Viruses and orchid collections

[james mickelso]

After growing orchids for quite a few years now, all of a sudden I am hearing about viruses. Few of my plants came direct from growers, for most of them came from garage sales, dumpsters, friends throwaways, HD, TJ's, and lots of different club auctions and donation tables. Few ever had color break or mal-formed leaves. Most grew great, flowering every year on schedule with very nice fully formed flowers and pushed new buds every growing season. I have had less than, and more than 100's of orchids. I recently sold over 400 orchids because I was planning to move. I have had bacterial infections, fungal infections, and bugs in my collections and I am positive most were virused. But few showed any problems and except for a handful most never showed any defineable ill-effects. And I had lots of them for a long time. So I wonder, from my experience, what is the problem with virused plants to most of us who grow orchids as purely a hobby? Yes if I was selling them on the market, or had very rare or hard to find orchids, or were propagating them for seed or crosses, I would definately want to make absolutely sure none were virused. But...an orchid costs about $25 or more and that to me is a lot of money just to throw away because a test strip said it was virused. I'd like to know how many on this board are really concerned if their collection has virused plants? Before the advent of test strips which are not fool proof and show quite an error factor anyway, orchids grew in many collections and no one seemed to report any problems. If there are seemingly so many virused plants now showing up in collections all over the place, would it not be correct in assuming that virused plants have been around in most collections for a long long time? Or have we an orchid viral pandemic on our hands? Just wanting to know how many are really concerned with whether their collection is virused and how many have unexplained problems with the plants in their collectiions that may be linked to viral infections? I have recently read a great deal on plant viruses and especially viruses that affect orchids. So I don't need to have them explained to me. Just your opinions on the threat of having a virus invading your collection.

[Ray]

I have heard that ALL phalaenopsis plants are virused. I don't know if that's true, but it wouldn't surprise me.

Personally, I am convinced that - like us - living creatures harbor populations of whatever they have ever been exposed to. In people, shingles is a classic example: if you ever had chicken pox, you are carrying the virus, and are therefore susceptible to getting shingles. So basically, as long as your system is healthy and not overtaxed in some way, you can live symptom-free. In my own case, I got shingles in late 2007, only to be diagnosed with metastatic malignant melanoma the following spring. I figure my immune system was stressed, so the virus was able to take hold.

That said, it would follow that if you do a good job with the overall culture of your plants, keeping them relatively unstressed, it is very likely that you will rarely see the symptoms of viruses in your collection, even if they are present.

That is not to say that viruses are not bad, and that you need not bother to do what you can to prevent the spreading of them. If you have a plant with color break or some other virus symptom, I feel the best course of action is to get "Typhoid Mariae" out of your collection fast. You're not likely to get it to recover, and there is no sense in risking it.

[NYCorchidman]

While some botanists believe that all plants are virused. It is a good theory, but I personally do not believe that is the case.

Now, regarding that all phalaenopsis being virused, it is simply not true (some greenhouse test data show that the prevalence of virused plants are somewhere from 0.5 to 30%, never 100%) unless these figures were cooked up to make people less worried.

It might have been exaggerated from the fact that there have been cases where virused plants were used in the cloning process producing tons of virused plants and distributing them in the market.
Also, before this virus thing caught much attention, people didn't know better.
Bare hands used when deflasking seedlings and the list goes on and on.
Now they are trying as much as they could in handling plants properly to reduce the virus infection.

Even then, it is not entirely possible to stop viruses from spreading. We (we as in everyone, not just us consumers) can always do better to keep the virus down as much as possible though.

Do I care about it? yes! it bothers me a lot actually.
I thought about testing all my collection, but I decided to treat all plants as if they were virused and practice good culture. It is quite a heache the more I think about it.

Those that display suspicious symtoms, I dump them out. I grow plants to see healthy growths and beautiful blooms, so I don't care if they are virused or not. If they don't grow or flower well, or show funny things on them, I don't want them. Simple!

I do not give away my plants that I think have issues. It is just unethical. Then again, I do give away plants displaying no symptoms (but could still be virused). Some virus could travel via this route I guess although not intended.

[quiltergal]

I would never throw out a plant that grows and blooms normally. I have no intention of strip testing my plants. It's too expensive and the results are inconclusive (too many false positives). So unless it shows color break or some other leaf issues I'm not going to worry about it. If I have a plant that does show those signs then I toss it. I'm not growing professionally, and my plants rarely come in contact with anyone else's.

It is really unfortunate that we can't seem to get any plants out of Taiwan that aren't virused. I would recommend buying from a grower here in the US that you trust. Many of them do their own breeding/flasking/deflasking so your odds of having a healthy virus free plant are quite a bit better. That is not to say that all the growers in the US are trustworthy.

[camille1585]

I think you need to nuance the all Phals are virused statements. It's more like " all mass propagated orchids from asia are virused".

Like the OP says, I think how you feel about virus depends on how you feel about your collection. For me the collection is about the blooms and stress reducing effect tending the orchids seems to have on me. I'm not interested in buying award quality plants, or getting seriously involved in breeding, or propagating to sell to other people. So virus is something unpleasant, but symptomless plants are not the end of the world for me. BUT if I were to start collecting for any of the other reasons I state above, THEN I would aggressively cull out virused, yet symptomless plants and be very demanding when purchasing plants.

The fact is that virus is everywhere in nature. I can across an article at work about the prevalence of virus in wild cabbage populations on the southern coast of England. 30 to 98% of the tested plants were positive of virus, with many of them positive for ALL 6 of the viruses tested for! Yet the plants are happily growing.

[tucker85]

There have been some excellent posts on this thread. I agree with most of the comments made. I read that scientists have discovered that there are thousands of viruses in a drop of seawater. In humans the severity of a virus can range from the common cold to Ebola or AIDS. Before I knew about sterilizing my tools I got a bad virus in my orchid collection and lost about 50 orchids. They all started growing poorly and showing severe color break and malformation of the flowers. For the last 10 years I've used proper sterilization methods on my tools and I've had no more problems with the spread of viruses. If I find a plant that shows severe signs of a virus, I throw it away. But when I have a plant that I'm suspicious of but not sure, I don't fear keeping it in my collection for another blooming season, to see for sure. I just use sterile technique so it won't spread.

[camille1585]

Same here, though tolerant of virus in my collection, I don't want to spread it either so do my best to use good cultural practices. And any suspicious orchids get isolated from the rest, right now I have 4 of them living on the kitchen windowsill. 2 have developed full blown symptoms, and I'm still on the fence about the other 2.

[Cym Ladye]

98% of the orchids I grow are Cymbidiums and they are primarily for show and/or seedlings or young stock for submission for awards. Since they are "out and about" I am constantly testing for virus. Many divisions I place with other hobby growers, so it is important that they go out clear at the time. I no longer grow phals.

On the other hand, I have an area well separated from the rest of the collection where I have at the moment three, tested positive, "too good to throw out" plants. They do show minor leaf symptoms but no flower deformation - yet. They are on their third year from positive testing and are again in heavy spike. If there is color break, they will go to the goats. I have been told by some that eventually a virus will slowly destroy the plant with color break and in leaf symptoms in spite of good culture. It will just take longer if the culture is optimal. I suspect it may also depend on which virus the plant has as to a terminal affect..

CL

[quiltergal]

I know I am most likely dealing with PhCSV in my Phals. I have already tossed more than half of them. Per some of the studies I have read it originated in Taipei China in 2007. It is mechanically transmitted so I have been diligent in sterilizing tools, pots, metal stakes etc. I toss the bamboo stakes and will not reuse them again. I have been trimming the bad parts of the leaves off to see if that will get rid of it. Not much is known about this virus, so I feel like I'm kind of rolling the dice and hoping for the best.

I hate to think about how much money ended up in the trash!

[Leafmite]

I don't test if there are no symptoms but I tend to keep the orchids away from my prize plants. I am likely going to get rid of some of my orchids this summer and keep a smaller number and concentrate more on my other plants. I already have lost some interest in the whole thing...haven't decided whether to remain a member of the orchid society yet....