Virus... to test or not to test?

[MateoinLosAngeles]

This month's AOS' Orchids magazine features an article by Sue Bottom in which a quick tour of her greenhouse with Dave Off (Waldor Orchids), to identify potentially virused orchids, turns into an orchid massacre.

This got me thinking... is it worth it? Should one test every orchid they receive and go through refunds and exchanges of virused orchids... if so... how many nurseries are really virus free anyway? And what's the worst that can happen? Shouldn't a vigorous plant be able to overcome infection?

Regarding ethics, I would never sell or gift a virused plant. But... for a private collection (of, yeah, a few dozen orchids), is it really worth it?

[dbarron]

IMO, unless you're disseminating plant material, it probably doesn't matter that much. We all want virus free plants, but most living things are full of parasites, it's life.
I know of an extensive commercial plant collection that is (rumored) to be extremely virii filed. While by my own thoughts it doesn't make much difference, I've shied from ordering from there (so maybe it makes a little difference).

[Ray]

As I’ve stated many times, I believe that plants, like humans, carry every pathogen they have been exposed to, but that, unless an additional stress is plced on them, they can live on fine without issue. The corollary to that being that I doubt there is such a thing as a virus-free plant. “Undetectable”, sure. “Totally free of virus”, naaahhhh. That does not mean we should ignore them.

At this point, we are all carrying a strain or two of the coronavirus. That does not mean we will contaminate others on the bus. Display symptoms, on the other hand, and your viral loading has exploded, making the spread far more likely. Might it not be that way with plant pathogens, as well?

Back when I was selling plants, I purchased-for-resale a bunch of really spectacular Oncidiinae clones from a well-known commercial grower in Hawaii. A customer of mine tested and found it virused.

I contacted the vendor and they immediately refunded my money, as I did for anyone who got one through me, and destroyed the plants. The vendor, however, continued listing the plant. When I asked about that, the response was “most of them will just be sold locally to folks who will tie them to their fences.”

That seemed might irresponsible tome, so I stopped buying from them.

[sam1147]

There are only 2 viruses today that we can identify ourselves with kits- -Cym MV & ORSV .I do NOT agree with Ray. Plant either got them or is free of them. If a planet is infected it can contaminate your whole orchids population.
For me main question is 'how old/dear/expensive/replaceable' are your plants. Are you ready to invest 5-10$ for testing each one of them ?
By the way -I buy 75% of my orchids from Dave. I think that he checks most of his valuable plants.

[Clawhammer]

I don't worry about viruses in my orchid collection and I don't think it is worth testing a personal collection, but different strokes for different folks. I agree with Ray that most plants have some type of virus, and most all viruses that affect plants will be dormant if the plant is having its needs met. I have a fig collection and many people are worried about FMV, but as soon as the plants are mature FMV goes dormant and no longer effects the plant.

I grow in my basement and don't really have vectors / practice good greenhouse hygiene, so not too worried about spread.

I have not seen a single person on this board or in the FB groups I am in lose a collection to a virus. I would only think about this topic if I ran a commercial operation.

[Dimples]

As a hobby grower that isn’t shelling out big bucks for any one plant, and isn’t collecting any hard to get plants, I don’t bother testing. I use good hygiene and sanitation practices to minimize transmission potential. But, if someone offered me a free plant that had tested positive for a virus I’d probably decline. I’d maybe take it if it could grow outside year round, but only if I liked it quite a bit.

[sam1147]

Originally Posted by Dimples

As a hobby grower that isn’t shelling out big bucks for any one plant, and isn’t collecting any hard to get plants, I don’t bother testing. I use good hygiene and sanitation practices to minimize transmission potential. But, if someone offered me a free plant that had tested positive for a virus I’d probably decline. I’d maybe take it if it could grow outside year round, but only if I liked it quite a bit.

Why would you decline ?? Seems like you have "good hygiene and sanitation practices" In any case your collection does not include "big buck" or "hard to get plants" ,so why not add a nice free plant to the collection ?

[Dimples]

Having good hygiene practices doesn’t mean I want to intentionally bring in plants with viruses. I can’t easily know if a plant I’m buying is virus-free before I buy it, so I take necessary precautions to account for that risk (buy from quality vendors, minimize contamination, etc.). If I know a plant has a virus, I can very easily avoid the known risk.

[Keysguy]

I believe a commercial seller should test every plant.

Do I test mine? No way. I don't sell plants commercially and if someone asks for a division of one of mine and asks if it's been tested I respond "nope, take it or leave it"

That being said, I've been known to sacrifice a couple of plants that looked wrong to me.

[MateoinLosAngeles]

I'm with Ray here. The core issue is that there are more unknowns than knowns. For example, in terms of undetectable levels of a virus. A person with HIV who takes their medication as prescribed might keep their infection undetectable and untransmittable and live a long and otherwise healthy life. On the other hand, a person not receiving such treatment may develop AIDS within a couple of years and pass away shortly after. Extreme opposite outcomes. The key here is that to keep HIV at bay or other viruses such as Hepatitis C, medication is needed as our immune system does not protect us from them.

On the other hand, less pathogenic viruses, such as the flu, seasonal coronaviruses, or the omnipresent coronavirus causing Covid-19, can be fought by our immune systems.

The question is whether the viruses infect orchids more like HIV or the Flu... And how are they transmitted? Carried in shared water? Proximity?

And can we pump their immune systems by providing the appropriate light, temperature, nutrition, and microbiological support?

It's fair to try to control your collection so as to not be suddenly forced to throw away 20 years of work. But isn't that why we generally stretch ourselves by buying more orchids? Because we accept that a good bunch of those will die and that space will be freed up.

Maybe the solution should be to have plants in "islands" instead of growing together and having an island for the "sus" plants... But by the time they're sus... would that be too late? Who knows.