Virus or bad culture

[Zoey]

Hope pics get through. Thanks to all who gave advice.

[Eyebabe]

Looks like a fungal or bacterial infection to me.
Also check the underside of the leaves for scale.
Doubt it's a virus.

[Alyons]

Def not a virus. Looks like sunburn, or maybe a fungal or bacterial infection.

[Zoey]

No scale apparent. What is a good fungicide to use? Sure appreciate the help. Zoey

[Zoey]

Thanks for the help. Maybe dealing with a fungus. Should these plants be kept by themselves? Zoey

[silken]

I would move those plants away from any others ASAP. I see several comments that suggest it isn't a virus. But I have had one after another of my Phals go from healthy looking plants to that and worse. Especially like the 1st picture. It started with one plant from a grocery store. Beautiful blooms but then the leaves started looking like that. Opinions at our orchid society suggested a drastic temp. change-which hadn't happened while I had it. So I left it as is. Then another one on the same table started to turn. Stupidly I ended up with 5 residing on the same table along with some other orchids. Nothing else but the Phals seem to be affected. But just last week, I decided I will toss them, pots and all, sanitize the whole area and wait a good long time before any more Phals go there. I have other Phals that are in other areas and none have a problem. One of my fav's that I had for 2 years and growing in another area somehow got set on that table with the others and it too is going in the garbage as soon as I enjoy the blooms for a few days. It had been a gorgeous plant till I moved it. Just to be safe I would isolate them and then wait and see. My problem has been going on for over a year so it is time to act. Every time a new leaf grew, they would be clear and beautiful and I would think, it was 'cured'. But by the time it was mature it was looking like in your photo only it spreads thru the entire leaf with time.

[Ray]

It looks to me like mesophyll collapse, which can occur simply upon watering with cold water. The decomposing tissue can harbor bacterial or fungal infections, so keep the plant itself dry, and keep an eye on it.

AOS | Mesophyll Cell Collpase

[BikerDoc5968]

Leave it to Ray to have the answer. He is just too fast for me! I have seen this happen to my phals when I use cold water, especially in the winter. And as Ray said this is the perfect setup for infection... just like us humans when the integrity of the skin is compromised G-d knows what can happen.

[silken]

I have attached some photos of my remaining 3 Phals that I am throwing out today. My favourite one is in bloom and has 3 branches of buds so it kills me to toss it, but I have decided, its never going to recover. The other two have well developed bloom spikes with buds that will open soon. Ironically these plants are robust growers that bloom reliably and their pots are full of healthy roots. Even the flowers look fine and un-marked, but every Phal that has come near them ends up the same. To me the symptoms look the same as the ones Zoey posted. It is not caused from cold water. I use room temp water and have tried two different sources. They were getting tap water, but have since switched to rain water last summer. Also, all my other Phals get watered at the same time and from the same water source and it only affects the Phals on the one table soon after they have moved there. They get the same temps and conditions as any other Phals.

I hope Zoey doesn't have this, but still think she should isolate them ASAP or throw them out as I am doing today.

A couple of the leaves in the photos are rather dusty but I didn't want to wipe them and risk spreading any organisms in the air or elsewhere since they are headed for the garbage anyways. I also added a photo of the one that has some flowers open. A mini phal called Abundance, which always has blooms in great abundance! I will try and replace that one. I've consoled myself by ordering more orchids to be picked up at a show in Edmonton that I am going to in a few weeks