The AWRI helpdesk has received reports of crown gall-like symptoms affecting young vines in several regions in Australia in recent months.
The reported symptoms are gall formation at wound sites, stunted growth, peeling and cracking of bark, as well as a gradual decline in vine vigour and vine loss due to girdling as the disease progresses. Young vines are particularly vulnerable as galls can impede water and nutrient flow throughout the vine.
Response
An industry response group has been convened to coordinate the response to this issue. The group includes representatives from AWRI, Australian Grape & Wine, Wine Australia, Vinehealth Australia, the Vine Industry Nursery Association (VINA), the South Australian Vine Improvement Association (SAVIA), State Government departments, and diagnostic laboratories, and is developing eight project areas where work is needed to better understand and respond to this situation.
These project areas are:
- Data and information collection and analysis
- Communication to industry
- Pathogen identification
- Diagnostic protocols
- Identification of source
- Nursery disinfestation procedures
- Farm-gate hygiene procedures
- Biological control
Read the AWRI’s recent crown gall-like e-bulletin for further information about the project work.
Reporting
A form for growers to record cases of gall-like symptoms is now live, to support the collection of a comprehensive data set describing the extent of this problem across Australia. All growers who have observed gall-like symptoms are encouraged to report them using this form. A collation of all reports significantly assists the response, allowing links to be identified between any of the observed incidents, and for gaining an understanding of the breadth of the issue. Note: information reported may be shared with the task force, but will not be revealed publicly or shared outside this group.
If you see gall-like symptoms:
- Photograph and document the location of affected vines.
- Log the symptoms using the grower information form.
- For new vine plantings, contact your nursery supplier and VINA on 0429 772 221 or steve@armnursery.com.au.
- Contact the AWRI helpdesk on 08 8313 6600 or helpdesk@awri.com.au or advice on next steps..
Vineyard hygiene
There are currently no effective and practical methods available for completely eradicating crown gall once the bacteria are established in a vineyard, primarily due to their ability to persist in the soil for extended periods. Until more information becomes available, growers are strongly advised to adhere to best-practice farm-gate hygiene.
These measures include segregating vineyard activities between clean and diseased blocks, regularly disinfecting tools and equipment in contact with soil or vines, preventing the transfer of soil or plant debris between blocks, and ensuring contaminated water does not flow into clean areas or water storage facilities.
It is important to note that for farm-gate hygiene disinfestation procedures to be effective, they must address the target pest, disease or pathogen. The latest recommendation to disinfest footwear and small hand tools against crown gall is to use undiluted methylated spirits (95% ethanol) for 60 seconds with no water rinse thereafter**. This active concentration and time is also effective against phylloxera. Methylated spirits is flammable and as such, we caution flammability with use.
For both crown gall and phylloxera, follow the two-stage cleaning and disinfestation of footwear and small hand tools using Vinehealth’s protocol here. The efficacy of the ethanol will be prolonged by covering the footbath securely during daylight hours when not in use to prevent degradation, and replacing the ethanol at least daily or more frequently if it becomes soiled.
For general farm-gate hygiene activities (not written with crown gall as the focus), refer to Vinehealth’s Top 10 farm-gate hygiene activities fact sheet.
Assistance
For more information, refer to AWRI’s information on crown gall, including a fact sheet and ebulletin. This information will be updated as more information comes to light.
**While undiluted methylated spirits (95% ethanol) for 30 seconds is effective against phylloxera as a footbath, the recommended time of 60 seconds above for crown gall has been issued as a placeholder until efficacy studies can be completed.