Biological control is the use of natural enemies such as diseases, mites and insects to suppress and weaken the target weed.
Currently the only biological control agent tested and released into Australia is the leaf rust fungus (Phragmidium violaceum), which attacks only European blackberry. The rust is highly efficient at spreading by natural means and will colonise blackberry when environmental conditions are suitable. Therefore, land managers do not need to redistribute the rust.
Blackberry leaf rust fungus primarily attacks the leaves of blackberry and causes defoliation. It can also be found on flower buds and unripe fruit. The tips of the heavily attacked stems die back, preventing the production of daughter plants at the end of the stems. The rust also obtains nutrients and water from the blackberry plant cells, reducing the plant’s overall ability to grow and reproduce.
The strategy being implemented to facilitate the spread of the new strains of the fungus recently introduced to Australia is to release them at a range of sites across Australia to help the natural spread of the agent. It is well documented that the rust can spread over long distances. The new strains may become established, build up and hybridise with the existing rust populations, and better rust genotypes could emerge. The better genotypes that emerge will enhance the biological control of blackberry at some sites and eventually will spread to other infestations.
New rust research
There is currently new research being undertake to assess purple blotch disease (Septocyta ruborum). This is a priority agent for further development as it is systemic, capable of killing canes and whole plants, has a broad climatic range and many invasive taxa are susceptible. For further research updates, please refer to our Annual Report.
Purple Blotch Update
Purple Blotch Update: May 2016
Biological Control Presentations:
Bio-control of Blackberry 2017
Robin Adair – PowerPoint Presentation
Pathogens for Blackberry Biocontrol
Dr Louise Morin – Forum Presentation:
Managing Crown Land Boundaries, Cudgewa, 18 August 2016
Blackberry Biocontrol & the Atlas of Living Australia
Learning & sharing via your smartphone – Greg Lefoe
Invertebrate options – Raelene Kwong / Role for citizen science – Greg Lefoe