Fungal rot on a Bulbophyllum treschii?

[Jason Barrette]

Judging by your pictures, the roots look to me like they went through a severe dry spell. I’m not familiar with your species but the pbulbs look somewhat shriveled for a Bulb as well. I would clean (peel) the dead bract covering the pbulbs that have the rot on them and make sure that it’s in a location with decent air flow. If the pbulbs that have the fungus are hard, then there’s life in them. Any of my Bulbophylums that aren’t in decent air flow get that fungus on the dead bract because the potting mix is usually damp. I would also cut off any of the roots that are desiccated before repotting and clean them with your favorite antifungal spray. I use hydrogen peroxide.