DISEASE
 
   NAME
     Crown Gall
     Agrobacterium and other species

Description
Bacterial problem that is associated with wounds, caused by insects or physical damage in plant tissues.

Symptoms 
Soft galls appear on the roots, base and up the stem becoming hard with age. The plant responds by loosing vigour and may produce less flowers or fruit.

Source and Dispersal
The spores are found in the soil or are released from decaying galls and are spread by infested soil or plant material and contaminated tools.

Favoured Conditions
Continuous cultivation of infested plants allowing a build up of spores in the soil and poor propagation methods during grafting or handling transmits the disease.
	
Affected Plants
There are many species of woody plants that are affected these include, species in the Rosaceae family, Dahlias, Geraniums, Vitis and Brachychiton species. 

Araucaria, Arbutus, Begonia, Chaenomeles, Corylus, Euonymus, Euphorbia, Leucanthemum, Protasparagus, Thunbergia and Wisteria species are infected by a simular crown-gall (Erwinia tumefaciens) which causes smooth swellings to appear on the roots and main stems of the host.

Large cactus species are attacked by the Crown Gall (Agrobacterium tumefaciens). It develops galls on segments and roots with some of the aerial galls attaining a diameter of over 600 mm.  Root galls, become a spongy and may attain a diameter of 300 mm. Galls on aerial parts may be cut from the plant with some success. Control methods include not damaging the plant surface and any bacteria contaminated soil should not be used for propagation.

Sorbus aucuparia is seriously affected by this disease.

Non-chemical Control 
Remove and destroy any infected plants and avoid replanting in the same area with susceptible species. Care should also be taken when selecting new plants that they are not infected, look for lumps at the base of the plant. Disinfect pruning or grafting tools to inhibit transmitting the disease.
A treatment of control is to dip seeds, cuttings and seedlings into a solution of a non-pathogenic strain of bacteria such as Agrobacterium rhizogenes before planting. This is commercially available under several brand names.

Chemical Control
There is no chemical control of this bacterial problem.
Note
Always read the label for registration details and direction of use prior to application of any chemicals.