Extremely concerning spots on Coelogyne

[estación seca]

To pile on, are these old leaves? Older, dying leaves often develop all sorts of brown spots before they go. The plant decides the leaf is to be jettisoned, and the vascular channels at the stem close. The leaf doesn't get normal water circulation, fungus can attack dying tissue.

I have never seen ones like this, but in my growing area older thin leaves often develop large brown spots before they fall.

I don't worry about brown spots on leaves unless they are newer leaves, the spots are moist not dry, and I'm sure it's not sunburn. I have lower relative humidity than you, but my growing area varies between 40% and 80%. I am certain I have never had any fungal diseases in my collection. All the bad looking leaves were due to normal leaf death, or my sloppy cultivation techniques.

[BrassavolaStars]

Hello All,

Thank you all for the really good advice.

To go into a but more detail about the spots, they haven’t really changed much since I received the plant and they were present. They aren’t soft or wet and there isn’t really any discernible tissue collapse.

It is honestly like someone took a burnt sienna marker and drew on the underside of the leaves by making a bunch of dots in a spray pattern.

The roots are good and it has been growing new growths that don’t seem too spotted and even newer growths are coming. It also has been blooming fine. It has been stable for months so I guess I’ll just treat it with fungicide to be sure.

As an aside question, does flaming tools disinfect them from viruses without using bleach or alcohol? If I hold scissors under a butane torch for 15 seconds (heating both sides and every inch), would that deactivate any viruses so I can use it directly on another’s plant?

I’ve been doing this instead of wiping with bleach or anything. Should I have been washing them in addition to scissor flambé?

[Roberta]

Propane torch flame definitely will disinfect cutting tools. Nothing organic will survive that heat even for a few seconds. I think that it is much more certain than any chemical disinfectant (and a whole lot faster... meaning that you are more likely to do it consistently) I know someone who uses a veterinary product containing bleach, it's really strong - if mixed fresh, heat does damage cutters. I just use inexpensive clippers from Home Depot, the blades survive about 6 months with all the flaming (can revive for a few sharpenings), then I discard and buy another... about $10, so investment is low.

[estación seca]

I have read in the past people find buying single-edge razor blades to be the least expensive alternative.

[Roberta]

Originally Posted by estación seca

I have read in the past people find buying single-edge razor blades to be the least expensive alternative.

Those certainly work, and are the most no-fooling clean. For sampling for virus testing that's all I ever use. However, I'd recommend them only for small/easy cuts... using on a tough Cattleya or Cymbidium rhizome carries a risk of sliced fingers if they slip (if they can make the cut at all) . (For larger Cyms, I also sometimes use a cheap serrated-edge steak knife that I can flame... when really stern measures are required)

[estación seca]

I still have a scar on my left index finger from cutting aquarium air tubing with a single-edged razor blade at age 10.