Is this pseudobulb rotting on my Psycopsis?

[Wade Coleman]

So I recently went on a week long vacation back home and ever since I’ve come back, my poor Psycopsis has been slowly deteriorating. It started with the new growth it had been working on for about a month or two. It started to yellow and then the entire growth was to the point that I could easily pull it off. Then the leaves on the smaller pseudobulbs yellowed and died. I now have the three biggest leaves still in tact, but I noticed what looks to be rotting on the largest pseudobulb. The bulbs also aren’t plumping up no matter how frequently I water. I have NO IDEA what happened over the week I was gone. All that it had to endure was a week without water, could this really have been the root to all this? I’m not sure how to stop the degradation of my plant. Can anyone help me? Why would my plant that has been healthily growing for me for 5 months all of a sudden start rotting away?

[Ray]

Question number one: what is the condition of the root system?

I find that psychopsis prefer a fairly open medium, which sphagnum isn't.

[Roberta]

I have found, like Ray, that Psychopsis like an open medium. I thnk he has also pointed out that they hate to be repotted or otherwise have their roots disturbed. I grow mine in medium bark. I like terra cotta pots for the weight since they tend to be top-heavy once they develop spikes. I have also found that they actually LIKE to dry out a bit. So bark tends to last a very long time. The back bulbs won't plump up. But new growth should develop soon (having lost one new growth, it will do another)
Pot it up in bark (get rid of the sphag... gently, don't try to un-stick any adhering to roots) and then leave it alone. They don't grow fast, but they tend, in my experience, to be quite durable and once they get going, will just go and go.

[Wade Coleman]

So the medium it’s is in is mostly bark with a little bit of sphagnum mixed in and then a layer of sphagnum on top to try and encourage root growth. It was working for a while and the plant had new roots growing and developing, then I left and it suddenly decided to die. Now the roots have appeared to stop growing, but they don’t look dead or rotted.
As far as the rotting on the pseudobulb goes, is there any way to stop it?

[Roberta]

I think that the plant is just sucking on that old pseudobulb to give itself the energy to do new growth, since the roots aren't great. Let it shrivel... that what happens naturally. Remove the sphag on top. These do like to dry out. Grow fairly bright - more like Cattleya light, Phalaenopsis light not sufficient. They are really tough plants... thrive on abuse (and I suspect can be killed by kindness... mine have thrived on neglect) Just run water through the pot (no spritzing!) a couple of times a week, otherwise just let it be. (If it is any indication of just how tough these are, I have a couple from when I first started growing orchids 20+ years ago, they lived on a shelf in the upstairs hallway of my condo for about 9 years, and have continued to do nicely in my greenhouse... but clearly don't need that TLC. These forgave years of beginner mistakes... among the very few survivors of those early years)