Herbicides for St John's Wort 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. Care must be taken in using herbicides as non-target plants contacted may be harmed. For recommendations in specific crops consult an agronomist.

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 some with alternate formulations (concentration) registered for control of a weed eg: Glyphosate 360 g/L, Glyphosate 450 g/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.

Foliar spray application

Stage of Growth
Herbicide
(active
ingredient)
Example of commercial product (concentration of active ingredient)
Application rate of commercial product
Withholding
period
Comments
While actively growing - flowering to post floweringGlyphosate Round-Up
(360 g/L)
50 ml/10L

nilGenerally November - May.

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

May result in bare ground encouraging further seedling establishment: follow-up will be required.
Round-Up Biactive®, Weedmaster Duo® (360 g/L)50 ml/10LSuitable for use near waterways.

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

May result in bare ground encouraging further seedling establishment: follow-up will be required.
SickleTM
(540 g/L)
33 ml/10L
Pre - early floweringTriclopyr Garlon 600® (600g/L)
17 ml/10L
nil
Will not affect grasses, will severely damage clovers and other broadleaved plants, including surrounding trees, if contacted by the spray.
Brush-Off®, Associate®, Ally®
(600 g/Kg)
1 - 1.5 g/10L
nil
Will not affect grasses, will severely damage clovers and other broadleaved plants, including surrounding trees, if contacted by the spray.

Soil-residual, hindering the re-establishment of clovers and other broadleaved plants for 6-12 months.

Metsulfuron-methyl + glyphosate Trounce, Cut-Out (various concentrations)Refer to label nilWill not affect grasses, will severely damage clovers and other broadleaved plants, including surrounding trees, if contacted by the spray.

Soil-residual, hindering the re-establishment of clovers and other broadleaved plants for 6-12 months.
Flowering to early seed setTriclopyr + picloram** + aminopyralidGrazon Extra (300g/L + 100 g/L + 8 g/L)50 ml/10LnilWill not affect grasses, will severely damage clovers and other broadleaved plants, including surrounding trees, if contacted by the spray.

Soil-residual, hindering the re-establishment of clovers and other broadleaved plants for 6-12 months.
FluroxypyrStarane AdvancedTM (333 g/L)30 ml/10L7 daysUsually late spring - early January.
**Note: picloram remains active in the soil for extended periods and may leach into groundwater.

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
Pre flowering, up to 40cm high2,4-D EsterLV Ester® 600 (600 g/L)3.7 - 5.3 L/ha7 daysFor non-legume pastures.

This product may only be used from 15 April to 15 September unless permitted by the Registrar of Chemical Products, DPIPWE.
Bud to full bloomFluroxypyrStarane AdvancedTM (333 g/L)1.8 L /ha7 daysUsually late November - early January.

Some regrowth may occur, treat the following season for best results. Use at least 200L water/ha.
While actively growing - flowering to post floweringGlyphosate Round-Up
(360 g/L)
3 L /ha





nilGenerally November - May.

Non-selective and will damage or kill trees and grasses that come into contact with spray.
Round-Up Biactive®, Weedmaster Duo® (360 g/L)Suitable for use near waterways.

Non-selective and will damage or kill trees and grasses that come into contact with spray.
SickleTM (540g/L)2L /ha

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