Skip to main content
Tasmanian Government - www.tas.gov.au
Department of Primary Industries, Parks, Water and Environment
Structure of the Department
Careers at DPIPWE
Applying for a Job
Disability Access Plans
Personal Information Protection Policy
Public Interest Disclosures
Right to Information
RTI Disclosure Log
Investing in Irrigation
Farm Business Planning Tools
Enterprise Suitability Toolkit
Government and Community Programs
AgriGrowth Concessional Loans
Managing Seasonal Conditions
Women and Rural Communities
Identifying, Selling & Moving Livestock/NLIS
Codes of Practice & Guidelines
Spray Information and Incidents
Licences and Certificates
Chemical Registration and Permits
Land Management and Soils
Land Use Information
Facts and Figures
Weather and Climate
Traveller's Guide to Tasmanian Biosecurity - What You Can and Can't Bring into Tasmania
Latest Import Restrictions
Biosecurity Legislation Review
Current Biosecurity Threats
Animal Health Laboratories
Pest and Diseases
Plant Health Laboratories
Aquatic Pests and Diseases
Pacific Oyster Mortality Syndrome
Biosecurity Policy, Strategy & Publications
Biosecurity Policy, Strategy & Publications
Natural Heritage Strategy (2013-2030)
Flora of Tasmania
Lists of Threatened Species
Process for Listing Threatened Species
Tasmanian Wilderness World Heritage Area
Development Planning & Conservation Assessment
Conservation on Private Land
Private Land Conservation Program
Bush Information and Management
Natural Resource Management
Publications, Forms and Permits
Bag and Size Limits
Area Restriction Maps
Licences and Seasons
Publications and Products
Tas Fishing Guide App
Subscribe to Fishing News
Recreational Fishing Guide
Fishes of Tasmania Posters
Hot Fishing Spots
Rulers and Guides
Report Illegal Fishing
Calendar of Events
Sustainable Fisheries Management
Fishery Advisory Committees
Research and Stock Assessments
Marine Farm Planning Proposals
Biotoxin Fishery Events
Cat Management in Tasmania
Information for Cat Owners
Tasmanian Cat Management Plan
Controlling Stray and Feral Cats
Legislation and Management Plans
Recently Declared Weeds
Publications and Information Resources
Land Titles Office
Strata Title Information
Power of Attorney
Office of the Valuer General
Objecting to a Statutory Valuation
Property Valuation Adjustment Factors
Fees & Charges
Geospatial Infrastructure & Surveying
Register of Tasmanian Surveyors
Central Plan Register
Emergency Services GIS
Place Naming in Tasmania
Rules and Processes
Spatial Discovery - Educational Resources for Schools
Water Management Forms
A Guide to Water in Tasmania
Legislation, Policies and Strategies
Applying for a Licence
Transferring Licences and Allocation
Water Management Regions
Overview of Groundwater
Well Works Permits
Water Management Plans
Water Monitoring and Assessment
Urban Water and Sewerage Sector
Fauna of Tasmania
Reptiles and Frogs
Marine Conservation Program
Living with Wildlife
Management of Wildlife
Recreational Game Licences
Managing Wildlife Browsing & Grazing Losses
Caring for Wildlife
Forms and Permits
Aboriginal Heritage Tasmania
Analytical Services Tasmania
Animal Ethics Committee
Environment Protection Authority Tasmania (EPA)
Inland Fisheries Service Tasmania
Natural Values Atlas
Parks & Wildlife Service Tasmania
Port Arthur Historic Sites
Royal Tasmanian Botanical Gardens
Save the Tasmanian Devil
Threatened Species Link Tasmania
Water Information System of Tasmania (WIST)
Wellington Park Trust
Declared Weeds Index
Whiteweed - Control
Control of Whiteweed
Do's and don'ts of whiteweed control
Plan your control program, this will save time and money in the long-run;
Ensure cultivation, harvesting and road-grading machinery used in an infested area is washed down to remove whiteweed seed and root fragments;
Use sheep grazing to keep whiteweed down in pasture - but remember! sheep will not remove the weed from the soil;
Remember that when grazed pasture infested with whiteweed is cultivated for pasture or cropping, whiteweed numbers may increase dramatically from root fragments;
For cereals or forage-grass cultivation in whiteweed infested areas, use the herbicide
to control whiteweed; and
For cultivation of other crops in whiteweed infested areas, consider one or more initial cereal crop cycles with
treatment before planting non-cereal crops.
Don't introduce whiteweed to whiteweed free areas (e.g. by failing to wash down machinery and equipment between sites);
Don't start your control program without first planning your approach;
Don't expect sheep grazing to remove whiteweed from an infested area - whiteweed roots will remain in the soil and regenerate when sheep are removed;and
Don't cultivate herbaceous perennial crops (e.g. lucerne, essential oils) in areas heavily infested with whiteweed.
Spread of whiteweed
Whiteweed is a prolific seeder. However whiteweed seeds do not readily germinate under dense whiteweed infestations and seed is not usually important in the regeneration of established infestations. However, seed is an important method of spread of whiteweed into new areas.
Whiteweed has an extensive and persistent root system, reaching depths of over 1.5 meters. Regeneration of plants from root fragments following cultivation is rapid, and fragments are the principal method of spread of whiteweed within and between paddocks.
Avoid the introduction of whiteweed
Preventing the introduction of whiteweed to whiteweed free areas is the best means of control. Good hygiene practices are vital.
Machinery can carry both seeds and root fragments of whiteweed. Thorough cleaning of cultivation, harvesting and road-grading machinery which has been working in infested areas will greatly reduce the risk of spread into other areas
Hay and crop seeds can contain whiteweed seed if they have been sourced from infested paddocks.
Feed out hay in restricted areas on the farm and check for whiteweed seedlings.
Check cropping paddocks at an early stage of crop growth and remove any whiteweed before they become well established.
When infested pastures are cultivated for resowing to pasture or for cropping, whiteweed numbers may increase dramatically. This results from both the fragmentation of the root system during cultivation and the removal of grazing pressure.
Cultivation alone will not provide long-term control of whiteweed. Continuous cultivation will kill whiteweed roots in the topsoil, however new shoots can continue to emerge from roots below the depth of cultivation.
Whiteweed is readily grazed by sheep and may not be noticed in heavily grazed sheep pastures. However, grazing only removes the shoots of the plant and whiteweed will persist even under very heavy grazing.
Cattle and horses usually avoid grazing on whiteweed.
If a landholder resows to pasture or commences cropping in infested paddocks without being aware that whiteweed is present (due to heavy grazing by sheep), whiteweed may appear in large numbers from regeneration from root fragments.
Whiteweed may taint the meat of grazing stock, and sheep should not be used for control of the weed immediately before being sent for slaughter.
The choice of selective herbicides for whiteweed control in pasture and crops is relatively limited. See
Herbicides for Whiteweed Control
for more information.
No currently available herbicide can eliminate an established whiteweed infestation in one application. Follow up treatment is essential.
Selective chemical control of whiteweed is only available for cereal crops, forage grasses, pastures and some fruit crops. For other crops, whiteweed infestations should be reduced prior to crop sowing.
Integrated management of whiteweed
Control in permanent pasture
Heavy grazing by sheep is the best method of controlling whiteweed in permanent pasture. Stock that have grazed mature whiteweed plants can spread seed to clean areas, so grazing should be timed to avoid seed production.
Where sheep grazing is not possible, slashing of the flowering and seeding stems in spring may be used to reduce competition and to open up the infested area for grazing by cattle or horses. However, slashing will have little long-term effect on the whiteweed infestation, even if seed production is totally prevented.
Control in cropping systems
In pasture or fallow, treat whiteweed with herbicide at the bud stage in spring prior to cropping. Where crop sowing is to be undertaken immediately after herbicide application,
mixtures can be used. Where suitable crops (cereals or forage grasses) are to be sown in the following autumn, the herbicide
can be used. Consult an agronomist. Where herbicides are used adhere to product labels.
Where crops other than cereals or forage grasses are to be sown, no further herbicide treatment is available. Wherever possible, a cereal or grass crop should be sown as the initial crop in such areas. These crops can be treated with
Where the whiteweed infestation is very dense, a cereal cropping program may need to be undertaken for two seasons to gain control of the weed.
After one or more seasons of non-cereal cropping, the whiteweed may again increase to significant levels. In such situations, rotation back to a cereal crop and in-crop treatment with
may be necessary to reduce the infestation.
To the extent permitted by law, the Tasmanian Department of Primary Industries, Parks, Water and Environment (including its employees and consultants) excludes all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using information or material (in part or in whole) contained on this website.
About the Department
Animal Ethics Committee
Environment Protection Authority (EPA)
Parks & Wildlife Service
Sea Fishing & Aquaculture
fruit fly declarations