do you worry about virus?

[Sekhmet121]

I use alcohol on my tools also. I hope that's enough of a preventive method. I do bleach my pots though and water by flooding my guys one at a time in the kitchen sink under the tap. I figured that was a better way then the dunk method.

[Leafmite]

I take the chance of reusing water as, with the water softener, I have to collect rain water or buy distilled water. With any new plants or plants I have separated, I water them last or with different water.

[Tim P.]

Unfortunately I'm in the same boat as leafmite. There is water softening in my building. I can't just run them under my shower and I don't have access to good water except for what I bring from home

[AnonYMouse]

There are people who will vilify you as a typhoid Mary. The reality is, these are your plants, you grow them as you see fit. If you trade/sell/gift them, just be honest.

I haven't resorted to dunking in the same water yet but this drought has me feeling guilty not capturing pot run-off.

[Orchid Whisperer]

Like many other things, plant hygiene can be a to-each-their-own sort of thing. Different people have different levels of "fussing" that they are willing to go through with their plants. I think I am more tolerant of a higher level of fussing, in part because I have some plants that are quite old (at least to me) and I don't want to risk losing them.

I would add that Physan, alcohol, etc. will probably take care of many problems, such as fungi or bacteria, but will not kill viruses. For that, you need something that will destroy viruses chemically (like bleach), or you will need heat, often much hotter than boiling.

[samarak]

This is a complex topic. It comes up regularly with other things I grow, too (certain bulbs), and there's a lot of FUD (fear, uncertainty, and doubt) as well as misinformation around, and there's a lot none of us know.

One of our mentors, who was a breeder and had thousands of plants in his greenhouse, didn't use pruners or scissors at all. He bought boxes of cheap, single-edged razor blades. One plant, one razor blade, then straight into the trash. It eliminated the issue of decontaminating pruners entirely.

We work hard at practicing good hygiene, but we don't go that far (yet). Most of our collection is species, and odd ones at that, which we've grown from seedlings, so we're starting with a fairly low risk level.

We have recently sort of inherited some plants, including some older Cattleya-alliance clones, from another grower, and although I don't fully trust the virus-detection strips (because I can't get the data I need to know what trust level is justified), I did buy them and test all of those older plants.

Disinfecting tools. Here's one of the places where there are a lot of very strong and conflicting opinions. I'm just going to say what I think and people can agree or disagree as they wish.

I looked at tobacco mosaic virus (TMV) - it's almost certainly the most studied plant virus there is, and probably by a wide margin. It's also one of the toughest plant viruses, in terms of how long it can remain active in soil or debris and in its heat stability. So if something will kill TMV, I choose to have a high level of confidence that it will also kill orchid viruses. And since TMV is so important economically, people have spent a lot of time looking at what will kill it (by comparison there's much less work on orchid viruses).

Physan - and other quaternary ammonium salt preparations - are routinely used for virus control (among other things), and Physan has been found to be effective in controlling TMV. So we keep Physan around and we use it for tools. We leave tools in it much longer than should be necessary between uses.

Heat denatures proteins and there's no question it will kill viruses. The question is how much for how long, and there is a wide range of reports. Most that I found suggest that TMV, which is one of the most thermally stable plant viruses, starts to degrade at around 50-60 C and that boiling water is more than sufficient.

I found one report that seems to have some credibility which said that trisodium phosphate (TSP), was not effective against TMV, but that a *fresh* (not more than 2 hours old) 1:10 dilution of household bleach was effective. Several reports I read suggest that household alcohols are not effective against TMV - doesn't mean they aren't against other, not-as-tough plant viruses, but we don't trust it.

A long reply. Hope something in it is useful.

Steve

[lotis146]

What are the most common signs of viruses? I know this is a very generalized question but I'm curious.

Thank you!

[Cym Ladye]

Originally Posted by lotis146

What are the most common signs of viruses? I know this is a very generalized question but I'm curious.

Thank you!

I am a great advocate of asking questions of Google. Try this site for photos of various viruses in various orchid plants: Images of Virus on Orchids

I found several other references too as well as lots of other images.

CL

[tucker85]

I don't worry about virus. I was in the medical field and we always used universal precautions. That means we treated every patient as if they had a contagious, incurable virus. A few years ago I had a couple orchids with virus and I managed to spread it to several other orchids. Now that I sterilize my cutting tools between plants (universal precaution), I never have a virus spread, although I do know it's possible for insects to spread it. If I see something unusual I'll keep my eye on that plant to see if there's color break or some other indication. By the way, phalanopsis can have virus and you'll never even know it because there's seldom any symptoms in phals.

[quiltergal]

Some orchids will never show symptoms of having a virus.