Strange Oncidium yellow black spots on leaves issue

[braxtonds]

For me, last year was pest issues, this year are leaves issues. Sorry picture heavy post incoming.

It's time for me to begin to make room in the next few weeks to bring all my orchids back inside for the winter. This year I've expanded my collection to include many different types that I've never grown before oncidiums and their hybrids. These soft leaved types are bringing me issues that I need help on.

This is probably my worst offender. I began seeing these spots all over the new growth and they are driving me insane. I've tried Physan but I have to admit that I do not know many of the signs of bacterial or fungal infections and have been searching the forums for help.







These are photos from 3 different plants, all next to each other, all with the same issue. They all receive similar light, which is fairly high, full to dappled light till around 2pm. It is affecting only the new growth leaves, the older leaves are fine.

I need help to identify if its too high light, or a fungal/bacterial issue. It was also suggested by a friend that it might be a fertilizing issue. I normally use time released fertilizer to ease my watering regimen. But this year I used a different brand than I normally used to, Osmocote, 19-6-12. I used it mainly because I was given a large amount of it, should I get something else? Or did I put too much in the mix?

Also, these spots showed up on my C. Green Emerald 'Queen' sitting right next to these plants. Is this related? I fear I might have a serious cross contamination issue and would love some expert advice. Thanks!

[cattspeciescollector]

I have some similar spots on my cattleyas. See the post with pictures that is labeled "black spots or pigmentation". Are the spots reddish? If so they may be natural pigmentation differences? I have also heard that is pretty common to get water spots with oncidium alliance plants because the leaves are super thin and prone to discoloration. Are the spots caved in or rounded? That is one thing I used to distinguish the cause of some of the spots I have, if they are rounded or sunken than might mean an actual infection just like humans can get deep sores or inflammed round spots.

However... disclaimed... I am no expert, but I like to hear everyone's experiences so I offer mine and I hope some more people comment here.

[NYCorchidman]

Cattleya first. They look like pigmentation to me.
You can give slightly less light if you rather not see those spots, but they are benign.

Oncidium hybrids, those are disease spots.
Oncidiums are very very susceptible to leave spottings and I do not know why.
I love oncidiums for colorful flowers and ease of growing, but almost all of them except for very few had these spotting issues, and they drove me insane as well. I'm a clean freak. lol
So I no longer grow oncidiums other than cheap supermarket bargain with great quality flowers.
I keep these for flowers and then toss or give away.

I just bought oncidium Twinkle in bud.
It had a few spotted leaves which I immediately trimmed off and now everything is clean green.

If those spots appear again, I might freak out and toss. lol

Sorry I'm not much of help, but other members who like oncidiums seem to just accept the spotting as "oncidium" thing.
I just can't get over it.

The common but very popular and beautiful oncidium hybrid with no spotting ever is the good ol yellow dancing lady. There are a few varieties and I have never had any spotting issues with those.

Certain miltonidium, brassia and brassia oncidium hybrids are generally spot free as well, so try and look for those for alternative options if you like starry shaped oncidiums.

[braxtonds]

That does actually help. I was just concerned that the plant was infected with something, but, if it's more of an unavoidable thing then I am more likely able to live with it. I am also a neat freak and love all my leaves nice and green. I was just concerned about trading plants with spots, I didn't want to pass anything along.

[NYCorchidman]

The funny thing is the plants still seem to grow and flower fine.

Maybe it's something that only oncidiums get.
I don't know.
but I don't like how they look with spots, so I'm done with them. haha

[tarev]

My Oncs are terrible with their spots too..I just try to ignore them, unless it is spreading like crazy of course..but so far it just goes like that. One is doing a spike this Fall, and some actively growing new pbs too..so I guess it is just like that.

I am just waiting for the Onc to drop that leaf..it does it on its own anyways later on. If I remove all the leaves with a spot..I will not be left with anything!

[NYCorchidman]

I bought this small oncidium hybrid with amazing spicy sweet fragrance from a show three years ago.
It had dark marks on all the leaves. I say mark because it was not those common tiny circular spots, but rather very thin skinny lines that were scattered all over the leaves.
It grew well and the new growth will be clean green for a while then get covered with those little line-like marks. I thought virus more than anything and wanted to test it but never did.
It grew fine and flowered twice each year I had it.
It smelled wonderful and looked so nice, well, other than the leaves.
Each growth got slightly bigger as well and the flowering was better each time.
So apparently it was doing very well.
Then earlier this year, even the newest growth had all its leaves back and front and everything covered with the marks.
I just felt so bothered everytime I looked at the plant.
So after the flowers fell, I just threw it away.

I posted about spottings and other issues on oncidiums a few times here, but the answer is basically always "oh, it's just oncidium thing".

Well, I can never get over it. It's sad because they are easy grower and bloomer, and many are very pretty in bloom.

Oh, well...