Urgent advice needed on decontaminating plants from disease.

[BrassavolaStars]

Hello All,

I need some urgent advice on what to do to decontaminate some plants. Three of my plants were just exposed to some sort of rot.

The rotted spot pictured exudes a dark liquid. I stupidly pushed this spot which let out air and possibly liquid near other plants and while I don’t think any got on the other plants, I want to be certain that this nasty looking disease doesn’t spread.

This spot also touched the other leaves on the same plant.

I have Physan, Alliete, Thymol, Daconil, Captan, and Immunox Spectracide. I already sprayed the physan. What should I do next to ensure that no other plants are harmed?

[Roberta]

I'll leave it to Ray to suggest the best treatment to prevent spread, he is far more knowledgeable than I am. However, for the pseudubulb with the rot, time for surgery.(If you read my posts, you will see that I don't recommend cutting very often. This is one situation where I do recommend it) That leafless back bulb, with the rotted spot on top, I would get out a single-use single-edge razor blade, and slice below the rotted area. If you see the rot extending further, slice down until you get to clean tissue. You can then dust the cut with cinnamon. Hopefully, you have caught it before it can get into the rest of the plant. When rot gets into the rhizome, the plant is history, but you may have caught it in time.

If you don't have any of those razor blades, head for your favorite home-improvement store. You can find them for modest price in the paint department, and you need to have them in your arsenal.

[Ray]

Without know the particular disease, it's hard to say what treatment to use, but I think a Physan spray on the rest of your collection is likely to have killed any pathogens on their surfaces.

I agree on Roberta's surgery recommendation, although frankly, I don't think you need to specifically go out and buy single-edge razor blades. Any sharp knife will do - I've been known to whip out my pocket knife - just don't use it on a second plant until it has been cleaned well. That's the advantage of blades - they're disposable.

[Roberta]

Another advantage of those razor blades - they are sharp, so make a clean cut. They don't work well on a tough rhizome, but on the relatively soft but firm tissue of a pseudobulb, they really are "surgical". However, Ray is right, getting the job done is more important than the tool.