Parkinsonia aculeata (parkinsonia) is a declared weed species which many mine sites in the Pilbara and Goldfields are required to control, as it is:
- A Weed of National Significance
- Listed as C3 (management) for much of Western Australia under the Biosecurity and Agriculture Management Act 2007.
Parkinsonia is regarded as one of the worst weeds in Australia because of its invasiveness, potential for spread, and economic and environmental impacts (National Heritage Trust 2015). The environmental impacts of parkinsonia include:
- Loss of native plant species
- Lower quality habitat for fauna
- Damming of water courses
- Lowering of water tables.
Through current projects, Astron works with the Pilbara Mesquite Management Committee (PMMC) to ensure best practice control measures and consistent data collection are undertaken. The PMMC is a not-for-profit group set up to tackle mesquite (Prosopis species) in the Pilbara. In 2009, the PMMC broadened their scope and took a leading role in the regional coordination and management of landscape-scale parkinsonia management. Astron has supported the group through in-kind development of management plans.
In undertaking control of parkinsonia at a number of mine sites in the Pilbara, Astron have found that spraying bark at the base of the trunk with a mixture of Garlon 600®TM and diesel is an effective control method. For larger individuals with a trunk diameter of more than 60 centimetres, a greater area of trunk needs to be treated (from the base to a height of 80 centimetres) to the point of run-off. Large individuals may also need follow up control the following year.
Control of parkinsonia is hard work, especially because of the Personal Protective Equipment required to be worn. For this reason, Astron recommends that in the Pilbara, control work should be conducted in the cooler months of the year (June to August). Conducting control at this time of the year will not reduce the efficacy of the herbicide as long as the plants are not experiencing other stresses.
Astron collects data electronically in the field when undertaking control of parkinsonia so that the effectiveness of control programs can be assessed. The field data can be used to compare density of individuals, number of individuals treated and effort expended in control between years.
References: National Heritage Trust 2015, Weed Management Guide Parkinsonia – Parkinsonia aculeata