Diagnosing white nodules on plant stem

Question

I'm writing to ask what these are. Help appreciated. (It turns out to be very difficult to search for this particular affliction online!)

Answer 1

This is scale - possibly cottony cushion scale (Icerya purchasi).

On your photo you can see the insects in various larval stages and the adults with the white egg sacs, that can contain hundreds of eggs. What can also be seen are the clear to milky droplets of honeydew, i.e. the excreted liquid from the plant sap that the insects were drinking.

I recommend you start looking into treatment options soon, before they severely damage your plant or spread to other plants. (This kind of scale is not very selective when it comes to food plants.) The scale actually somewhat protects them from insecticides and not all types will work. I personally prefer systemic insecticides over sprays for scale because the insects will absorb it through the plant sap, but that is only an option for decorative plants, not food crops. Alternatively, beneficial insects like cardinal beetles or parasitic flies have been used successfully.