Herbicides take the plunge against cabomba
From the February 2008 edition of Agriculture Today.
Trials being conducted by NSW Department of Primary Industries (DPI) at Grafton aim to find the most effective herbicide for use against submerged freshwater aquatic weeds, in particular cabomba.
Cabomba (Cabomba caroliniana) is a Weed of National Significance in Australia, infesting important waterways and waterbodies in NSW, Queensland, Victoria and the Northern Territory, and has the ability to spread by fragments on boats, trailers and fishing equipment.
It grows attached to the beds of dams, creeks and rivers with stems reaching lengths of up to 10 metres, causing water quality degradation, negative environmental impacts, public safety concerns and obstruction of irrigation systems.
Control options are currently limited to the mechanical removal of the weed using expensive aquatic harvesters, which really only "gives it a haircut", according to DPI weeds project officer at Grafton, Dr Elissa van Oosterhout.
Very few herbicides are registered for use on submerged aquatic weeds in Australia, and none of these will effectively control cabomba.
NSW DPI, with the support of the Australian Government’s Defeating the Weed Menace program, are trialling new herbicides at the Grafton Agricultural Research and Advisory Station, to support the registration of a safe and effective herbicide for use on cabomba in water.
It is hoped that a herbicide will be registered in the near future.
These herbicide trials support the development of best practice information for managing cabomba in Australia, which Dr van Oosterhout is researching and compiling.
"Along with a new herbicide registration, we will be able to give more detailed advice about improved methods of mechanical removal, other kinds of control methods including shading, and the best integration of all known approaches to cabomba management," said Dr van Oosterhout.
It is also hoped current research by CSIRO into potential biological control agents for cabomba will be successful in the near future.
Contact Elissa van Oosterhout, Grafton, (02) 6640 1661, elissa.van.oosterhout@dpi.nsw.gov.au
