Excuse me, teacher, how to return the white roots on the tomato stems?

Just look at the adventitious roots and you can't judge that it is a bacterial ulcer. High soil and air humidity and poor root development may cause adventitious roots.

Bacterial canker, bacterial wilt, etc. can cause symptoms of adventitious roots, and generally leaves wither at noon.

So only one symptom of adventitious roots can't be sure to be a disease. It should be comprehensively analyzed and judged.