Weeds

Weeds pose a serious risk for primary producers as they can impact on market access and agricultural production.

In 2006/07, each Western Australian agricultural business spent an average of $29 376 ($341 million total) on weed control (Australian Bureau of Statistics).

Weed control is a shared responsibility between landholders, grower groups, biosecurity groups and the Department of Primary Industries and Regional Development.

To protect WA’s agriculture, the department:

works with landholders, grower groups, community groups and biosecurity groups
regulates weeds under the Biosecurity and Agriculture Management Act 2007
provides a weed identification service
provides a predictive simulation tool called weed seed wizard
provides information on weed control, crop weeds, regulated/declared plants and herbicides
contributes to social science through weedwatcher.

For advice on weeds search our website, the Western Australian Organism List or contact our Pest and Disease Information Service (PaDIS).

For diagnostic services, please contact our Diagnostic Laboratory Services.

Articles

Factors affecting herbicide performance

19 January 2011

Herbicide performance can vary greatly depending on a number of factors. These can include compatibility of herbicides, water quality, sprayer decontamination and controlling stressed weeds.
Residual herbicides - carryover and behaviour in dry conditions

8 June 2018

The term 'residual' applies to a number of herbicides that have a long lasting activity in the soil. These herbicides are often applied directly to the soil prior to planting crops, pre-emergent.
Soil inversion to ameliorate soil water repellence

19 December 2010

One-off soil inversion results in the complete burial of the water repellent topsoil in a layer typically at a depth of 15 to 35 cm, and brings to the surface a layer of wettable subsoil.
Windmill grass

23 May 2012

Windmill grass (Chloris truncata) is a native species and is the tenth most common summer weed species in the Western Australian wheatbelt.
Annual ryegrass

6 October 2011

Annual ryegrass (Lolium rigidum) is one of the most serious and costly weeds of annual winter cropping systems in southern Australia.
Management of brome grass

20 March 2014

Brome grasses (Bromus spp.) are highly competitive weeds, most problematic in wheat crops.
Weed Seed Wizard details

15 August 2012

The Weed Seed Wizard is a computer simulation tool that uses paddock management information to predict weed emergence and crop losses.
Crop weeds: Hygiene - prevent weed seed introduction

29 May 2012

‘Risk-aware’ growers can implement strategies to reduce and avoid unnecessary introduction and spread of weeds.
Assessing weed population density

27 January 2011

The most accurate way to estimate the weed population of a paddock is to count the number of plants in an area of known size at a number of locations.
Capeweed reduces crop yield

4 February 2011

In Western Australia, competition from 7-90 capeweed plants per square metre in a wheat crop can reduce crop yield by 28-44% and net return by 25-76%.