Any help would be appreciated. I can't figure out what these white "growths" on my tomato stems are.

More information:

* Palm Desert so it's very hot/desert climate. Almost no "tomato" bugs like caterpillars. We have tons of ants and some flying insects but that's about it.
* Two plants have them and the rest don't.
* Plants are in containers.
* The white "growths" are on random spots on the stems all the way from the bottom to the thin stems at the top.
* Funny thing is the plant doesn't seem to be too affected by them... YET... they are rapidly multiplying so I'm sure they might affect the plants at some point.
* They do NOT look like mold. They look almost like insect cocoons to be honest but I don't think they are.
* Size varies but MUCH larger than powdery mildew meaning they are from 2-3 millimeters to almost the size of a dime but not round more oblong shape.
* There are 2-4 more popping up every single day.
* They seem to be "on" the stem vs burrowing in or growing out of the stem as a normal fungus or disease would.
* Leaves not affected as far as I can tell.
* Plants get plenty of water, etc etc and are healthy with many tomatoes growing or let's say as healthy as they can be when it's routinely above 105 degrees.

Picture attached and I played with the image to highlight the growths.

COMPLETELY stumped as to what they are.

Again ANY help and advice greatly appreciated.