Herbicides for Californian Thistle Control

These herbicide recommendations are made subject to the product being registered for that purpose under relevant legislation. It is the user's responsibility to check that registration or an off-label permit covers the proposed use. Always read the herbicide label.

If in doubt, visit the Australian Pesticides and Veterinary Medicines Authority (APVMA) website at www.apvma.gov.au.

Only herbicides registered for use in pasture and non-cropping situations are listed in the following table. For recommendations in specific crops consult an agronomist.

Care must be taken in using herbicides as non-target plants contacted may be harmed.

Wetting agents

Carefully consult the product label for specific directions regarding the use of wetting agents or adjuvants.

Waterways and wetlands

Be careful! Many herbicides can cause damage to waterways and wetlands. Check the herbicide label directions carefully before use near waterways and wetlands. For more information see Guidelines for Safe and Effective Herbicide Use Near Waterways.

Herbicide Brands and Concentrations

Herbicides are referred to by the active chemical ingredient in the following table. The product trade names in this publication are supplied on the understanding that no preference between equivalent products is intended and that the inclusion of a product does not imply endorsement by DPIPWE over any other equivalent product from another manufacturer. Information on available brands containing the herbicide you require should be obtained from a reputable herbicide supplier or the APVMA website at www.apvma.gov.au.

There may be a number of products with the same active ingredient but with alternate formulations (concentration) registered for control of a weed eg: Glyphosate 360g/L, Glyphosate 450g/L may be registered for use on the same weed. Alternate formulations such as these will have a different application rate. Always check the label.

Herbicides for Californian thistle control

Boom spray application

Stage of Growth
Herbicide
(active
ingredient)
Example of commercial product (concentration of active ingredient)
Application rate of commercial product
Withholding
period
Comments
SeedlingsMCPA sodium(250 g/L)4.5 L/ha7 daysConsult your agronomist for tolerance levels for legumes should any be present.
From early bud to floweringMCPA amine(500 g/L)2.2L7 daysThe use of MCPA is preferred to 2,4-D (amine and ester) in situations where legumes are undersown in the crop.
Seedlings2,4-DB(500 g/L)3.5 L/ha7 daysUse in lucerne, or in areas where clover damage must be minimal, 2,4-DB gives reasonable short-term control.

For clover, apply from first to eighth trifoliate leaf stage.

This product may only be used from 15 April to 15 September unless permitted by the Registrar of Chemical Products, DPIPWE.
2, 4-D amine Amicide® 625
(625 g/L)
2.7 L7 daysRepeated applications may be necessary.

The use of MCPA is preferred to 2,4-D (amine and ester) in situations where legumes are undersown in the crop.

This product may only be used from 15 April to 15 September unless permitted by the Registrar of Chemical Products, DPIPWE.
From early bud to floweringClopyralidLontrel® 750 SG
(750 g/L)
800 g/ha28 daysAddition of adjuvant required in accordance with label.

Retreatment of growth in the year following treatment, will usually be necessary to achieve a high level control.

Clovers and medics will be eliminated for at least 12 months.
Actively growing/
flowering
GlyphosateRoundup PowerMAX™
(540 g/L)


(360 g/L)
7 L/ha




3 L/ha
1 day
(allow seven days for improved control)
Non-selective and will damage or kill trees and grasses that come into contact with spray drift.

Visible symptoms of treatment may take from 3-7 days to develop.

To ensure maximum shoot emergence the area should not be cultivated prior to spraying.

Re-treatment and/or pasture improvement may be necessary to restrict seedling re-establishment.
Roundup® Biactive™
(360 g/L)
3 L/ha1 day
(allow seven days for improved control)
Suitable for use near waterways.

Non-selective and will damage or kill trees and grasses that come into contact with spray drift.

Visible symptoms of treatment may take from 3-7 days to develop.

To ensure maximum shoot emergence the area should not be cultivated prior to spraying.

Re-treatment and/or pasture improvement may be necessary to restrict seedling re-establishment.

Spot spray application

Stage of Growth
Herbicide
(active
ingredient)
Example of commercial product (concentration of active ingredient)
Application rate of commercial product
Withholding
period
Comments
From early bud to floweringMCPA(500 g/L)20ml - 40ml/ 10 L water7 daysThe higher rate will improve control but will increase clover damage in pasture situations.
Seedlings2,4-DB(400 g/L)5 ml/L7 days This product may only be used from 15 April to 15 September unless permitted by the Registrar of Chemical Products, DPIPWE.
From early bud to floweringClopyralidLontrel® 750 SG
(750 g/L)
10 g/ 10L water28 daysAddition of adjuvant required in accordance with label.

Retreatment of growth in the year following treatment, will usually be necessary to achieve a high level control.
Clovers and medics will be eliminated for at least 12 months.
FloweringGlyphosateRoundup PowerMAX™
(540 g/L)

(360 g/L)
7 L/ha



10 ml/L
1 day
(allow seven days for improved control)
Non-selective and will damage or kill trees and grasses that come into contact with spray drift.

Visible symptoms of treatment may take from 3-7 days to develop.

To ensure maximum shoot emergence the area should not be cultivated prior to spraying.

Re-treatment and/or pasture improvement may be necessary to restrict seedling re-establishment.
Roundup® Biactive™
(360 g/L)
3 L/ha1 day
(allow seven days for improved control)
Suitable for use near waterways.

Non-selective and will damage or kill trees and grasses that come into contact with spray drift.

Visible symptoms of treatment may take from 3-7 days to develop.

To ensure maximum shoot emergence the area should not be cultivated prior to spraying.

Re-treatment and/or pasture improvement may be necessary to restrict seedling re-establishment.

Important Disclaimer
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.