Identify rough, brown patches
 

Several of my older vandals have developed the rough, raised brown patches. The leaves eventually yellow & fall off. Does anyone have a diagnosis & treatment. Or is it just normal aging of the plant? Thanks

I can't see well enough to be identify the problem, but that is not normal. It could be a patch of mealy bug or scale insects. Are you growing this indoors now, or outside? There are a number of diseases that can cause this. Go to the Web site of the St Augustine Orchid Society and look at the section on pests and diseases.