Extremely concerning spots on Coelogyne

[BrassavolaStars]

Hello all,

I got these plants off of the raffle table at my society a year ago. They were free so I took them without thinking much.

They were very dehydrated and had some spotting but I was not too concerned at the time as I was still an orchid novice.

At the time, the spots looked like what google images showed as cercospora so I just spayed fungicide and didn’t think on it again until now.

Now that I’m looking at them closely again, I have plumped them up a bit but the spotting has gotten worse and is exceptionally disturbing looking.

They have bloomed before without any issues/streaking but the look of these spots is bothering me.

I am especially concerned about these plants being in the greenhouse for a year and sitting next to other plants, especially since there is now a mite problem. It looks viral to me and I’m worried either close proximity to other plants or mites could have spread it all over the greenhouse.

[BrassavolaStars]

Another thing I forgot to mention is that it is especially bad on the underside of the leaves and isn’t showing up as much on the top side of the leaves.

[estación seca]

Coelogynes should enjoy Michigan summers outdoors far more than in a greenhouse. I would get it out of the greenhouse.

I don't know whether it's a fungal infestation, fungi attacking already dying tissue or a viral problem Take a leaf to your local agricultural extension office. Or send photos to the Michigan State horticulture department for help with an ID. They have an extensive orchid collection.

Any given fungicide will not be effective against all kinds of fungi. Almost all fungi are resistant to one or more fungicides. Before using chemicals to treat diseases be sure you know what the disease is, and that it is susceptible to the chemical you are using. Otherwise you will also kill beneficial fungi and bacteria that help control harmful fungi. And you may promote resistance to the chemical in other organisms.

[WaterWitchin]

So darned nice to have ya back ES.

[SouthPark]

Brassa ----- what sort/brand/type fungicide did you use? Probably have to try various kinds ----- do some rotation of fungicides. Hopefully at least one will be a key and sort that one out.

In lots of cases, some gentle air-movement in the growing area can cut down or even prevent this kind of thing.

So if there are any possible things on the check-list missed out ------ involving temperature, light levels, air-movement, watering schedule, state of roots/media etc, then go through the list. Because normally - if all the conditions are good, the chance of seeing this sort of thing becomes slim, or even no chance.

[Roberta]

Originally Posted by SouthPark

Brassa ----- what sort/brand/type fungicide did you use? Probably have to try various kinds ----- do some rotation of fungicides. Hopefully at least one will be a key and sort that one out.

That is assuming that is a fungus, not a bacteria or virus. To determine a treatment, a diagnosis is needed. (In the case of virus, there is no treatment) The advice from ES is spot on - get it tested.

[SouthPark]

Roberta ----- testing would certainly sort it -- as in identifying. So if paying for testing is an option and ok, then by all means ----- a very good choice.

Or, if we happen to have on hand a few treatments - assuming fungus etc, and try it out ------ and the situation improves, or even disappears --- then that's another option.

If no treatment on hand works ------ then maybe virus. And testing could remain as an option.

[BrassavolaStars]

Hello all,

I had tried Cleary’s and Physan on it over the course of several months but not too recently.

I’m sure at some point it also had been exposed to copper or Aliette indirectly but I don’t remember.

I’ve seen similar spotting that was suggested as being either Orchid Fleck Virus or ORSV which is what is concerning me.

I wouldn’t be as worried about viruses if it wasn’t like this when I first received it. In other words, It had these spots when I got it so I can’t really say if it has anything to do with my conditions.

I have never used cutting tools on these plants, but I’m sure I’ve had water drip from these plants on to others along with possible mites biting these plants and then others. I am worried that if it is a virus, it has spread to many other plants by mite or water.

Is there a test that also checks for Orchid Fleck along with CymMV and ORSV?

[SouthPark]

Brassa ... in Australia, I notice sites like these online ..... Click Here, which mentions services for testing "OFV".

Pretty sure you will have similar services over there.

[MJG]

Look into Critter Creek. I know they do testing for cymv and orsv. I haven't looked into what other testing they do. Their website will give you an idea of tests available and cost.

I routinely test my incoming orchids for cymv and orsv, so I purchase and use Agdia's test kits. The kit I use doesn't test for ofv.

If it were my orchid, I'd want to know if it had a virus even though it's not treatable. If it were a virus, I would get rid of the plant and I'd also know to watch other plants for symptoms.