Virus testing on Cattleyas

[Carmella.carey]

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

 

[terryros]

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.

 

[Carmella.carey]

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?

 

[monocotman]

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.

 

[southernbelle]

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.

 

[southernbelle]

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.

 

[Carmella.carey]

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

 

[southernbelle]

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.

 

[terryros]

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.

 

[tomp]

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

 

[Carmella.carey]

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

understand 400 F for 1 Hour

Thank you so much time to go cook some pots
Patrick

 

[terryros]

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'.

 

[Carmella.carey]

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

 

[orchid527]

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

 

[Happypaphy7]

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.

 

[southernbelle]

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

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.

 

[Carmella.carey]

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

 

[southernbelle]

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.

 

[Carmella.carey]

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

 

[Carmella.carey]

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