Blueberry Rust Update

A recent detection of blueberry rust (Thekopsora minima) was made in the Melbourne metropolitan area.

Blueberry rust symptoms

The fungus Thekospora minima displays the following symptoms:

  • Initial yellow, chlorotic leaf spots on upper surface of young leaves
  • Lesions turn rust coloured as infection progresses
  • Yellow-orange pustules on underside of leaves, which can release spores and infect other leaves
  • Premature leaf drop and defoliation
  • The rust has two alternate hosts depending on climate and fungal spore stage. In colder climates it requires an alternative host to complete its lifecycle. Melbourne’s climate is considered suitable for overwintering on evergreen blueberry leaves so an alternate host is not required.
  • Southern highbush blueberries are more susceptible than other varieties

Blueberry rust symptoms

Blueberry rust hosts

The following are considered hosts of blueberry rust and have movement controls placed on them:

  • Vaccinium spp. (blueberries & cranberries)
  • Rhododendron spp. (azalea)
  • Lyonia spp.
  • Menziesia spp.
  • Pernettya spp.
  • Hugeria spp.
  • Gaylussacia spp. (huckleberries)
  • Tsuga spp. (hemlock)
  • Leucothoe spp.
  • Oxycoccus spp.
  • Pieris spp.

In Australia the infection has only been found on highbush blueberries, Vaccinium corymbosum.
Current status in Australia and movement conditions for blueberry rust host product:
NB:Plants may be required to meet other conditions not associated with blueberry rust.

VIC – DEPI have at this stage have only nine detections of the rust and these can be traced back to one property. In conjunction with DEPI these businesses have removed/destroyed or treated the infected plants and are complying with DEPI instructions.

A permit is still required if you intend on importing any blueberry rust host species into Victoria from the Blueberry Rust Restricted Area’s in QLD and NSW. See link for map: http://www2.dpi.qld.gov.au/extra/pdf/health/Blueberry-rust-restricted-area.pdf.

Contact DEPI on 136 186 for more information.

QLD – Blueberry rust is endemic (detection in 2011). No movement restrictions for hosts into this market.

NSW – Blueberry rust is endemic (detection in 2001). No movement restrictions for hosts into this market.

SA – Not present. No movement restrictions for hosts into this market.

NT – Not present. No movement restrictions for hosts into this market.

WA – Updated. Not accepting any blueberry rust host species unless plants have been grown in approved pre or post entry quarantine conditions. Quarantine WA prior to sending for further information: 08 9334 1800. UPDATE#2 - WA have stated that they would be willing to consider a proposal to import blueberry tissue cultures from Victoria. Contact NGIV or VIC DEPI for further info.

TAS – Updated. Refer to attached map of 200km buffer zone.
Within 200km of Victorian detection

  • Not accepting Vaccinium species unless plants have been grown in approved pre or post entry quarantine conditions
  • Blueberry rust host plants, other than Vaccinium species, can be visually inspected and if 100% free of the rust will be accepted. Contact VIC DEPI for inspections or further information: 136 186

Beyond 200km of Victorian detection

  • No restrictions apply
  • At present there is only one Interstate Certificaiton Assurance (ICA) Arrangement for blueberries and that is for fruit only. VIC DEPI are in discussions with DPIPWE (TAS) and WA for future movement options for Vaccinium spp. and alternate options for other blueberry rust hosts into the currently restricted markets.

Entry Pathways

It is still not known how it came to be in Victoria, but as it is a rust it can move vast distances. Vectors of the spores, which can survive approx 30 days, include:

  • Infected vegetative material (it is unclear a this stage if tissue culture is a vector)
  • Air movement of spores
  • Human assisted movement (vehicles/clothing/equipment/containers)
  • Water splash (rain/irrigation)

On-site hygiene

DEPI will be publishing a management guide shortly, but below are basic hygiene suggestions for your business if you currently grow any blueberry rust host product:

  • Ensure your staff have a high standard of awareness of the disease;
  • Advise staff to avoid any plant contact prior to arriving at work;
  • Have on-site disease identification information for all staff (see attached pictures);
  • Train staff on disease identification & good hygiene practices (see State biosecurity websites and Nursery Paper December 2004 Issue No: 11 at www.ngia.com.au);
  • Disinfect all equipment/vehicles that move off-site and return to operate within the production area;
  • Limit the access of people (visitors & staff) to your production areas;
  • Implement a hygiene protocol for essential visitors (contractors, etc) to production areas including awareness of previous work sites, inspection of clothing/tools, etc and if required provide disposable overalls while on-site;
  • Restrict all non-business vehicles from entry to production areas, disinfect if required on-site;
  • Minimise or allocate specific staff who come in contact with host material;
  • Source blueberry host plant material from known professional growers;
  • Inspect imported blueberry host material prior to incorporating into growing areas. A fungicide treatment may be appropriate, however be aware of withholding periods;
  • Monitor all host plant species regularly across growing areas for disease symptoms;
  • Ensure growing areas remain free of all waste vegetative material;
  • Treat with a disinfectant (e.g. Sporekill/quaternary ammonium) the growing area upon the completion of the crop growing cycle before placing a new crop down on the production bed. See Nursery hygiene papers or contact NGIV for specific rates.
  • Thoroughly inspect all host material prior to consigning it from your property for symptoms.

If you suspect you have found symptoms of blueberry rust, call the Exotic Plant Pest Hotline on 1800 084 881 or email biosecurity@dpi.nsw.gov.au. (and attach photos if possible).

For all other information please contact:
Industry Development Officer Michael Danelon on T. 02 9679 1472 or via email or
Industry Development Officer Des Boorman - Tweed-Brunswick & Northern Rivers on M. 0427 775 086 or via email.