Crown gall is a bacterial disease that causes large, tumor-like swellings (galls) that often occur at the crown of the plant. This 3-page document describes the symptoms and management of this disease on roses. Written by Kamil Duman, Susannah da Silva, Fanny Iriarte, Barron Riddle, Gary Knox, Matthew Orwat, Shawn Steed, E. Vanessa Compoverde, Jeffrey Jones, and Mathews Paret and published by the UF/IFAS Plant Pathology Department, November 2018.
http://edis.ifas.ufl.edu/pp343