Crown gall

Crown Gall is a type of plant disease caused by the bacterium Agrobacterium tumefaciens. This disease is characterized by the formation of galls or tumor-like growths on the crown of the plant, typically at the junction of the root and stem. Crown gall can affect a wide range of dicotyledonous (broad-leaved) plants, and is particularly common in fruit trees, roses, and woody ornamentals.

Causes

The primary cause of crown gall is the bacterium Agrobacterium tumefaciens. This bacterium is soil-borne and can survive in the soil for several years. It enters the plant through wounds, which can be caused by pruning, grafting, or damage from cultivation or insects. Once inside the plant, the bacterium inserts a piece of its own DNA into the plant's cells, causing them to proliferate and form a gall.

Symptoms

The most obvious symptom of crown gall is the presence of galls or tumor-like growths on the plant. These galls can vary in size from small nodules to large, woody tumors. They are initially light in color and soft in texture, but as they age, they become dark and hard. Other symptoms can include stunted growth, reduced vigor, and in severe cases, death of the plant.

Management

Management of crown gall involves a combination of cultural practices and chemical treatments. Cultural practices include avoiding injury to the plant, removing and destroying infected plants, and maintaining good soil health. Chemical treatments can include the use of bactericides or biological control agents. However, these treatments are not always effective, and prevention is the best method of control.

See also

• Plant pathology
• Agrobacterium tumefaciens
• Gall