I think that may not be the case, there is a lot of connective tissue between these blisters, as if it's some kind of result of fungus or some other thing. I'm also not sure whether to leave it or to brush as much of it off as I can.

Old scale?

Old scale was my second thought

Would a dormant oil spray help?

I'll try to get a better picture, it could be old scale. The best way to describe it is that it looks like the stems have been fried and have blistered all the way up and down. I think it came on pretty quickly, as well, in the summer. At first I thought maybe the neem oil I use had somehow caught the sun rays and cooked the stems, but I don't apply that much for the stems to get soaked.

Is the cane alive? Do the scabby parts wipe/rub off? I agree with Jared, could be old scale damage.

Moses

Where are you located.... I am in So Florida and I get that too..... not sure what it is....

Moses, it is alive and the scabby parts rub off very easily, they just flake off like dust. Sharon, I'm near Los Angeles, so we've had some hot/dry summers lately.