Herbicides for Slender 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 manufacturer's herbicide label.

If in doubt, visit the Australian Pesticides and Veterinary Medicines Authority (APVMA) website: 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 the guideline, 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: 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.

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
Seedlings	MCPA sodium salt	(250 g/L)	4.5 L/ha	7 days	Apply to mature grasses. Consult your agronomist for tolerance levels for legumes should any be present.
	MCPA amine	(500 g/L)	3 L/ha	7 days	The use of MCPA is preferred to 2,4-D (amine and ester) in situations where legumes are undersown in the crop.
	MCPA amine	Agritone® 750 (750 g/L)	2 L/ha	7 days
	2, 4-D amine	Amicide® 625 (625 g/L)	1.4 L/ha	7 days	Suppression only. 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.
Rosette	2, 4-D ester	Estercide® Xtra 680 (680 g/L)	800ml - 3.3 L/ha	7 days	Use when thistles have started to shoot and become more resistant to other herbicides. User higher rates on larger plants. 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.
Seedling -young rosette	MCPA + Dicamba	Kamba® M (340 g/L MCPA+ 80 g/L Dicamba)	2.8 - 4.0 L/ha	7 days	Use higher rate on larger weeds.
Rosette stage prior to stem elongation	Clopyralid	Lontrel® 750 SG (750 g/L)	20 or 28 g/ha + 1 - 1.5L/ha MCPA amine (500 g/L)	7 days	Spray during active growth. Use higher rates on multicrowned plants or large rosettes. Clovers and medics will be eliminated for at least 12 months.

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
Seedlings	MCPA sodium salt	(250 g/L)	350 ml per 15L water	7 days	Thorough coverage is essential. 15L of solution is sufficient to cover 150m².
	MCPA amine	(500 g/L)	30 mL/10L water	7 days	The use of MCPA is preferred to 2,4-D (amine and ester) in situations where legumes are undersown in the crop.
	MCPA amine	Agritone® 750 750 g/L	20 mL/10 L water
	2, 4-D amine	Amicide® 625 625 g/L	14 mL/10 L water	7 days	Suppression only. 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.
Rosette	2, 4-D ester	Estercide® Xtra 680 (680 g/L)	8 mL - 33 mL/10 L water	7 days	Use when thistles have started to shoot and become more resistant to other herbicides. 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.
Seedling - young rosette	MCPA + Dicamba	Kamba® M (340 g/L MCPA+ 80 g/L Dicamba)	60 mL - 80 mL/15 L water	7 days	Use higher rate on larger weeds.
Early flowering plants	Clopyralid	Lontrel® 750 SG (750 g/L)	10 g/10 L water	7 days	Can be used on early flowering plants to reduce seed formation. Top 10 - 20 cm of sprayed plants collapse within 12-24 hours of treatment, allowing missed plants to be located and treated.

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.