Question about virus

[gngrhill]

This may seem like a very stupid question, but ask it I must. I was doing some virus testing and after finding a couple that tested positive, I have decided to test my whole collection. ( yea, right, at $6 a pop and 100 plants) My question is , I have one that the line just barely showed up meaning low titer, would you keep that plant if it was one you could not easily replace, keeping it separate from the others, or would you toss it anyway ?

[Leafmite]

Originally Posted by gngrhill

This may seem like a very stupid question, but ask it I must. I was doing some virus testing and after finding a couple that tested positive, I have decided to test my whole collection. ( yea, right, at $6 a pop and 100 plants) My question is , I have one that the line just barely showed up meaning low titer, would you keep that plant if it was one you could not easily replace, keeping it separate from the others, or would you toss it anyway ?

Before pitching any orchids of which you are fond that may be difficult to replace, you may want to have them tested by a lab just to be certain. Critter Creek? I read somewhere that you should test everything at least twice as there are sometimes false positives or, if there is not enough of the virus present, false negatives.

I would keep the orchid in an isolated place and observe it. If it doesn't grow well, is slow to put out new growth, has weak new growth, has color break in the flowers or doesn't bloom when you expect it to bloom, this will prove that it is virused. A few years ago, I spoke with a professor who had spent his life collecting and growing all types of plants, including orchids and I asked him about viruses. He said that what he always noticed with virused plants was the lack of vigor. Even when the orchid/plant showed no other signs, it just didn't grow as well as it once did or as it should have been growing. When he would test it...virus.

Twice, I have found virused orchids. Both times, thankfully, I had reason to isolate them before they could infect anything else. One was an OS freebie, the other was healthy until I took it to an OS meeting and someone set a very nasty looking orchid against mine. The first, the freebie, didn't put out new growths when I expected and soon showed mosaic and ring patterns in the leaves...just like the pictures. The second had color break with the new flowers, delayed putting out the new growth until late in the summer...then the leaves began to get those tell-tale markings. Both were pitched, pot, medium and all.

I find that by only purchasing orchids from vendors with very high ratings, it very much improves the odds that the orchids will be healthy. Of course, someone who has used tobacco products could walk through a greenhouse, touch plants and infect them with virus but a vendor cannot prevent that.

[PaphMadMan]

Ideally, isolate it and re-test in a few months. False positives are always a possibility no matter how careful you are.

[katrina]

I think my first question to you would be why did you test them? Are there suspicious blemishes? Poor growth? Deformed/malformed/flowers? Color-break in the flowers?

I go w/the assumption that I likely have virus in the collection somewhere so I act accordingly and follow strict hygiene protocol. I've read enough articles that all say unless you are testing the minute a plant arrives and you have tested negative...it's best to assume you do have virus somewhere in the collection. So, with that in mind...I only test plants that do one of the above things and have created suspicion in my mind. Of all the plants that I've tested, only a few have ever tested positive.

The ones that tested positive were destroyed. And I would do the same thing w/any plant that tests positive if it's not growing well, bad flowers, or bad foliage. Even if it's rare.

I've never had a rare plant test positive so I don't know for sure how I respond but I suspect I would still destroy it...mainly because there must be something going on that prompted me to test it. If it's not growing well or the flowers are bad then, in my mind, there is no reason to keep it. What's the point in keeping a rare plant if it's ugly? Well, that's the way I look at it.

So...that was the long way of getting to...why did you test it? If it's got a flower problem or growing badly then I wouldn't want it any way. I figure there is no sense in taking up valuable space w/something doesn't look good and that could potentially infect other plants? If it's easily replaced then I would want to use the $6 toward a healthy new plant and save the tests for the next suspicious one.

That's just my opinion and if you talk to others you will likely get a variety of different opinions on the subject. In the end, you do what you're comfortable doing but if you opt to show the plant at a show or meeting then you really should let people know it's tested positive. Some folks are hyper-paranoid about virus and they won't want to even have their plants in the same room. Plus, even though transmission is highly unlikely in those settings...there is still a small chance and you wouldn't want to be responsible for that w/out having informed the others of the situation.

[Ray]

Originally Posted by katrina

I go w/the assumption that I likely have virus in the collection somewhere so I act accordingly and follow strict hygiene protocol.

That is some of the wisest advice I've ever seen on an orchid forum.

I am of the opinion that any virus a plant has ever been exposed to resides within it forever - just as is the case with people. As long as your culture is good, and the plant is not unduly stressed, that virus may not gain a stronghold and be a problem. If you see the symptoms Kat mentioned, by all means take action.

[Leafmite]

If you do prove that an orchid has a virus, unless it is something very, very valuable and there is a desire that it be used in hybridizing, there is no reason to keep it. It will eventually die anyway unless you give it the absolute best care (Really great care can mask symptoms and help halt the decline. Stress can bring out the symptoms more quickly). Still, even with the best care, the orchid will never be what it could have been without the virus.

[wintergirl]

Strict hygiene is the way to go. If you ever watch any of those videos where people just wipe their cutting tools with alcohol or watering all their plants in the same bath, you know they are spreading viruses.

---------- Post added at 01:04 PM ---------- Previous post was at 11:28 AM ----------

Speaking of viruses, I wonder if this plant on Ebay for $75 plus shipping looks virused to everyone.

Laelia Anceps Lineata Orchid Plant Selected Lineata Type Cattleya | eBay

[Leafmite]

It looks VERY suspiciously like virus to me. No wonder he doesn't accept returns....
If I had an orchid like that and could possibly have a logical explanation for the color break that wasn't virus, I would still put that (and anything that might have been near it) in quarantine (color break in a Cattleya...not something one risks). If there was no other explanation, I would immediately toss it and then put anything that had been near it in quarantine...then watch the rest of my collection.

[estación seca]

I had a lot of Datura wrightii growing all over my property. This is a magnificent Sonoran desert native angel's trumpet or jimson weed. It is in the nightshade family, along with tobacco, potato, tomato, petunia and eggplant/aubergine. All these are susceptible to tobacco mosaic virus. All tobacco products sold for smoking or chewing are infested with this virus, and the virus is viable in the open for years to decades.

A lot of my neighbors walk through the neighborhood daily. Somebody began throwing cigarette butts in my yard. I still haven't figured out who is doing this. Soon all my Datura showed the yellow mosaic pattern of virus infestation. I had to tear them all out. The virus can be passed through seed. I kept some seed and will try again later, but with the persistence of the virus in the environment, I probably won't be able to grow this plant again.

[wintergirl]

Originally Posted by Leafmite

It looks VERY suspiciously like virus to me. No wonder he doesn't accept returns....

That's what I thought....

Originally Posted by estación seca

A lot of my neighbors walk through the neighborhood daily. Somebody began throwing cigarette butts in my yard. I still haven't figured out who is doing this. Soon all my Datura showed the yellow mosaic pattern of virus infestation. I had to tear them all out. The virus can be passed through seed. I kept some seed and will try again later, but with the persistence of the virus in the environment, I probably won't be able to grow this plant again.

That is so sad