Blackberry - a weed of national significance



Introduction

There are about thirty weeds of national significance (WoNS), declared by the Commonwealth Government as important because of their potential to spread and to cause severe economic and/or environmental damage. Blackberry, bridal creeper, boneseed, gorse and lantana are WoNS which occur in the Torbay Catchment and the group has particularly targeted blackberry, as it was identified in a 2010 survey of landholders as being of most concern.

There are some Australian native species of blackberry, although none occur in Western Australia. The weedy species were first introduced into Australia in the 1830s, and came from Europe, North America and Asia.

Introduced blackberry can quickly dominate the land it invades as it grows vigorously, is prickly and able to propagate vegetatively from cane tips. Blackberry effectively spreads seed through fruit eating birds and mammals (including foxes). Once established, it competes strongly with both agricultural and natural ecosystems. Natural ecosystems are affected by a decrease in biodiversity, the impact of feral animals harboured by blackberry thickets, and a decrease in the ecotourism dollars as a result of reducing the desirability of the natural environment.

There is a lot of information on weeds, WoNs and blackberry available on the web. weeds.org.au is very comprehensive; their site map is reproduced below, and you can click on the red "Weeds of National Significance" branch to go to their WoNS page or the blue "blackberry" to go to their blackberry page. From there you can find information on identification, distribution and control methods.

Other useful links are:

Blackberry in Western Australia

There are three species of blackberry in Western Australia. They are:

  • common blackberry (Rubus anglocandicans)
  • small leaf blackberry (Rubus ulmifolius)
  • early blackberry (Rubus laudatus)
The taxonomy of blackberry species is particularly complex and in the past these species have been referred to by a variety of common and Latin names. More information on blackberry identification in Western Australia can be obtained from the Weeds Australia WA field guide.

Blackberry in the Torbay Catchment

Rubus laudatus has only been found around the Metropolitan area and adjacent regions but the other two species occur in or near the Torbay Catchment. Rubus anglocandicans and Rubus ulmifolius both come from Europe and so are suseptible to some degree to the blackberry leaf-rust fungus (Phragmidium violaceum), which can be used as a biological control agent. However this pathogen cannot be relied on to prevent the spread of blackberry so an integrated approach is required.

Landholders wanting advice on ways to control blackberry (including non-chemical use) and identifying difference species can view the Weeds.org Blackberry Control Brochure and Manual. In addition, the state Department of Agriculture and Food provides detailed guidelines on chemical control of blackberry in a "declared plant" brochure.

Interested landholders can log into the Weed Watcher portal on the Department of Agriculture and Food website and very easily record blackberry either on their own properties or elsewhere in the catchment. Switching to the satellite view on Google maps might make it easier to accurately pin point the site. Information collected in this way by members of the public and community groups with an interest in weed management is intended to augment other data collected by Government agencies and specialist research organisations to support the management of significant weeds in Australia.

The Torbay Catchment Group has received funding through the Commonwealth Government and a Community Action Grant to implement a blackberry control strategy in the Torbay Catchment. In 2102 and 2013 blackberry infestations in the catchment were sprayed utilising Gazon Extra or manually removed. As a result of a weed workshop held in 2013, a Torbay Weeds Action Group was formed, and this group plans to continue the control program, especially in the no-spray zone around the Torbay Hall and in the priority drinking water areas where spraying is not allowed.