Parthenium weed control

Page last updated: Wednesday, 16 October 2019 - 10:25am

Control methods for parthenium weed (Parthenium hysterophorus) a declared pest in Western Australia.

REPORT THE PRESENCE OF THIS PEST BEFORE UNDERTAKING CONTROL

Information about this pest can be found on the parthenium weed: declared pest page.

Chemical requirements

When using any agricultural chemicals please ensure that you always follow instructions on the label and any permit. Users of agricultural chemical products must always strictly comply with the directions on the label and the conditions of any permit. To view permits or product labels go to the Australian Pesticides and Veterinary Medicines Authority website.

Chemical control options

Chemical control options can be found below. For other methods of control please refer to the declared plant control handbook.

Recommended herbicides

Young, actively growing

  • 2,4-D (agricultural)
  • Picloram + 2,4-D amine (agricultural)
  • Glyphosate + metsulfuron (agricultural)
  • Paraquat + diquat (roadsides and non agricultural)

Seedlings and mature plants

  • Dicamba (agricultural)

Herbicide: Paraquat + diquat (Group L) various trade names: see APVMA link

Active ingredient

135g/L paraquat and 115g/L diquat

Amount of product/10L water

  1. 25–30mL

Rate of product/ha

  1. 2.5–3L
  2. 1.6–2.4L

Wetting agent dilution

1:400

Time of application

Young, and actively growing

Remarks

  1. For public service areas, vegetable, orchard and vineyards. Use higher rates for dense infestations.
  2. For annual weed control in pastures

Herbicide: 2,4-D amine (Group I) (various trade names: see APVMA link)

Active ingredient

500g/L 2,4-D amine

Rates of dilution for spot spraying

1:250

Amount of product/10L water

40mL

Wetting agent dilution

1:400

Time of application

Young, and actively growing

Remarks

  • Industrial, non-agricultural use and for pastures
  • Other formulations of 2,4-D available are 475, 625 and 720g/L and 800g/kg. If using these adjust rates accordingly.

Herbicide: Picloram + 2,4-D amine (Group I) (various trade names: see APVMA link)

Active ingredient

75g/L picloram + 300g/L 2,4-D amine

Rates of dilution for spot spraying

1:1000

Amount of product/10L water

30mL

Rate of product/ha

3L/ha

Wetting agent dilution

1:400

Time of application

Young, and actively growing

Remarks

Agricultural use will remove clovers and some broad leaf pasture such as capeweed for at least 12 months

More information and other control methods

For non-agricultural use at 30mL per 10L of water, i.e. 3L/ha

Herbicide: Glyphosate + metsulfuron (various trade names: see APVMA link)

Active ingredient

360g/L glyphosate (Group M) + 600g/kg metsulfuron methyl (Group B)

Amount of product/10L water

10mL glyphosate + 0.1g metsulfuron

Rate of product/ha

0.8–1.2L glyphosate + 5–7g metsulfuron

Wetting agent dilution

1:400

Time of application

Young, and actively growing

Remarks

Agricultural applications

More information and other control methods

Metsulfuron can be used at same rates without the addition of glyphosate

Other concentrations of glyphosate can be substituted for the 360g/L by adjusting the rates:

  • 450g/L glyphosate = 0.8L/ha
  • 490/500g/L glyphosate = 0.7L/ha
  • ​​680g/kg glyphosate = 500g/ha

Herbicide: Dicamba (Group I) (various trade names: see APVMA link)

Active ingredient

500g/L concentrations

Amount of product/10L water

10mL

Rate of product/ha

0.56L–1.1L

Wetting agent dilution

1:400

Remarks

Low rates for seedlings, higher rates for mature plants

Contact information

Pest and Disease Information Service (PaDIS)
+61 (0)8 9368 3080