Needle burr control

Page last updated: Wednesday, 31 August 2016 - 10:32am

Please note: This content may be out of date and is currently under review.

Control methods for needle burr (Amaranthus spinous) a declared pest in Western Australia.

Report the presence of this pest before undertaking control

Information about this pest can be found on the needle burr: 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.

Control options

Chemical control options can be found below. For other methods of control please refer to the aquatic weed control page, and the declared plant control handbook.

Chemical control options

Recommended herbicides

To prevent germination:

  • Metolachlor + atrazine; Trifluralin + simazine

Post emergent:

  • 2,4-D dimethylamine

Metolachlor + Atrazine (various trade names: see APVMA link)

Active ingredient

720g/L metolachlor (Group K) + 500g/L atrazine (Group C)

Amount of product/10L water

25mL metolachlor + 25mL atrazine

Rate of product/ha

2.4L/ha metolachlor + 2.5L/ha atrazine

Time of application

Apply to bare ground before any emergence has occurred


Moisture is required to wet the top 3-4cm of soil. If this is not available, incorporate the chemicals to 3-5cm depth

More information

Trifluralin 2.1-2.8L/ha + simazine 3-4L/ha was used under a minor use permit from Queensland and New South Wales for pre-emergence control

2,4-D (Group I) as the dimethylamine salt (various trade names: see APVMA link)

Active ingredient

  1. 500g/L dimethylamine salt of 2,4-D
  2. 625g/L

Amount of product/10L water


Rate of product/ha

  1. 2.2L
  2. 1.8L

Wetting agent dilution

BS-1000 @ 1mL/L

Time of application

Apply from seedling to just prior to flowering in non legume pastures. Maximum rate is:

  1. 5.5L
  2. 4.7L/ha

Contact information

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