Declining Beallara

[jcsim]

Hello,

I've been growing plants for a few years now and I've built a substantial collection of plants, primarily Cattleyas. Several years ago, I branched out and purchased a Beallara. It arrived "healthy" and rapidly declined after. It died (well, "died") about 6 months after with a single dehydrated pseudobulb. I've avoided Oncidiums since.

I was browsing plants online and found another Beallara that I absolutely loved. It arrived with two leaves on the most recent growth and the remaining two pseudobulbs were bare. All of the pseudobulbs are slightly shriveled, so that lead me to believe that there was significant root loss, as the plant arrived moist. Unpotting the plant, I removed a copious amount of tightly packed, decayed sphagnum moss. Not surprisingly, I discovered that every single root had rotted away. I trimmed off as many roots as I could and the plant has been quarantined since. I had placed the plant in a vase with a small amount of water at the bottom to supplement humidity. When I checked on the plant, which must have gotten bumped, I noticed that the small back bulb had gotten waterlogged. I decided to trim it to prevent any problems from occurring and I figured the bulb was small enough, anyways. Upon inspecting the rhizome, there was a small reddish-brown ring.

I acknowledge the Fusarium hysteria, but until a week ago, this was not my plant. I have no idea what the growing conditions were like prior to this or what it may have been exposed to. I've read plenty of articles and studies on the symptomology of Fusarium, including Sue Bottom's work. One of the leaves on the plant is currently yellowing, it has no roots, and has a reddish ring on rhizome. This plant is by no means "healthy." So far, this has followed the exact pattern of atrophy as my last Beallara. Interestly, it's in the same type of pot, the same size (three pseudobulbs), and has an identical yellow label.

While I would like to save this plant and bring it back to health, I would much rather not compromise the rest of my collection. If this is Fusarium, is there any way of completely removing the infection? "Cutting until there's no ring" isn't exactly viable in this case, as there is very little rhizome to begin with. If it is in the rhizome, it is in the pseudobulbs. I have read conflicting information regarding Fusarium being removed via systemic fungicidal soaks, such as Medallion or Thiomyl. This supposedly can "remove" the fungus, allowing the plant to resume growing healthily. I have also read information stating that once a plant is infected, it may as well be trashed as nothing can remove the infection. Could this simply be a case of bacterial root rot? Has anyone else had similar problems with Oncidium intergenerics?

Cheers!

Oh and, uh, sorry about the novella.