V I R U S !!!!!! Run for your lives..........

[Leafmite]

The problem with plant viruses is the same as with 'animal' viruses. While some individuals are 'immune' to the effects of the viruses (carriers), others easily succumb. An orchid may carry a certain virus and be fine with it but the commercial tomato/corn/beets/citrus/herb operation next door might be devastated by the virus when some sudden bug infestation infects them with it. It is difficult to eliminate bug infestations in an open environment and food crops bar the use of systemics. Sterilizing hands, equipment while harvesting becomes problematic in many cases (hours, yield=money). Already, viruses are causing loss of yield for many crops in many areas. I don't believe any vendor should be permitted to ship plants that are not virus free. The same goes with bacteria (Greening, Fire Blight), fungus (American Chestnut), or bugs (Japanese Beetles, emerald ash borer, termites, fire ants, etc.). We should do what we can to prevent the spread of problems so a localized problem doesn't become a wide-spread problem. So, these are just my thoughts as a hobby fruit/nut/herb grower and other opinions are great.

[Paul Mc]

Very true. I've read many reports about the devastation of entire crops/harvests due to issues such as you describe.

[Paul Mc]

I'd like to add that I feel that while we may never be able to completely eradicate problems, I do wish on some levels we could work harder to ensure these do not spread per our businesses or handling. I know some will always slip through the cracks, because we can never be perfect, but it would be nice if we worked harder.

However, I believe the flip side of this would be a headache for our beloved vendors. More paperwork, testing and certifications would be required for them. Borders might close up similar to California. Higher regulation would also mean higher cost on a business where only a handful of people within any given nation have an avid interest in keeping or buying these plants.

In some ways, I fear it's a bit of a balancing act on everyone's part to keep everyone happy.

[Rowangreen]

Very true, though I still think that breeding for resistance is not a bad idea. And that includes food crops!

[tucker85]

I lost about 15 orchids to a virus that got into my collection a few years ago. It was before I learned to sterilize my tools. Some of the plants didn't show any signs at first but eventually color break would show up. I'm still finding an occasional plant with it. I always throw them out. I don't like sick looking flowers. The two signs of virus that I've noticed are color break in the flowers (mostly like your C. intermedia) and poor plant vigor (slow growth, not healthy looking).

[Leafmite]

There is much work being done to breed resistance. Genetic engineering is also being done (corn, rice are the ones that make the news but many fruits and veggies are the result of genetic engineering now and the seed companies hold patents). Unfortunately, viruses mutate. Just as a thousand generations hasn't yielded humans immune to the flu for this reason, the same goes for plants. And, genetic engineering is quite expensive, requires time, research and many question whether the certain genes used should be used. Remember, we want crops that provide a high yield, grow quickly, are drought/flood tolerant, resistant to insects, fungus, bacteria, virus, and weedkillers but they must still be full of vitamins, flavor, can't cause health problems/allergies and look as expected. Wow! Yes, you can create plants that resist virus but by continually reintroducing a virus (a mutation will eventually occur) or new viruses, eventually you have plants once again succumbing to virus.
I know this is a bacterial problem but Florida and California are currently trying to prevent the spread of Greening which is really a big problem. Certain plants are unaffected by the bacteria and the transport of these plants is what has been spreading it (along with hitch-hiking leafhoppers that carry the infection).
Much of our fruit, chocolate production, and so much more is in quiet jeopardy. Profits for growers are very low, for the most part. Many growers must get other jobs to pay off debts after a bad harvest and soon are getting out of the trade. Few want all the stress and expense so orchards and farms are sold for other purposes.
Another question: Would people be willing to pay for a guarantee that a plant/orchid is disease-free?

[goodgollymissmolly]

Lots of things have been said here. Unfortunately, Camille's is the most head in the sand. I wouldn't have expected that actually.

To hang your hat on the fact that plant viruses don't spread through the air is pollyana at best. There are several completely ridiculous "ifs" in her statement. For example if your collection is insect free...exactly how does one guarantee that? There are many other ifs she ignored...like if you sanitize your hands between touching each plant, if you never have water splash or drip on an adjacent plant when watering, or never have foliage rub on adjacent plants in the breeze. Unfortunately her position is similar to someone saying you can prevent fires by eliminating ignition sources. You can minimize them but they are infinite and uncontrollable..like lightning, or unanticipated arcs in switches, or static discharges from clothes of different materials rubbing together. You can only totally prevent fire by having no flammable materials or mixtures. You can only prevent virus by not having any in your collection..anything less is minimization, not prevention.

Rowangreen suggests some orchid viruses might come from wild collections. There is an excellent article in the current edition of Phalaenopsis magazine, the Journal of IPA. It is by Erin Wood, graduate Research Assisstant and JE Polston Professor, Dept of Plant Pathology, University of Florida,Gainesville, FL. Every one of you should find a way to get a copy. It's simple, down to earth, and in complete disagreement with most of the statements made here on this thread.

In speaking of ONLY CymMV and ORSV (the two most prevalent in orchids) they say, "CymMV and ORSV are unique in that they enjoy worldwide distribution and have only been found in propagated orchids---never found in wild orchids."

If you only have 6 orchids who the he** cares. You can throw them out and buy 6 more. If you have 2500 orchids like I do with a few really valuable ones, you must test and dispose/isolate infected plants. Anything less is fooling yourself.

As to which orchids get viruses...all of them though in my experience some genera seem more susceptible.

The article above also addresses the issue brought up by someone about asymptomatic plants. The explanation has nothing to do with the plant genetics and everything to do with strain of the virus and the stress endured by the plant.

This a complex subject. I sure am not an expert. Science in general is still learning about these things. That said, some of the stuff I see here is nothing more gut feel science with no effort to get informed.

Thank you.

[Rowangreen]

Actually what it really comes down to is there's too many humans on the world. We wouldn't be pushing food production to it's limits if there weren't ever more mouths to feed. No need for genetic engineering, just breeding what works best, and growing a variety of different crops and breeds, as has been done for thousands of years. It's when we try and 'improve' and get ever higher crops with use of ever more fertilizer etc that we end up with freak plants that die from some silly reason. But with too many people to support from too little land we can't rely on the old varieties of crops.

[Leafmite]

Yes, I agree with overpopulation being a huge problem. But, if you have any interest in botony, genetics, biochemistry, agriculture, public health, or any related field, you soon realize that moving organic beings/substances, living or harvested, to new locations is a huge problem. Scientists can't always predict the effects of a fungus, virus or bacteria, even when they have studied it in depth. One thing we do know for certain is that bacteria and viruses mutate (bacteria share genes with other bacteria, too). This makes them even more unpredictible. In the world, there are still entire populations of plants and creatures that have not yet been exposed to certain viruses, bacteria, fungus, and insects. They will be eventually if we are not careful...will they survive?

[camille1585]

Originally Posted by goodgollymissmolly

Lots of things have been said here. Unfortunately, Camille's is the most head in the sand. I wouldn't have expected that actually.

To hang your hat on the fact that plant viruses don't spread through the air is pollyana at best. There are several completely ridiculous "ifs" in her statement. For example if your collection is insect free...exactly how does one guarantee that? There are many other ifs she ignored...like if you sanitize your hands between touching each plant, if you never have water splash or drip on an adjacent plant when watering, or never have foliage rub on adjacent plants in the breeze. Unfortunately her position is similar to someone saying you can prevent fires by eliminating ignition sources. You can minimize them but they are infinite and uncontrollable..like lightning, or unanticipated arcs in switches, or static discharges from clothes of different materials rubbing together. You can only totally prevent fire by having no flammable materials or mixtures. You can only prevent virus by not having any in your collection..anything less is minimization, not prevention.

I don't have my 'head in the sand' thank you very much, and no need to treat me like an ignorant little child. I didn't say that plant viruses don't spread the air, I said that they don't spread through the air like animal viruses. By that I mean that the particles themselves aren't airborne. The insect vectors, on the other hand, are airborne. The vast majority of viruses depend on insects (or bumbling humans with their tools) for transmission. Obviously that wasn't very clear to you in my first post, I hope that this time you understand.

I was also speaking about indoor orchid growing, where you can much better control what's going on. How do I know that my collection is insect free? Because I check each plant over carefully at watering time. No I can't guarantee there are no bugs, but regular checks keep the likelyhood of it very very low.

Also the risk of spreading virus just by handling plants is low, unless you get infected sap on your hands, and then handle damaged leaves/roots of another plant. Same goes for simply having leaves touching. Research shows that plant viruses can't infect via natural openings (stomata) or intact cuticles. For that reason splashing water also won't infect intact plants. If you want to be picky about it, yes, you could damage the plant with your infected fingernail and infect it that way... Everything I said in my first post is accepted, tried and tested prophylactic measures, for want of a better way to limit virus spread. (other than spending a fortune testing the plants, those test strips are freakin expensive over here)


I am no expert on plant viruses, but I should know what I am talking about after having followed several graduate courses on the subject, though I focused more on the molecular aspects of transmission. If you still think my head is in the sand (which you probably do) I'll gladly indicate scientific literature for you

Personally I think that unless people are growing rare and/or very valuable orchids, we need to chill out a bit about viruses and accept that it's a part of owning plants, or any other living thing. Or you can continue to stress out about it and forget to enjoy the orchids, which is why we have them. Don't get me wrong, I wouldn't like seeing virus in my plants and I'm all for their eradication, but limitation is a far more realistic goal. Eradication in greenhouses is already proving impossible, so those that want eradication also on outdoor plants/crops as well are beyond unrealistic. There have always been plant viruses, and always will be. Breeding longterm virus resistant plants is impossible, the virus will mutate very quickly. Unlike the human flu vaccine which can be changed yearly, the length of the breeding process makes it impossible to be as reactive to changes in plant viruses.