Black/Yellow Spots on Oncidium Leaves
 

Afternoon, all! Long time no speak. :) My orchids have been happy and well.

I recently purchased on Oncidium Twinkle Pink Profusion online and today it arrived. I am concerned about some black/yellow spots, and some yellowing I see on its leaves. I am wondering if it's something I can treat, or if I need to send it back?

I have attached pictures. I figured from some research that the black/yellow spots are probably some sort of fungi, which I've read can be pretty common with some oncidium types. What I'm not sure about is the bright yellow you see on the one leaf in particular. I'm not sure if that's a virus or what that is. I also think he's a wee bit overpotted, if he's anything like the oncidium I've got downstairs (which is gigantic and loves being squeezed into its pot. It currently has 12 flowers on it, so I'm sure it's happy).

In the mean time, this little guy is quarantined from everyone else. I'd like to get him sorted out if I can, as he's a nice looking little plant otherwise.

Thanks in advance for any help!

I make a concoction of:

15 drops dish soap
1/4 tablespoon cinnamon extract (the one you find in the spice or baking aisle of the supermarket)
2 cups tepid water

shake it well in a sprayer and make sure everything gets wet including nooks and crannies.
make another batch and soak the pot for 5 min....
repeat next week

this kind of plant is prone to fungi infestation since the leaves are thin and bugs sucking on the sap leave saliva that attracts fungi to develop.

*this concoction also can kill bugs from mosquitos to flies...to cockroaches

it is also an antiseptic so you can use it to heal open cuts on the plant...

a friend of mine used it for his athletes foot fungi infestation since it is an organic home remedy

Thanks, Bud! Is the yellowing on that one leaf something different, or would that be fungus related too?

Sorry, I can't say what this is or isn't. I'm chiming in just to say that I've seen very similar if not the same on a couple of my Oncids. They were all treated for other, mostly preventative means, a couple weeks ago with Physan 20 and I've seen no change. But they've also had for a while and the plants seem to be alright.

That said I'm not the most experienced, let's just say I'm giving you moral support! Going to hold on to the recipe from Bud though and pay attention to this thread. I remember someone listing it before and I lost the thread so thanks Bud! Very happy to have it now and something that's harmless to use indoors now that it's cold and all plants are in.

It looks like a reasonably healthy plant to me. Oncidium leaves get spots so easily that it is very common. The bit of yellowing could be attributed to a change in light intensity. I would just keep it apart from other plants for a while, which I do with all new orchids. Keep an eye on it and it will likely be fine. I don't think it looks terribly over potted.

You could use Bud's recipe on the leaves as a precaution or spray Physan occasionally to prevent bacterial and fungal problems. I would not use cinnamon powder or oil on roots as it can desiccate them.