bacterial diseases, group of grapevine diseases caused by bacteria, small organisms which do not commonly attack vines but which can be deadly and are difficult to control. Of the bacterial diseases, pierce’s disease is the most important and quarantine authorities around the world are anxious to stop it spreading from America. In parts of North and Central America (southern California, Florida, and eastern Texas, for instance), viticulture can be rendered commercially impossible by the natural presence of this disease. Other economically important bacterial diseases are bacterial blight and crown gall.
