Seasonal development
and life cycle—Crown gall
Crown gall is caused by the soil-inhabiting bacterium Agrobacterium tumefaciens. This organism
can survive in the soil for at least 2 years in the absence of host tissue or for several years in decomposing
crown gall tissue. Bacteria are released into the soil when galls are wet or when older gall tissue disintegrates.
Seedlings may also be affected by the bacterium during germination; established trees and vines are infected
only through fresh wounds such as those caused by growth cracks, pruning, damage by cultivation equipment,
or freeze injury. | 
Bacteria
survive in undifferentiated tissue |
