Freckles or cercosporia

[SteveM]

Hey All,

I appreciate all your help as usual. I have a encyclia Cordeira that is showing round purplish-brown spots. It has been in a greenhouse which has been in the 90's during the day and upper 60's at night. I do have several fans going all the time and this is the only plant that I have showing any symptoms (have like 20 other orchids, Christmas cactus and aloe plant, It is also on a new sheath and I don't see any anywhere else on the plant. I am hoping this is "freckles" but I am leaning more towards cercosporin. I do have it in full sun 4 hrs a day under 40% shade cloth with bright light the rest of the time. I have sprayed with a copper fulgide as well as the other orchids in there, Dendrobium I sprayed with Tebuconazole. Any other ideas or how to go around treating this. I really hate to take off that new sheath. I have posted a picture. Thanks all greatly appreciated.

[Roberta]

Photo is too small to see anything. I think that with all the treatment you have already done, now is the time for watchful waiting. The spot isn't gong to go away. But you can watch it to see that it doesn't get larger. You could make a circle around the spot with a Sharpie. Then it will be easier to detect changes.

[SteveM]

Sorry about picture. Thanks for your advice. You are always a big help.

[SteveM]

Ok I really think this is cercospora. The blemishes seem to have gotten slightly better with 1 copper treatment, Not getting any bigger anyways, I have had the same looking thing on a Phal last winter which took the stem in a matter of a week or 2 from one tiny dot. Back then I tried to stay away from fungicides, I have had bad luck with copper in the past with tomato plants and toxicity and honestly have been afraid to use it, The only other fungicide I had at the time was daconil which is only a preventive and not very effective once a fungi takes hold (atleast from my limited experience gardening for 20ish years). I tried peroxide and cinnamon last winter with the phal and it just laughed at me. I think I am in for a long battle here. Juat sitting back and being patient. Thank god all other plants dont show that yet.

[estación seca]

What were your winter temperatures when the Phal. ran into trouble? What is the relative humidity in your greenhouse?

[SteveM]

Phal was inside. 68 most of the time 65 the low. Humidity 30 ish percent. I tend to under water Phals. I think Im seeing some new spots by thGoing to give it 1 more day although Im worried it will be consumed over night. I do have atleast 1 fan going in greenhouse all the time...if not 2...may turn them on high to get more breeze at night. Greenhouse condition now has been low 70s upper 60s at night.... upper 90s during the day...night humidity is around 80 percent daytime in greenhouse like 50....not too far off from the outside humidity... I have all windows and doors open..with fans going