Alligator weed control

Page last updated: Friday, 14 September 2018 - 1:33pm

Please note: This content may be out of date and is currently under review.

Control methods for alligator weed (Alternanthera philoxeroides) a declared pest in Western Australia.

Information about this pest can be found on the alligator 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 aquatic weed control page.

Recommended herbicides

  • Casoron
  • Metsulfuron methyl
  • Glyphosate

Herbicide: Casoron® (Group K)

Active ingredient

67.5g/kg dichlobenil

Rate of product

22g/m²

Remarks

Normally applied as a granule treatment, but can be mixed with water and applied as a foliar spray. In this case add a wetting agent such as BS-1000 @ 1mL/L. Do not apply to flowing water. Only apply to alligator weed mats.

Herbicide: Metsulfuron methyl (Group B) (various trade names: see APVMA link)

Active ingredient

600g/kg metsulfuron methyl

Rate of product/10L water

1g

Rate of product/ha

80g

Wetting agent

1:1000 – non-ionic surfactant such as BS-1000

Remarks

  • Follow up treatment required.
  • Healthy plants may need to be treated at fortnightly intervals.
  • Addition of glyphosate (360) at 100mL/10L may improve control.

Herbicide: Roundup, Biactive, Razor, Eraze, Weedmaster 360 Herbicide (Group M)

Active ingredient

360g/L glyphosate as the isopropylamine salt

Rate of product/10L water

100mL

Wetting agent

1:1000 – using a non-ionic surfactant such as BS-1000

Time of application

Summer to winter

Herbicide: Nufarm Credit Broadhectare Herbicide (Group M)

Active ingredient

540g/L glyphosate (present as the isopropylamine salt and mono-ammonium salts)

Rate of product/10L water

66–86mL

Wetting agent

Nufarm Bonus adjuvant/surfactant
At rates for a 1:1 ratio for example, 66mL of Bonus add 66mL Credit

Time of application

Summer to winter

Contact information

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