were it me I'd also de-pot it, use the fungicide, pitch the medium you used and start once again with fresh medium. Drench the medium as well with the fungicide.

[Burgos]

Thanks for your help. I've reduced waterings and I've placed the orchid outdoors since we're getting some warm and dry days. It seems to have got better. I tried removing part of the fungus by hand. We'll see how that progresses when the new flush of growth comes out.

Thanks again!