Blackberry is a weed of national significance due to its damaging impact on the environment. The control of blackberry is required by ACT legislation. Blackberries are controlled with herbicide at priority locations across the ACT. Warning signs are placed at these locations. If you see a sign warning not to eat the Blackberry fruit or a weed spraying in progress sign, then you should avoid eating Blackberry fruit in that area noting that fruiting times vary at each location and can occur anytime from December to May.
Fungus used to fight blackberry in the ACT
The ACT Parks and Conservation Service has started using a new tool in the fight against blackberry, the microscopic phragmidium violaceum fungus, also known as blackberry rust. The fungus, which exclusively feeds on blackberry plants, was released at specific sites in the ACT to help combat the pest species. Blackberry rust affects the host plant by causing it to lose its leaves. This slows and controls the rate the infected plant can colonise the surrounding landscape with runners and viable seeds.
The fungus being used is a new strain developed by the CSIRO from European strains. It has already been successfully released in New South Wales by the NSW Government. Infected blackberry leaves were collected from a nursery site near Tumbarumba in NSW and transported back to the ACT. Releasing the fungus is as simple as stapling the infected leaves onto the leaves of the host blackberry plant. The sites chosen to release this first wave of blackberry rust were selected because they had viable and healthy hosts to infect and also to ensure the rust could effectively spread between blackberry populations.
Rangers will continue to monitor the release sites to map the effectiveness of the rust on the host blackberry.