Distribution, invasiveness, biology and control of rubber bush (Calotropis procera) in northern Australia

The Distribution, invasiveness, biology and control of rubber bush (Calotropis procera) in northern Australia project aimed to understand the biology and impacts of rubber bush and contributed to effective management and control strategies.

Several prioritisation processes (Grice 2002, Martin et al. 2006) have listed rubber bush as an important economic and environmental weed in northern Australia’s rangelands. Rubber bush is a native to tropical Africa and Asia and was first introduced into Australia as an ornamental plant. Best estimates suggest it is now spread over 1.8 – 3.7 million ha in the Northern Territory, the Kimberley and north-west Queensland. Dense rubber bush infestations reduce livestock carrying capacity, increase chemical control costs and increase mustering costs. However there is conjecture whether rubber bush spread is a symptom or cause of poor land condition.

A national literature review by Grace (2006) and a Meat & Livestock Australia (MLA) sponsored rubber bush workshop (Tennant Creek, 2007) have identified distribution and spread, methods of control, biology, grazing effects and monitoring as key research gaps that need investigation to fully understand the invasiveness and potential impacts of rubber bush and how best to manage this weed. On-going concern expressed by producers and the Northern Beef Industry Committee was also a catalyst for development of this collaborative research project proposal.

This MLA funded project aimed to improve understanding of the distribution and rate of spread, reproductive biology, invasiveness and control of rubber bush and to enable more strategic, effective and cost-efficient management and control. This information supported management strategies to reduce future economic costs to industry from unchecked increases in rubber bush spread and density.

This project brought together pastoral land managers, researchers and natural resource management and primary production agencies from Queensland and the Northern Territory. Charles Darwin University and the Northern Territory Department of Land Resource Management were research partners in this project, performing specific components under a third party contractual agreement with Department of Agriculture and Fisheries. The final report should be available shortly.

When:  15 June 2010 to 30 May 2015

Where: Northern Australia

Contact: Shane Campbell

Collaborators: Department of Agriculture and FisheriesDepartment of Land Resource Management, Charles Darwin University