Issue 17
Monday, 09 October 2017
Charles Darwin University
PhD graduate Dr Enock Menge
PhD graduate Dr Enock Menge

Call for plan to beat emerging weed

By Patrick Nelson

A targeted strategy that extends beyond the Northern Territory’s borders is needed to combat the high-risk weed rubber bush, which a Charles Darwin University researcher says costs agriculture millions of dollars.

Dr Enock Menge, who will be awarded a PhD at CDU’s graduation ceremonies on Friday, said the wind-dispersed weed had infested between 1.8 million and 3.7 million hectares across Northern Australia, including valuable grasslands used for beef production.

“Rubber bush (Calotropis procera) is well adapted to arid and semi-arid conditions and has thrived in parts of the Northern Territory, Queensland, Western Australia and the northern parts of South Australia since its introduction to Australia as a garden ornamental plant about 100 years ago,” he said.

“It’s a threat to biodiversity, reduces agricultural productivity and is estimated to cost up to $750 per hectare in attempts to control it, besides the loss in productivity.”

Dr Menge, who is from the Barkly region, said his PhD research investigated whether rubber bush invasions were a symptom of rangeland management practices or a consequence of natural biological interactions with native species.

“We found that the more disturbed the soil, the higher the seed germination rate. In ground loosened by machinery, cattle or other animals, rubber bush was quick to colonise.”

Dr Menge said that to control the weed, policy frameworks concerning its management needed to be harmonised across the States and Territories where it grows.