Question regarding Procedures for Orchid diseases

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Nelson Wong

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If you suspect there is a virus outbreak in your orchids. What are your procedures?

Because I think I might have either a fungal or viral outbreak in my orchids. It has been isolated to just the lower deck of the orchids and the rest are fine. The suspected infected ones have be separated and isolated.

But what does everyone usually do? Do you bomb it with physan 20 or phyton 27 first? And then wait and see if the orchids improve? If not... then should I just throw them all out because based on reading there is little I could do to save them.


I just think I have an outbreak and it infected about 15+ plants most of cymbidiums and oncidium alliance, a few phals and 2 paphs.
 

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The first thing that you should not do is panic.
I suggest a visit to the Saint Augustine Orchid Societies web page. There, under pests and diseases, you can locate several images and descriptions of various orchid ailments, including virus. Things like virus in a Cymbidium, Cattleya, or Paphiopedilum. See what matches up. They have recommendations for treatment.
Since you can not cure a virus in my mind, why bomb them with anything? you can cause more harm then good. That is the panic I am talking about.
Personally your orchids looked extremely stressed!!! I see oversized pots in some cases. Old decayed media in another. Too much heat. You never mentioned culture, how often do you water? How often do you fertilize? Air movement? etc. etc. etc.
If I were you, I would look to addressing your culture first. Then after a year see if things improve with clean new growths or whatever.
 
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If you have a viral outbreak, throw them away; there is no cure.

That, however, looks to be an extreme acidovorax (pseudomonas) epidemic. Spraying everything - including the growing area - with a Physan solution is the first step, as it will disinfect the surfaces, but it will not do much for the infections within the plants. A copper-based treatment may help that, but as badly infected as they appear, you can probably expect losses.

I agree that they have likely succumbed due to poor culture. If you mist them to raise humidity, stop. It doesn’t appreciably raise humidity, but it does become a great way to spread pathogens.
 
If you have a viral outbreak, throw them away; there is no cure.

That, however, looks to be an extreme acidovorax (pseudomonas) epidemic. Spraying everything - including the growing area - with a Physan solution is the first step, as it will disinfect the surfaces, but it will not do much for the infections within the plants. A copper-based treatment may help that, but as badly infected as they appear, you can probably expect losses.

I agree that they have likely succumbed due to poor culture. If you mist them to raise humidity, stop. It doesn’t appreciably raise humidity, but it does become a great way to spread pathogens.
Thank you for the information. I just disinfected the entire green house - plants, lights, fans, surfaces. The infected plants are isolated and sprayed and left in the corner of the house for quarantine.
I think this only impact the bottom level of the green house because it started there and the fan just expedited their spread. It also doesn't help that the humidity of the bottom shelf was 80% which kept it growing
 
The first thing that you should not do is panic.
I suggest a visit to the Saint Augustine Orchid Societies web page. There, under pests and diseases, you can locate several images and descriptions of various orchid ailments, including virus. Things like virus in a Cymbidium, Cattleya, or Paphiopedilum. See what matches up. They have recommendations for treatment.
Since you can not cure a virus in my mind, why bomb them with anything? you can cause more harm then good. That is the panic I am talking about.
Personally your orchids looked extremely stressed!!! I see oversized pots in some cases. Old decayed media in another. Too much heat. You never mentioned culture, how often do you water? How often do you fertilize? Air movement? etc. etc. etc.
If I were you, I would look to addressing your culture first. Then after a year see if things improve with clean new growths or whatever.
Thank you for the advice. I checked the Saint Augustine orchid web page and some of mine looks like a mixture of bacterial, fungal and virus. I hope it is bacterial and fungal which is treatable.

Some of my orchids were originally larger ones that was potted in correct pots, but it kept dying and I got to busy with work to change them. I also ran out of media recently repotting other orchids and haven't repotted some of them, especially the oncidiums and cymbidiums (I did just order a bunch that should last me for another 2 years). There shouldn't been too much heat since it is in the green house at 75F to 85F. Top shelf is 50% humidity, middle shelf is 50% and bottom shelf is around 60% humidity. I water the them about once week and use slow release 13-13-13 fertilizer and also use 20-20-20 once a month. I have a fan on the top shelf and bottom shelf. I am just happy it stayed isolated to the bottom shelf.

I also recently disinfected the entire green house, lights, fans, everything. Going to repot, spray with physan this weekend and see if they improve. If not, then I will spray with physan again. The orchids that do not improve after 2 months to 3 months, I plan to assume they have a virus and just chuck them.
 
Another thing that you may want to try is to be better at debris removal. Trim off old dead or almost dead leaves. When turning yellow and they are heavily spotted, they are not returning to being green and vigorous. Trim off old dead pseudobulbs. You can dust every cut with plain old cinnamon! Cinnamon is very effective at preventing the spread of diseases and it should be handy and cheap. I use a small child's paintbrush to apply. Good sanitation is important.

I read where you are getting in new potting supplies. That should help. But I also noticed that every type of orchid you have is in the same mix and that might be bad for some of your plants too. Look at the diameter of a Phalaenopsis root, a Cattleya root and an Oncidium root. Oncidium roots are very slender. Oncidiums love moisture. If you pot them using a coarse mix, one with larger pieces, the mix may not hold enough moisture. I noticed years ago that for me, my Oncidiums do much better in a mix of seedling bark @50%, a 20% addition of seedling sized perlite and 20% seedling size charcoal. There is always about 10% of Leca involved. For me when I water every 4-5 days with my Oncidiums, they are never done dry. They are not soggy or wet but certainly not bone dry. In a coarse mix featuring pieces 3/8", 1/2" or more in size dries out way too fast for my conditions. Under those situations my Oncidium bulbs become deeply furrowed or wrinkled. I take that as a sign that they are not getting enough water. They should be really nice and plump!
I also use plastic pots only for them.
DO all of your pots have drainage holes???
 
Another thing that you may want to try is to be better at debris removal. Trim off old dead or almost dead leaves. When turning yellow and they are heavily spotted, they are not returning to being green and vigorous. Trim off old dead pseudobulbs. You can dust every cut with plain old cinnamon! Cinnamon is very effective at preventing the spread of diseases and it should be handy and cheap. I use a small child's paintbrush to apply. Good sanitation is important.

I read where you are getting in new potting supplies. That should help. But I also noticed that every type of orchid you have is in the same mix and that might be bad for some of your plants too. Look at the diameter of a Phalaenopsis root, a Cattleya root and an Oncidium root. Oncidium roots are very slender. Oncidiums love moisture. If you pot them using a coarse mix, one with larger pieces, the mix may not hold enough moisture. I noticed years ago that for me, my Oncidiums do much better in a mix of seedling bark @50%, a 20% addition of seedling sized perlite and 20% seedling size charcoal. There is always about 10% of Leca involved. For me when I water every 4-5 days with my Oncidiums, they are never done dry. They are not soggy or wet but certainly not bone dry. In a coarse mix featuring pieces 3/8", 1/2" or more in size dries out way too fast for my conditions. Under those situations my Oncidium bulbs become deeply furrowed or wrinkled. I take that as a sign that they are not getting enough water. They should be really nice and plump!
I also use plastic pots only for them.
DO all of your pots have drainage holes???
I have been really busy, so I haven't had time to do all the necessary maintenance on all my orchids, I mostly have only been doing maintenance on my prized and favorite ones - the rest kinda got left in the back burner. But I have a 4 day weekend, so I will be repotting and cleaning everything. I do have cinnamon and pure sulfur that I apply when I do trimming, but again. the past year have been crazy busy. So I guess the disease outbreak is a bit of negligence on my part.

I did order 0.3-0.6mm bark, 0.6-0.9mm bark, coarse perlite, medium perlite, 8mm to 14mm charcoal, 8mm to 10mm red lava rock. I also have maybe a scoop or two of 6mm activated carbon, coarse bark, small and large leca, CHC, fine bark chip, that I plan on using up. So hopefully this will give me enough variation to repot everything.

I use 2:1:1:1/4:1/8 small and medium bark chips: medium and coarse perlite: black gold potting soil: char coal: oyster shells for paphs only; it has worked tremendously on paphs.

For cymbidium, zygo and oncidiums, I add an extra scoop of perlite, but I think the media needs to be a bit more course.

For Oncidiums, I use 1.5:1:1:1/4, 0.3 to 0.6mm orchidata bark: medium perlite: Medium charcol: sphagnum. I made the mistake of adding sphagnum moss in the past and retained too much moisture, that's why they perform so poorly and most of my oncidiums keep spider climbing with their new pseudobulb, which I am not very experienced with repotting climbers. So this weekend, I will do a more coarse combination for the oncidiums.

All my pots of drainage holes. I also have a few of my "chinese takeout containers" that I drilled some holes in the bottom and side. I usually use a layer of leca at the bottom, then media for extra aeration.

I think the biggest mistake and lesson I learned is that... always make time to maintain orchids and do regular spray or else disease spread really quickly. I am just happy none of my paphs have been affect. This mostly hit my phals, oncidiums, cymbidiums, and zygos
 
Thank you for the advice. I checked the Saint Augustine orchid web page and some of mine looks like a mixture of bacterial, fungal and virus. I hope it is bacterial and fungal which is treatable.

Some of my orchids were originally larger ones that was potted in correct pots, but it kept dying and I got to busy with work to change them. I also ran out of media recently repotting other orchids and haven't repotted some of them, especially the oncidiums and cymbidiums (I did just order a bunch that should last me for another 2 years). There shouldn't been too much heat since it is in the green house at 75F to 85F. Top shelf is 50% humidity, middle shelf is 50% and bottom shelf is around 60% humidity. I water the them about once week and use slow release 13-13-13 fertilizer and also use 20-20-20 once a month. I have a fan on the top shelf and bottom shelf. I am just happy it stayed isolated to the bottom shelf.

I also recently disinfected the entire green house, lights, fans, everything. Going to repot, spray with physan this weekend and see if they improve. If not, then I will spray with physan again. The orchids that do not improve after 2 months to 3 months, I plan to assume they have a virus and just chuck them.
Why not get some virus tests from Agdia and test a few, rather than guessing because if they are virused in a few months you could spread it to other plants, especially if you are repotting, but even run off spreads virus.
 
Why not get some virus tests from Agdia and test a few, rather than guessing because if they are virused in a few months you could spread it to other plants, especially if you are repotting, but even run off spreads virus.
I am speaking with agdia on quotes for test strips
 
viruses don't spread or show up like that(so many plants got infected all at once). Most likely you might have a mite infestation and this is the result of a secondary infection(bacterial and fungal infection because of the mite damage).
I "would" spray the whole growing area with miticide (not insecticide) besides the treatment for fungal and bacterial.
 

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