Virus

[Lindafvb]

Hi everyone,
About 2 months ago I purchased a Paph. gardinerii. The buds opened and a new fan continues to grow. So far so good but.... today I found the bottom leaf of the old fan had turned red half way up the leaf. I bought the plant with obvious cell collapse on other leafs but I now notice that these same areas also have a red tinge. This mark grew very fast, hence why I am thinking a virus. What do you think? Hopefully the picture is attached.
Thankyou
Linda

[smartie2000]

Not a virus!
Paphs rarely get viruses (although they can) and when they get viruses I believe they do not usually show symptoms. Some just slowly die. In a survey done in europe,out of a large collection of orchids, paphs were the least infected of all genera.

[smartie2000]

Looks to me that there is some cellular collapse. How is the humidity levels of your growing area?

Is that first picture a picture of the bottom most leaf?

[justatypn]

Linda looks like Tobacco mosaic virus, it's untreatable. If it is not particularly valuable, burn it. Many diseases, particularly viruses, closely resemble other things. I recommend that you isolate any plants that are important to you and have them tested before destroying. Space plants so that they do not touch. Symptoms with this type of virus have black, red, or yellow spots or streaks on leaves. Flowers may have white or brown streaks or mosaic pattern.

[smartie2000]

Cellular collapse can turn brown with time...

I see that you have posted a thread on slippertalk, some experts can help you because i'm not a plant pathologist. I will link this thread there since you didn't load the pictures on ST.
Virus? - Slippertalk.com - Slipper Orchid Forum for Paphs, Phrags other slipper orchids

I am sure that it is not a virus, but you can get it tested if you wish.

It may just be a rot, that is curable. Maybe a fungal one

Worst case scenario would be Erwinia, but I am not certain.

I think using physan 20 wouldn't hurt

[gerneveyn]

You could take the plant to your local county extension office; they should have someone who knows about plant pathologies. For example, see this link for ocean county NJ: RCRE of Ocean County: Home Horticulture & Master Gardeners

[justatypn]

That's a great idea Sarah, the experts at the extension should know, its something we do as hobbist do not come in contact with very often. Smarties suggestion of physan is a good one...something every hobbist should keep around on their orchid tables.

[Lindafvb]

Thanks everyone. I did place the plant in isolation immediately. When I bought it back in Feb. I kept it isolated from the others. I only recently placed in with the group. The cellular collapse was there when I bought it. I know it is not pretty but also felt it would not damage the plant overall.Thanks Smartie2000 for sending the picture over. I tried several times to attach the picture but could not get it right. Appreciate your help. And yes, the 1st picture is the bottom leaf.
What does everyone think if I discard the mother plant and try to save the new fan? Treat the new fan with physan and hope it was not infected?

[Lagoon]

I don't think it looks like a virus. But you can never be sure unless you test for it. I've seen these types of leaves in my own paphs, I have removed them and nothing else has come from it.They grow and flower well.
Older paphs fans will do this as new fans arise. Treat if you think you should, treat for sure if you see it's reaching any new fans or the crown area.
Just my thinking .....

[Lindafvb]

Well here's another interesting observation about this leaf. I did remove it last night and placed it in a baggie. This morning the red area has grown. Another inch on the leaf is covered. At this rate the entire leaf will be covered by tomorrow.