CymMv ORSV Advice
 

I've been dealing with a minor slow moving tragedy in my greenhouse for a couple months. About 65% of my phalaenopsis are showing significant signs of CymMV ORSV infection (leaf pitting). All of my s/h phals except one show the disease and it first emerged on a night that was quite cold. 80% organically potted phals and all other species had not been affected. Here is a pic of them in bloom and pitted:
https://lh3.googleusercontent.com/qf...=w1124-h843-no

This morning I discovered a couple catts with spots and learned it could be passed to my cats. I was planning a wait and see approach while changing any habit or setup that would favor disease spread. My cost/benefit calculation in keeping them is less clear now that I know they pose a potential threat to my valueable cattleya and catasetum collections. What would you guys do in my shoes? Would you throw out these blooming phals? What about the pictured catts? I grow indoors, what is the likelihood of spread if I keep ones suspected of being infected on the other side of the room?

https://lh3.googleusercontent.com/d3...U=w633-h843-no
https://lh3.googleusercontent.com/nZ...Q=w633-h843-no

---------- Post added at 09:45 AM ---------- Previous post was at 09:40 AM ----------

Almost all the affected phals are grocery store rescues that I bought for a couple bucks or got for free when they were done blooming. Fortunately most of those went into S/h and I left the higher end phals in organic media. I think the stress of the s/h conversion plus the s/h roots being more susceptible to cold nights made them more vulnerable to disease, its nothing inherently wrong with s/h. Just not good for my cooler nights in the winter. I am sure s/h would be fantastic for phals in a hot environment.

Are you certain it is a virus and not nearly invisible mites? Someone in my orchid society had Phal leaves pitting and they discovered it was a type of mite that one can only see under a magnifying glass (it did not make webs, either). They solved the problem by treating all their orchids with something and they keep treating them to make certain that it doesn't return. I cannot remember exactly what he does. Maybe you could ask on the Greater Akron Orchid Society Facebook page if you think mites are a possibility.

(neem oil, horticultural oil, and whatever Ray always recommends for mites would probably all be good options for treatment. The guy in our orchid society might use the horticultural oil and also spray with Listerine?).

If it is definitely a virus, you will need to find how the virus is spreading (Plant viruses spread through sap and open wounds and not by air).

Thanks for the guidance. I actually implemented a NEEM routine as part of my plan and I am scheduled to spray today. I implemented NEEM because I suspect mites are the vector spreading the virus, it would be better if they were just chewing on my plants. I also bought a magnifying glass at the time that I keep in my greenhouse and use routinely. I haven't seen any mites on the phals though, I will up my inspections.

I can't see your photos unfortunately, but I feel your pain... I also have some mysterious disease on my Phals causing pitting. I had 5-6 plants tested for about a dozen different viruses known to affect orchids (including CymMV and ORSV), and checked for mites under a binocular microscope, with everything turning up negative. Some people have suggested it might be the so-called 'micro fungus'.

Thank you for the solidarity.

I don't think I will go down the testing route knowing this. Did you happen to test for Phalaenopsis chlorotic spot virus (PhCSV)? That is another possibility here. The spots start out as yellow spots and then over time become pitted and brown. I have attached my photos, guess I need a new photo host. Do your phals look like these?

I don't see anything that is definitely a virus in these pictures. I think that if you want to rule out a virus issue, you would need to have the orchids tested (Critter Creek Lab).

For possible fungus, you could alternate your treatments with Listerine (the original flavor). I know that at least one of our Orchid Society members regularly treats all his orchids with Listerine to prevent fungus issues.

Here is a useful website that I hope will help you:

https://www.staugorchidsociety.org/P...ySueBottom.pdf

Here is Critter Creek lab's website:

Critter Creek Laboratory – Orchid Testing Lab

Good luck!

The support and information is much appreciated!!

Awhile back I had two phals with pitted leaves. I asked the Board members and was told it was ____"cell collapse," probably caused by cold water. It didn't seem plausable me. Those patches didn't spread but I did cut off a leaf and dust w cinnamon. Today I noticed the foliage had yellow spots starting on several leaves. I pitched it. I've had it for years but it was a noid. However, it did have a new leaf (clean) new roots and was throwing two additional spikes. They were not touching, nor did they share water. I don't have an answer but, I feel your pain and frustration.

I get something similar on the orchids I have outside. It usually hits under cool moist conditions. I’ve always assumed it’s fungal: if I bring them inside where it’s warmer, humidity is low, and the leaves stay dry, there’s no spread and new growth is unaffected.