What is it and how to stop this disease?
 

Hello all. Haven't been on here for quite some time. In the past year I have rehomed 80% of my orchids. I do have nine left and of the nine there is a disease spreading rather rapidly through the collection. Hopefully these pictures will post and I will get some responses. They are in orchidia in an East window. They bloom reliably and other than these leaves with these pitted Brown markings, they all appear to be in good health. Help!

I suspect a bacterial or fungal infection, and can recommend two potential paths to take:

Inorganic chemical: Phyton 27, a copper sulfate treatment. Do not use on dendrobiums or thin-leaved species

Probiotic: Concentric Ag Garden Solution, which contains consortia of beneficial bacteria and fungi that kill pathogens and generally improve plant growth.

Thank you Ray. Which do you think is best of those two?

They are both fine, but ever since I was given samples of the Garden Solution product and tried it, I am convinced it is the way to go for me - and is the reason I sell it. (That, and they asked me to...)

It is marketed as a probiotic, meaning that it protects your plants from diseases (which it does) and fortifies them, but it can also be used as a curative:

Mix 5 tablespoons in a gallon of water and immerse the entire plant for a few hours, if you can easily do so. If not, saturate the potting medium and spray the plant, wetting all surfaces. Spray it 2-3 times a day, and the rot should stop progressing in a few days.

The normal application is 3 tablespoons/gallon, applied with regular watering once a month.

Will do. And thanks again