Black spots on Oncidium

[mstlindsay]

I just bought this orchid last week from a reputable grower and it now has big black spots on the leaves. Can anyone tell me what type of disease this is and how to treat it? Pictures attached. Any advice would be appreciated. Thanks very much.

[chapala]

Might it be sun scorching? Looks like the leaves may have burned from some direct sun. If not that, I'm not sure.
Reta

[pikespeak62]

Looks like sunburn to me too

[atcrosby]

It definitely looks like sun scorching. The orchid is getting too much light.

My experience with black spots is that some orchids will have black spots on their leaves (freckles) but these do not grow in size.

If it's a fungal or bacterial blackspot, you'll see a yellow ring around the black spot and it'll grow larger across the leaf. To prevent this from happening, your orchid needs good air circulation plus never water in the late afternoon when the plant doesn't have a chance to dry before it gets cooler allowing the fungus to start.

Hope that helps.

[Cynthia, Prescott, AZ]

Definitely sun burn. This plant appears to have enough leaves, so if you want, you can cut off the leaves just back of the burn, unless you have burned more leaves since the picture. Please use a sterilized tool to cut into live tissue, and don't use alcohol for sterilizing. It does not kill virus, but preserves it in an infectious state.

[mstlindsay]

Thanks everyone. I guess just that one day I put it outside in this Florida sunshine did the job. The roots look good though. Thanks for all your help.