Crown gall

Crown gall is a bacterial plant disease with a very wide host range. The bacteria enter through wounds and live between cells, which they stimulate to grow, producing the characteristic knobbly growth. Eventually the gall may hinder the transmission of water and food supplies, and the plants may wilt and die.

The disease occurs widely throughout the world on such economically important plants as apple, peach, pear, raspberry, rose and sugarbeet.