# Virus testing on Cattleyas



## southernbelle (Mar 14, 2021)

I've completed the testing on my Cattleyas. Still working on the Paphs, Phrags and Phals. So far, all paphs are Virus Free. Here are the stats on the Catts:
50 tested; CymMV + 9; ORSV + 4; CymMV+ & ORSV + 1; Virus Free 36. Total positive 28%
Definitely disappointing the percentage is that high, but thankful I figured this out at this point. I'm also thankful that my most valuable plants are virus free. And, I have a lot of empty bench space for new plants as all the virused plants have been destroyed! I will test each new plant, in the future, immediately upon arrival.


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## abax (Mar 14, 2021)

I feel your disappointment, but know that you'll be less stressed in the
future. Catts. seem particularly prone to virus perhaps because they're
so popular and easy to sell to an unsuspecting public. I've rarely encountered
virus problems with Phrags. I do stick with three vendors that I know I
can trust and never do eBay ever.


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## terryros (Mar 15, 2021)

Deb and I have collaborated on our virus testing. Out of 60 Cattleyas I had 6 Agdia strip positives (10%). I think I have more species and primary hybrids (the vast majority are crosses and not mericlones or divisions) than Deb and my positivity in those was only 4%.

My Paphs, Phrags, and Miltoniopsis were clean, but every single one of my Phalaenopsis were positive. They were all many years old and I could have obtained them positive as well as spread to them.

Except for a small group of special Paphs, I have a South American orchid collection now. Fortunately, I really like species and primary hybrids and look for new crosses of them rather than divisions or mericlones.


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## southernbelle (Mar 15, 2021)

terryros said:


> Deb and I have collaborated on our virus testing. Out of 60 Cattleyas I had 6 Agdia strip positives (10%). I think I have more species and primary hybrids (the vast majority are crosses and not mericlones or divisions) than Deb and my positivity in those was only 4%.
> 
> My Paphs, Phrags, and Miltoniopsis were clean, but every single one of my Phalaenopsis were positive. They were all many years old and I could have obtained them positive as well as spread to them.
> 
> Except for a small group of special Paphs, I have a South American orchid collection now. Fortunately, I really like species and primary hybrids and look for new crosses of them rather than divisions or mericlones.


Terry, I did not mention I had a pretty good thrip infestation last year among catts. From what I understand, they are pretty efficient at spreading viruses. I just wish, before I destroyed my virused plants, I would have noted if they had thrips damage or not. I do know, I have at least 3 healthy plants with scars from thrips from that time.


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## My Green Pets (Mar 15, 2021)

Great idea to go ahead and test them all. Sorry so many were infected. I have a couple plants I got last year I haven't tested...but I feel like i should now. Both were seedlings, but I realize that even seedlings can be virus positive. I've read that just by handling cigarettes or tobacco, you get tobacco mosaic virus on your hands and can infect your plants with it. Always something!


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## terryros (Mar 16, 2021)

Seedlings from new crosses have an extremely low chance of infection from most any reputable grower. It would probably harm the seedling to remove enough leaf material to do the test, so I think most serious virus hunters don’t test seedlings until they have grown larger. Mericlone seedlings would be in the same situation. I would test any larger plant from a new cross or mericloning and certainly any division from a plant as soon as I got them.

I think Deb and I learned proper disinfectant technique to use when ever we might be contacting plant sap. Having a clean collection of healthy-looking plants lets me be relaxed during routine watering instead of using a hazmat suit and a robot for all contact with my plants. It is not worth taking up growing time and space for a virus infected plants. A few growers have rare heirloom plants that are very valuable and keeping them to use various approaches to eliminate virus are worth a try. These can be kept separated from others. I am not in that situation so virus positive means trash can for the plant and pot.


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## southernbelle (Jul 16, 2021)

UPDATE: Testing of all plants completed and these figures hold. NO Paphs or Phrags were positive!! Thank you Hadley and Bill (although I do realize Catts and Phals, being cloned, always show a larger % of virused plants).


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## JustinR (Jul 18, 2021)

Oh that's too bad, was that fusarium or something else? Were there any outward signs on the plants that tested positive, e.g. poor growth, aborted growths, leaf discoloration etc?


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## southernbelle (Jul 18, 2021)

JustinR said:


> Oh that's too bad, was that fusarium or something else? Were there any outward signs on the plants that tested positive, e.g. poor growth, aborted growths, leaf discoloration etc?


Justin, fusarium is not a virus, but a fungus. This was all Oncidium Ring Spot Virus (ORSV) or Cymbidium Mosaic Virus (CymMV). Mostly CymMV, but there were a few OSRV positive and one or two that were positive for both! These are the two viruses that most often attack orchids and the two that tests are readily available for from Agdia and one other company. Viruses are easily spread by the sap (plant fluids) on hands or cutting tools that have not been properly disinfected (which takes some doing). Also when repotting, or from watering run off (according to Keith Davis in NC who usually has tested things through UNC, before he makes those types of proclamations.) 
So, since a few of my virused plants were seedlings, it's most likely whatever plants I had that came in virused, I also did some spreading myself. Apparently, unless seed is propagated wet (by cutting into the pod to harvest the seeds) rather than dry harvesting the seed (when the pod bursts), seed propagating of plants should not spread virus. Since cattleyas and phals are cloned, viruses can be transferred that way also, the reason so few paphs and phrags are usually virused and none of mine were. 
So now that I've tested everything, and certainly will continue to test any new plants that come in, I should be able to trust my collection will remain virus free. I will still disinfect clippers between each plant because other things (bacterial infections etc.) can be spread by using the same clippers on more than one plant without disinfecting. 
I really thought I was being careful by disinfecting clippers with TSP (Tri-Sodium Phosphate) soak (mixed so concentrated it would precipitate out, for 10 min to overnight) as told to by the local orchid vendor between plants, but apparently that is not really effective, as I learned the hard way! 
Now, I wear disposable nitrile gloves when I repot each plant and use a separate set of clippers while working on each plant, that then are disinfected by a 3 step process (rinse with soap and water, then Sodium Hydroxide/Virkon S, each 5-10 min) before being used again. I never re-use mix, pots or stakes, etc. This process was recommended by a large grower (with the science to back it up) who I believe is in CA, if I remember correctly. Sounds excessive, I'm sure to most, but I don't ever intend to take this kind of hit again, either financially or from a time standpoint.
Oh, to your question regarding seeing signs. In some cases there was color break on the flowers, an obvious sign of virus. In other, black/purple spotting on the leaves that at first I thought was from too much light, but it was suggested on this forum to be virus and I checked--it was! In some cases the plants had grown and flowered reasonably well several times, but the last flowering was unspectacular both in number and quality of blooms. In a few it was just failure to thrive, but in some cases, no signs had yet shown. So there you have it, hope this has been informative.


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## orchid527 (Jul 18, 2021)

southernbelle said:


> Justin, fusarium is not a virus, but a fungus. This was all Oncidium Ring Spot Virus (ORSV) or Cymbidium Mosaic Virus (CymMV). Mostly CymMV, but there were a few OSRV positive and one or two that were positive for both! These are the two viruses that most often attack orchids and the two that tests are readily available for from Agdia and one other company. Viruses are easily spread by the sap (plant fluids) on hands or cutting tools that have not been properly disinfected (which takes some doing). Also when repotting, or from watering run off (according to Keith Davis in NC who usually has tested things through UNC, before he makes those types of proclamations.)
> So, since a few of my virused plants were seedlings, it's most likely whatever plants I had that came in virused, I also did some spreading myself. Apparently, unless seed is propagated wet (by cutting into the pod to harvest the seeds) rather than dry harvesting the seed (when the pod bursts), seed propagating of plants should not spread virus. Since cattleyas and phals are cloned, viruses can be transferred that way also, the reason so few paphs and phrags are usually virused and none of mine were.
> So now that I've tested everything, and certainly will continue to test any new plants that come in, I should be able to trust my collection will remain virus free. I will still disinfect clippers between each plant because other things (bacterial infections etc.) can be spread by using the same clippers on more than one plant without disinfecting.
> I really thought I was being careful by disinfecting clippers with TSP (Tri-Sodium Phosphate) soak (mixed so concentrated it would precipitate out, for 10 min to overnight) as told to by the local orchid vendor between plants, but apparently that is not really effective, as I learned the hard way!
> ...


Just out of curiosity, were the virused seedlings phals or catts. Also, do you have any idea how old they were. The reason I ask is that I test seedlings that I buy, but I really don't know how long it takes to get to detectable levels in seedlings. In other words, I am concerned about false negative results.

Like you, I have not found any virused phrags. I thought I might stop testing them, but since they share trays of water when I go away on vacation, it seems to be too much risk.

Mike


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## southernbelle (Jul 18, 2021)

orchid527 said:


> Just out of curiosity, were the virused seedlings phals or catts. Also, do you have any idea how old they were. The reason I ask is that I test seedlings that I buy, but I really don't know how long it takes to get to detectable levels in seedlings. In other words, I am concerned about false negative results.
> 
> Like you, I have not found any virused phrags. I thought I might stop testing them, but since they share trays of water when I go away on vacation, it seems to be too much risk.
> 
> Mike


Ohhh, I'd do what I needed to do so that they did not share trays of water.

So, it was all catts that were positive except for for one Phal variety (3 plants)! I have (had) 6 phals, 3 of them were the variegated Phal Sogo Vivien marginata. All 3 from the same vendor and all 3 positive!! 
I gave away my phals except for these that were special or personal because phals take up a lot of room and when they bloom I move them upstairs to our living area they bloomed for such a long time, I ran out of room for other blooming plants.

Some of my positive catts were older plants (older than 5 years). There is the aspect that in cloned plants the virus might not show up for up to 5 years. Because cloning tissue is taken from new growth, usually the new growth outpaces the virus and can be clean even in a virused plant, but sometimes it takes some time for it it to show up. I have mericlones of older plants that are virused that are clean, so far. One is Rlc. Lawless Walkure 'The Ultimate'. I had one that was virused. Spoke to the vendor because it was a gorgeous flower and asked for an original division. Well the original plants are virused, so no clean ones there, only mericlones are clean (usually). I got one of those. I will test yearly for a couple of years, just to be safe, even though this plant is clearly older than 5 years old and blooming size.
Re seedlings, I don't know how long it would take it to show, but I would think (what do I know) that if it were infected from seed, it would be young. My seedlings were all NBS that were positive. Oh, and when you test, test new growth. At first, I thought I was being smart testing old growth since the cut leaves would not be around as long. Well, I outsmarted myself as the virus is most apparent in the new growth I've read, so I always test one of the newest one or two leaves now.


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## terryros (Jul 19, 2021)

Deb, you have really learned your stuff and are presenting it very well. In that most recent round of testing were any more Catts positive?


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## southernbelle (Jul 19, 2021)

Terry, thank you!! Coming from you I really appreciate it!! No, all catts had been previously tested. Paphs and phrags and a couple of phals were left which, thankfully, all tested negative.


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## Carmella.carey (Mar 9, 2022)

Hi its Patrick from the VOS thank you for telling me about SlipperTalk


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## southernbelle (Mar 9, 2022)

Welcome Patrick! It was great meeting you at the VOS show. It’s very exciting to see someone so young as passionate and knowledgeable about growing orchids. You will have a bright future, I know. And this is the mother lode of great info.


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## Carmella.carey (Mar 9, 2022)

Are you a member of the VOS and if so will you be at the meeting next week?


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## southernbelle (Mar 9, 2022)

Yes, I am a member and I hope to be at the next meeting. Right now I have a commitment that I’m trying to change.


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## Carmella.carey (Mar 9, 2022)

So I've been on a testing spree since we talked at the show setup day and I have found most of my plants from Chadwick's have Cymbidium mosaic virus and odontoglossum ring spot that made me curious so I pulled some of my Catts out of their pots and cut some of the old bulbs off and found a purple ring in the rihizome so yes some plants had CMV ORSV and fusarium all in one cattleya so my question is what do you do with these virused plants? And I hope its not what I think


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## Carmella.carey (Mar 9, 2022)

They have things like this.

Patrick


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## Greenpaph (Mar 9, 2022)

What did use for testing and how much did it cost?


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## Carmella.carey (Mar 9, 2022)

I used the Agdia CMV and ORSV rapid test kit and it was a little less tnan $13 a test and they come in packs of 25 and 50 they look like this and you just cut a leaf tip open the bag put the leaf in smash it up I use a spoon and put the stick in and you get the results right there.
Patrick


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## terryros (Mar 9, 2022)

I would infer that Patrick used Agdia test strips. There are people that will keep a virus infected plant if its growth and flowering seem normal. There are others who don’t/wont test - don’t ask the question if you don’t want the answer. However, the plant continues to be a source of infection for other plants. Many of us would trash any virus infected plant. That is what Deb and I did and continue to do. Serious collectors and breeders will keep a prized infected orchid because methods are developing to produce “clean” mericlones from them. I would say that most of my virus positive plants had something in their growth, leaves, or flowers that said something wasn’t quite right.


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## Carmella.carey (Mar 9, 2022)

I don't know what I'm going to do with the virused plants so far there's 17 known plants with virus and probably more I've been keeping them separate from my other orchids while I decided what to do I know that the virus probably didn't spread via un cleaned cutting tools in my care I use a fresh razor blade not from plant to plant but from cut to cut do to fungas like fusarium if treated properly with a sistemic fungicide a plant can grow out of fusarium with clean growth and cutting into unhealthy tissue and then into healthy tissue re introduce infection so I'm vary cautious. Do you know any other way virus can spread other than open tissue?


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## monocotman (Mar 10, 2022)

What you do with a virused plant is very much up toy you. Some people bin them. Some bin the ones that show virus in the flowers, not all do. Others ignore it.


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## southernbelle (Mar 10, 2022)

Carmella.carey said:


> They have things like this.View attachment 32870
> 
> Patrick



Oh, Patrick. I am so very sorry… I know that you must feel so discouraged and devastated. Unless you test a plant right when you get it, you can’t be sure the virus came from the grower or from your handling, but I would definitely let Chadwick’s know. I did have some virused plants from them.
As David (monocotman) said above, some people just ignore it. On occasion a virused plant shows no signs and grows reasonably well. I know a grower with that philosophy. I won’t but from them anymore as several plants I had were infected. Unfortunately, unless you can isolate the plants and are extremely diligent every time you touch them or move them (to wear disposable gloves and disinfect before you touch another plant), you run the risk of spreading the virus throughout your collection. Any plant sap, fluid or tissue can spread it, so with catts that exude sap it’s extremely difficult. I had to destroy a third of my collection that I found were virused, along with the stakes, tags, pots, etc. I never reuse a pot or stake, unless it’s for the same plant. I had begin to acquire several original or awarded divisions and could not risk losing those as I could not afford to replace them. You are very young and this will be a lifetime hobby and maybe profession for you, so the decision you make at this stage is a very important one for your future in orchids. 
Keith Davis, the renowned cattleya grower from North Carolina who does a lot of orchid research with UNC, says that even watering can spread virus because it can be in the runoff. But really our hands and tools are the worst culprits at spreading it, especially when grooming or repotting. Insects like thrips, etc., can also spread it from plant to plant.
My, and a scientific friend’s, research led us to a 3 step process for disinfecting my tools from a grower in CA. No one chemical does the job on all viruses according to the experts. So soap and water, then a 10 min soak in lye, then a 10 min soak in Virbac rinsing well between each, then air drying. (I will bring the info to you, as I am coming to the meeting now, or if you PM me I will email it to you.) It’s a true pain in the rear, but I’m told by experts that no one chemical does it effectively. The hard part is then keeping the sink, etc. clean. The Smithsonian disinfects and then puts everything in an autoclave!! They also have each plant on its own sterile plastic plate so it is never set on a surface any other plant sits on, and wear disposable gloves and change between touching plants. With some rare, irreplaceable plants in their collection they take no chances.
Once I destroyed the infected plants and now test everything new that comes in immediately, I’ve relaxed a little, but still am diligent. Your photo is something I would suspect. I had a plant with black spotting on leaves not unlike the purple that occurs in high light situation and asked about it on this forum. Someone very wise suggested virus and he was right! Anything unusual on a leaf or flower, or a plant that simply doesn’t thrive makes me suspect it and I will test again. 
One encouraging thing I can say is you figured this out at a relatively early stage in your growing rather than years down the road when it could have been even more costly.


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## southernbelle (Mar 10, 2022)

Your use of razor blades is wise. I’ve never had fusarium, thankfully, so have started using a razor blade for each plant tucking it in the side of the pot and replacing it if it starts to rust.


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## Carmella.carey (Mar 10, 2022)

southernbelle said:


> Oh, Patrick. I am so very sorry… I know that you must feel so discouraged and devastated. Unless you test a plant right when you get it, you can’t be sure the virus came from the grower or from your handling, but I would definitely let Chadwick’s know. I did have some virused plants from them. Unfortunately, unless you can isolate the plants and are extremely diligent every time you touch them or move them (to wear disposable gloves and disinfect before you touch another plant), you run the risk of spreading the virus throughout your collection. Any plant sap, fluid or tissue can spread it, so with catts that exude sap it’s extremely difficult. I had to destroy a third of my collection that I found were virused, along with the stakes, tags, pots, etc. I never reuse a pot or stake, unless it’s for the same plant.
> Keith Davis, the renowned cattleya grower from North Carolina who does a lot of orchid research with UNC, says that even watering can spread virus because it can be in the runoff. But really our hands and tools are the worst culprits at spreading it, especially when grooming or repotting. Insects like thrips, etc., can also spread it from plant to plant.
> My, and a scientific friend’s, research led us to a 3 step process for disinfecting my tools from a grower in CA. No one chemical does the job on all viruses. So soap and water, then a 10 min soak in lye, then a 10 min soak in Virbac rinsing well between each. (I will bring the info to you, as I am coming to the meeting now. Or if you PM me I will email it to you.) It’s a true pain in the rear, but I’m told by experts that no one chemical does it effectively. The hard part is then keeping the sink, etc. clean. The Smithsonian disinfects and then puts everything in an autoclave!! They also have each plant on its own sterile plastic plate so it is never set on a surface any other plant sits on, and wear disposable gloves and change between touching plants. With some rare, irreplaceable plants in their collection they take no chances.
> Once I destroyed the infected plants and now test everything new that comes in immediately, I’ve relaxed a little, but still am diligent. Your photo is something I would suspect. I had a plant with black spotting on leaves not unlike the purple that occurs in high light situation and asked about it on this forum. Someone very wise suggested virus and he was right! Anything unusual on a leaf or flower, or a plant that simply doesn’t thrive makes me suspect it and I will test again.
> One encouraging thing I can say is you figured this out at a relatively early stage in your growing rather than years down the road when it could have been even more costly.


I have separated the known virused plants, and even the original C.Horace from 1936 was virused I was expecting that do to its many years of unknown care and the picture of the leaf is a jungle collected maxima with CMV  and with the scale spreading it too gerr on top of it I use clay pots so I've been bleaching pots then reusing them gerr again  it's all ok I will talk to you more about this at the OS meeting 
Thanks so much, Patrick


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## southernbelle (Mar 10, 2022)

Carmella.carey said:


> I have separated the known virused plants, and even the original C.Horace from 1936 was virused I was expecting that do to its many years of unknown care and the picture of the leaf is a jungle collected maxima with CMV  and with the scale spreading it too gerr on top of it I use clay pots so I've been bleaching pots then reusing them gerr again  it's all ok I will talk to you more about this at the OS meeting
> Thanks so much, Patrick


The C. Horace and jungle collected one are certainly two worth the work of isolating and keeping. So, if you have the space you could keep any that are growing well. It would be pretty unusual if the C. Horace was not virused, due simply to its age, at a time when they didn’t even know what viruses were in orchids. Besides, those have tremendous sentimental value being a gift from Chadwick. Re the clay pots, I’ve heard they can be baked at a high temp for a time, but I don’t remember details, nor can I attest to it being effective, as I don’t know the temp etc.


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## terryros (Mar 10, 2022)

I am one of Debra’s email orchidpals and we have fiddled with various things, including virus. I have a Horace ‘Maxima’ mericlone and it is Agdia strip negative. If the mericloning is done very carefully with the correct part of the tissue, a classic Cattleya that is virused can be sort of maintained. Of course, not all mericlones are as good as the original, but some are or can even be a bit better. I think I wouldn’t obtain an old classic Cattleya without virus testing. Afraid this applies to species and hybrids. Almost all young seedlings seem to be virus negative, even if made with a virused parent. I try to be careful with disinfection, but I am not perfect. My best defense is having a clean collection.


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## tomp (Mar 11, 2022)

southernbelle said:


> The C. Horace and jungle collected one are certainly two worth the work of isolating and keeping. So, if you have the space you could keep any that are growing well. It would be pretty unusual if the C. Horace was not virused, due simply to its age, at a time when they didn’t even know what viruses were in orchids. Besides, those have tremendous sentimental value being a gift from Chadwick. Re the clay pots, I’ve heard they can be baked at a high temp for a time, but I don’t remember details, nor can I attest to it being effective, as I don’t know the temp etc.


 understand 400 F for 1 Hour


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## Carmella.carey (Mar 11, 2022)

terryros said:


> I am one of Debra’s email orchidpals and we have fiddled with various things, including virus. I have a Horace ‘Maxima’ mericlone and it is Agdia strip negative. If the mericloning is done very carefully with the correct part of the tissue, a classic Cattleya that is virused can be sort of maintained. Of course, not all mericlones are as good as the original, but some are or can even be a bit better. I think I wouldn’t obtain an old classic Cattleya without virus testing. Afraid this applies to species and hybrids. Almost all young seedlings seem to be virus negative, even if made with a virused parent. I try to be careful with disinfection, but I am not perfect. My best defense is having a clean collection.


Well I wouldn't try to mericlone the original Horace from 1934 because then it wouldn't be the original Horace. I will keep testing


tomp said:


> understand 400 F for 1 Hour


Thank you so much time to go cook some pots
Patrick


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## terryros (Mar 11, 2022)

I think that some collectors of rare and treasured antique Cattleyas that are virus infected have them isolated and handled carefully IF they continue to grow and bloom acceptably. When flower and leaf defects are obvious, I think you can only breed with them (maybe best as a pollen donor) or try the specialized mericloning process and hope that some plants end up virus free. Many of these plants will continue to deteriorate and die. I don't think there is any scientific hint that a virus positive plant can be treated and become virus free. When I buy a mericlone of a classic, I always hope that mine might turn out even better than the original, as happens infrequently in some batches of mericloning. Think percivaliana 'Summit' versus 'Mendenhall Summit'.


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## Carmella.carey (Mar 11, 2022)

terryros said:


> I think that some collectors of rare and treasured antique Cattleyas that are virus infected have them isolated and handled carefully IF they continue to grow and bloom acceptably. When flower and leaf defects are obvious, I think you can only breed with them (maybe best as a pollen donor) or try the specialized mericloning process and hope that some plants end up virus free. Many of these plants will continue to deteriorate and die. I don't think there is any scientific hint that a virus positive plant can be treated and become virus free. When I buy a mericlone of a classic, I always hope that mine might turn out even better than the original, as happens infrequently in some batches of mericloning. Think percivaliana 'Summit' versus 'Mendenhall Summit'.


I will keep testing and maybe if most of my collection is virused I should just keep everything except plants that don't grow well or have color break and things with the flowers and isolate the non-virused plants and keep them clean. What do you think is that a good idea? Or what
Patrick


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## orchid527 (Mar 11, 2022)

Carmella.carey said:


> I will keep testing and maybe if most of my collection is virused I should just keep everything except plants that don't grow well or have color break and things with the flowers and isolate the non-virused plants and keep them clean. What do you think is that a good idea? Or what
> Patrick


If you intend to keep the virused plants, then you don't need to test anymore. Eventually, you will have problems with thrips, or you will be careless one day, and the virus will spread to your clean plants. You can't keep your collection clean if you have any virused plants. It just won't work. Maybe if the virus were visible and brightly colored and you were always vigilant, you might have a chance. There are just two paths forward. Either will work. 

Test everything, toss infected plants and implement an effective barrier strategy of restricted purchases and testing.

OR

Don't test, throw away suspicious and weak plants, assume the rest are infected and act accordingly. 

Mike


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## Happypaphy7 (Mar 11, 2022)

I'm with Mike on this. 
It's like playing with fire. The risk of ruining other clean plants in the collection will always be there, and quite high unless you have a completely isolated greenhouse away away from the rest of your collection. 
Everytime I go visit a Cattleya nursery, I always find quite a few flowers infested with thrips. I see them crawl around on the flowers and I see the damage along the edges of the flowers.


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## southernbelle (Mar 11, 2022)

orchid527 said:


> If you intend to keep the virused plants, then you don't need to test anymore. Eventually, you will have problems with thrips, or you will be careless one day, and the virus will spread to your clean plants. You can't keep your collection clean if you have any virused plants. It just won't work. Maybe if the virus were visible and brightly colored and you were always vigilant, you might have a chance. There are just two paths forward. Either will work.
> 
> Test everything, toss infected plants and implement an effective barrier strategy of restricted purchases and testing.
> 
> ...


Mike:
That’s what I did. My collection was about 100 plants mostly catts, next paphs, a few phrags and phals. A third were virused. As soon as I found a virus positive plant, I destroyed it. A few were seedlings acquired a couple of years prior from Orchids Ltd. I know those had to be cross-infected by me or by thrips, because Jerry is very diligent and would never wet harvest seeds which could pass on virus in seedlings. Fortunately none of my best or most sentimental plants were virused. And, because of being relatively new to serious collecting, I had no original divisions or divisions of awarded plants at that point. So I was able to cut my losses and move on. Now anything that comes in is tested and anything which fails to thrive or has a funky leaf, spot or flower is re-tested. So far, so good. And I’m as diligent as I can be about hygiene, but far from perfect despite my best efforts. When I repot, I always feel like I should buy stock in disposable nitril gloves because I’m so aware of everything I or the plant touches and how hopeless it seems to keep “clean”. I had grown roses before and was aware of not spreading disease or virus, but then we just dipped our clippers in alcohol after each cut and all was well. That does not work with orchid viruses. It might not have worked way back then with rose viruses either, but ignorance was bliss I guess.


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## Carmella.carey (Mar 11, 2022)

southernbelle said:


> Mike:
> That’s what I did. My collection was about 100 plants mostly catts, next paphs, a few phrags and phals. A third were virused. As soon as I found a virus positive plant, I destroyed it. A few were seedlings acquired a couple of years prior from Orchids Ltd. I know those had to be cross-infected by me or by thrips, because Jerry is very diligent and would never wet harvest seeds which could pass on virus in seedlings. Fortunately none of my best or most sentimental plants were virused. And, because of being relatively new to serious collecting, I had no original divisions or divisions of awarded plants at that point. So I was able to cut my losses and move on. Now anything that comes in is tested and anything which fails to thrive or has a funky leaf, spot or flower is re-tested. So far, so good. And I’m as diligent as I can be about hygiene, but far from perfect despite my best efforts. When I repot, I always feel like I should buy stock in disposable nitril gloves because I’m so aware of everything I or the plant touches and how hopeless it seems to keep “clean”. I had grown roses before and was aware of not spreading disease or virus, but then we just dipped our clippers in alcohol after each cut and all was well. That does not work with orchid viruses. It might not have worked way back then with rose viruses either, but ignorance was bliss I guess.


I use fresh razor blades as I've said with each cut but if I have a really really thick rizome and have to use pruners I dip them in alcohol then light them on fire and repeat four times before using them I wonder if that actually works.
Patrick


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## southernbelle (Mar 12, 2022)

It’s a technique used by many growers, minus the alcohol. I asked Art Chadwick at the show what he does and he uses razor blades when he can and a torch when clippers are used. I’ve tried the torch, but don’t like it. How hot, how long? Too variable for me. Plus it dulls clipper blades pretty quickly and they have to be sharpened. I’d rather use razor blades and soak when I have to use clippers. I have a torch recommended by Keith Davis (high intensity type) that I tried for a couple of days—it’s barely used I’d sell really cheaply if you need one.


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## Carmella.carey (Mar 12, 2022)

southernbelle said:


> It’s a technique used by many growers, minus the alcohol. I asked Art Chadwick at the show what he does and he uses razor blades when he can and a torch when clippers are used. I’ve tried the torch, but don’t like it. How hot, how long? Too variable for me. Plus it dulls clipper blades pretty quickly and they have to be sharpened. I’d rather use razor blades and soak when I have to use clippers. I have a torch recommended by Keith Davis (high intensity type) that I tried for a couple of days—it’s barely used I’d sell really cheaply if you need one.


I have the torch he recommended when he spoke at the Odom's Orchids Cattleya symposium in 2019 I am also not sure how long or how hot as you've said the variables are infinite.
Patrick


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## Carmella.carey (Mar 12, 2022)

Snow in March in Virginia crazy just crazy. Is it snowing in spotsy?
Patrick


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## southernbelle (Mar 13, 2022)

Carmella.carey said:


> Snow in March in Virginia crazy just crazy. Is it snowing in spotsy?
> PatrickView attachment 32927


Yep, about the same amount as you.


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## NEslipper (Mar 19, 2022)

I just went through a batch of 25 Agdia strips to test all my old, heirloom cattleyas. I haven’t tested any seedlings yet, but those are relatively low risk as they’ve been purchased from Orchids Limited, SVO, and Steven Christoffersen. In terms of the old timers, 2 out of 25 were virus positive, 1 ORSV and 1 CymMV. The two virus positive plants are the oldest plants in my collection, so it’s not surprising they contracted viruses in 100+ years of culture. I had already been growing them in an entirely separate room from the rest of my catts out of an abundance of caution. The ORSV positive plant I will likely discard, but the CymMV+ plant is one of my most vigorous growers and bloomers - the leaves and flowers are immaculate, not a blemish to be found. It has so much sentimental value, I could never part with it. All of my “ugliest” looking plants in terms of blemishes and streaks tested negative, emphasizing that you really can’t know until you test. All my plants from Chadwick’s, Waldor, and the Orchid Alley were negative.


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## Carmella.carey (Mar 19, 2022)

H


NEslipper said:


> I just went through a batch of 25 Agdia strips to test all my old, heirloom cattleyas. I haven’t tested any seedlings yet, but those are relatively low risk as they’ve been purchased from Orchids Limited, SVO, and Steven Christoffersen. In terms of the old timers, 2 out of 25 were virus positive, 1 ORSV and 1 CymMV. The two virus positive plants are the oldest plants in my collection, so it’s not surprising they contracted viruses in 100+ years of culture. I had already been growing them in an entirely separate room from the rest of my catts out of an abundance of caution. The ORSV positive plant I will likely discard, but the CymMV+ plant is one of my most vigorous growers and bloomers - the leaves and flowers are immaculate, not a blemish to be found. It has so much sentimental value, I could never part with it. All of my “ugliest” looking plants in terms of blemishes and streaks tested negative, emphasizing that you really can’t know until you test. All my plants from Chadwick’s, Waldor, and the Orchid Alley were negative.


How old were these "old timers"?


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## NEslipper (Mar 19, 2022)

The oldest are species trianaei that were ripped from the jungle in the late 1800s. The majority are more recent hybrids from the 1930s and 1940s. 


Carmella.carey said:


> H
> How old were these "old timers"?


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## southernbelle (Mar 20, 2022)

NEslipper said:


> I just went through a batch of 25 Agdia strips to test all my old, heirloom cattleyas. I haven’t tested any seedlings yet, but those are relatively low risk as they’ve been purchased from Orchids Limited, SVO, and Steven Christoffersen. In terms of the old timers, 2 out of 25 were virus positive, 1 ORSV and 1 CymMV. The two virus positive plants are the oldest plants in my collection, so it’s not surprising they contracted viruses in 100+ years of culture. I had already been growing them in an entirely separate room from the rest of my catts out of an abundance of caution. The ORSV positive plant I will likely discard, but the CymMV+ plant is one of my most vigorous growers and bloomers - the leaves and flowers are immaculate, not a blemish to be found. It has so much sentimental value, I could never part with it. All of my “ugliest” looking plants in terms of blemishes and streaks tested negative, emphasizing that you really can’t know until you test. All my plants from Chadwick’s, Waldor, and the Orchid Alley were negative.


You were fortunate they have been separate and have not cross infected any others. It speaks of your good habits.


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## NEslipper (Mar 24, 2022)

Thank you. I feel confident in my abilities to keep them separate, and that level of risk is acceptable to me. What I struggle with is the things I can’t control, like pests. Even with quarantining new plants, and preemptively treating, I did have a thrip outbreak this past year. It’s possible they came in through an open window or some other means, so the origin of the outbreak is unknown. They left my cattleyas alone, and thankfully it doesn’t seem any cross-contamination occurred, but even with constant vigilance these things can happen. For now I still plan to keep the infected plan, but I will reassess periodically.


southernbelle said:


> You were fortunate they have been separate and have not cross infected any others. It speaks of your good habits.


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## Carmella.carey (Mar 29, 2022)

Hi Deb,
Do you know any thing about tabaco mosaic virus?
My dad smokes and I wonder if that smoke could drift into the greenhouse and infect the plants.
Patrick


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## southernbelle (Mar 30, 2022)

Patrick:
I do remember reading something about it back when I investigated this. I’m not sure it mentioned the smoke, but I think it was referring to it spreading to plants from the hands of smokers. Could it be on things a smoker touches and transfer? I don’t know. Google it or search AOS for it. I found this article about TMV on orchids (and spread between orchids) but not about how they can get it in the first place.


https://ipm.illinois.edu/diseases/rpds/614.pdf


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## southernbelle (Mar 30, 2022)

Carmella.Carey
I found this. No to smoke spread, yes to anything a smoker’s hands have touched (after they have touched tobacco products). Virus lies dormant on everything inorganic for a very long time (years?) and can be picked up and spread to plants by touch. Don’t forget about nicotiana and other type garden plants, if planting or growing those. 








Tobacco Mosaic Virus (TMV)


Tobacco mosaic virus (TMV) is named for one of the first plants in which it was found in the 1800s. However, it can infect well over 350 different species of plants.




extension.psu.edu


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## southernbelle (Mar 30, 2022)

Carmella.Carey
I’ve been thinking about this… Agdia’s Immunostrip for Orchid viruses only tests for CymMV and ORSV which are the two most common viruses to attack orchids. They do have a separate Immunostrip for TMV that tests for almost 300 strains but it doesn’t say specifically TMV-O which is the one orchids can get. One of the articles mentioned something about the way cigarette tobacco is processed it makes it less likely to carry it, I think (don’t know if it was one I sent link to.)
And, Agdia’s Immunostrip for TMV cross-reacts with ORSV so you could get a false positive if the plant was infected with that. Curiously enough their test for CymMV and ORSV does not cross-react with TMV…
Since you have decided not to test beyond what you have and only destroy plants that don’t grow well or show signs of virus, frankly, I wouldn’t worry about it. 
On the other hand, if you have a plant that is important to you and it’s negative for the first two (with symptoms), you could then test for TMV knowing there would be no cross-reaction since you have ruled out ORSV. Just a thought, but if you are going to destroy the plant anyway because of symptoms, then don’t waste the $$.


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## Carmella.carey (Mar 30, 2022)

Well Deb my mom is vary happy that if I ever decided to use any tobaco product I would be infecting my whole collection so as long as I have orchids (or really any plants) I will not be able to smoke.
Patrick


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