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Thumper Herbicide Bayer CropScience



The Kochia Killer

Thumper® provides reliable and outstanding control of over 26 broadleaf weeds including kochia (including Group 2- and 9-resistant biotypes), Russian thistle and wild buckwheat all while providing excellent crop safety in your wheat and barley. Thumper contains both Group 4 (2,4-D) and Group 6 (bromoxynil) active ingredients, making it an effective resistance management tool. Available in 320-acre Bulk shuttles and convenient 1,000-acre Bulk totes.

Product Summary


Product Type

  • Herbicide




  • Broadleaf
Weeds Surpressed

Weeds Controlled (Top 6)

  • Kochia
  • Volunteer Canola
  • Lamb's-quarters
Groups and Active Ingredients

Groups and Active Ingredients

  • Bromoxynil Group 6
  • 2,4-D Group 4
Formulation Type

Formulation Type

  • Liquid-emulsifiable Concentrate


  • 8 L Jug (20 ac)
  • 128 L Bulk Shuttle (320 ac)
  • 400 L Bulk Tote (1,000 ac)

Key Product Points

  • Thumper provides effective control of over 26 broadleaf weeds.
  • Contains Group 4 and 6 active ingredients, making it a valuable tool for managing wild buckwheat and Group-9 resistant kochia.

Active Ingredients

Bromoxynil – Group 6
2,4-D – Group 4


Wheat, durum
Wheat, spring
Wheat, winter

Weeds Controlled

American Nightshade
Ball mustard
Common buckwheat
Common groundselle
Common ragweed
Cow cockle
Green smartweed
Night-flowering catchfly
Pale smartweed
Redroot pigweed
Russian thistle
Shepherd's purse
Tartary buckwheat
Triazline-resistant pigweed
Volunteer canola
Volunteer sunflower
Wild buckwheat
Wild mustard

Province of Registration

British Columbia

Approved Tank Mixes

Liquid Achieve®
Puma® Advance
Sevin® XLR

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Application Guidelines


  • Registered for use in wheat and barley
  • Control of 26 broadleaf weeds including Group 2- and 9-resistant kochia
  • Excellent crop safety
  • No re-cropping restrictions
  • Registered for aerial application
  • Numerous tank-mix options available
  • Effective resistance management – contains Group 4 (2,4-D) and Group 6 (bromoxynil) active ingredients
  • When Thumper® is tank mixed with Varro®, the combination provides three modes of action (Groups 2, 4 and 6) against broadleaf weeds
  • Combining differing modes of action has been identified as a very effective way to manage and reduce the potential for the development of resistant populations.
  • Available in Bulk


Application Tips

0.4 L/ac. (20 ac./jug)


Spring wheat (including durum) and barley may be treated from the 4 leaf stage until the early flag leaf stage. Application before the 4 leaf stage may result in crop injury.


  • 8 L jug = 20 acres (one 2 x 8 L case treats 40 acres)
  • 128 L Bulk shuttle = 320 acres
  • 400 L Bulk tote = 1,000 acres


Water Volume
  • Ground – minimum of 5 US gal./ac. (19 L/ac.)
  • Aerial – minimum of 3 US gal./ac. (11 L/ac.)
  • Bromoxynil is a contact herbicide and coverage is integral for weed control. Where possible, maintain water volumes at minimum levels to ensure control.


One hour after application


Residue and Grazing
Do not graze or cut for forage hay within 30 days after spraying


Re-cropping Intervals
No re-cropping restrictions


Thumper vs. Competitors

Kochia Control


Average of Thumper vs. Average of Attain


Boost Your Broadleaf Control

Tank mix Varro® with Thumper and boost your broadleaf control. This combination contains three modes of action with Groups 2, 4 and 6, making an already strong broadleaf concept even more robust.

Thumper and Varro
Source: 8 internal Bayer trials, 2006.

Resistance Management

Thumper herbicide – Group 6 has no known resistance in Western Canada

Thumper has two different modes of action (Group 6 and Group 4) making it an ideal resistance management tool for growers with broadleaf resistance concerns like Group 9- and Group 2-resistant kochia. The two active ingredients provide a combination of both systemic and contact activity with exceptional crop safety and no re-cropping restrictions.

  • Powerful control of 26 broadleaf weeds, including Group 2- and Group 9-resistant kochia
  • Group 4 and Group 6 active ingredients make Thumper an effective resistance management tool
  • Dual mode of action provides both systemic and contact activity

What is Resistance?

Resistance is a naturally occuring, inherited ability of some weed biotypes to survive a herbicide treatment that should, under normal use conditions, effectively control a weed population. Some herbicide resistant weeds have naturally developed one or more mechanisms that allow them to survive a herbicide treatment.

For a weed to be considered resistant it must:

  • Normally be controlled by the herbicide
  • Survive a usually lethal dose of the herbicide
  • Be heritable, meaning it is passed from generation to generation

Herbicide-resistant individuals are naturally present within a weed population at very low frequencies.

Did you know that there is no known resistance to Group 6 herbicides in Western Canada?

What's the impact to farming in Western Canada?

Why is it important to you?

The management issues and yield concerns with herbicide resistance are very real, especially now with an increasing number of herbicide resistant weeds spreading across Western Canada.

Loss of viable herbicide options

  • Have to rely on currently available herbicides for the foreseeable future
  • No herbicides with new modes of action are in advanced trials

Would require changes in weed and crop management practices

  • Zero or reduced tillage rely heavily on herbicides for weed control

Reduced return on investment

  • Increase the cost of weed management
  • Loss of yield potential

The number of weeds with herbicide resistance continues to rise

  • Including weeds resistant to multiple modes of action

How does resistance develop?

The image below demonstrates the interaction between a weed species and a particular mode of action and the development of herbicide resistance at different speeds. It’s clear to see that over time the use of a herbicide quickly changes from being very effective to becoming extremely ineffectual. In fact, by the fifth year of application the herbicide is failing to eliminate herbicide-resistant weeds. It is particularly alarming that there is a dramatic increase in failure rate from the fourth to fifth season.

Development of Herbicide Resistance

% Resistant Weeds in Population Weed Control
0 Application .0001% Excellent
1st Application .00143% Excellent
2nd Application .0205% Excellent
3rd Application .294% Excellent
4th Application 4.22% Excellent
5th Application 60.5% Failure
Source: Weed Science Society of America, 2011

What can you do to delay the onset of herbicide resistance?

  • Don’t rely solely on herbicides for weed control
  • Develop field-specific long-term weed management plans
  • Rotate herbicide groups year over year

General guidelines for herbicide rotations:

  • Avoid repeated use of the same herbicide or herbicides having the same mode of action in the same field year to year
  • Limit the number of applications of a single herbicide or herbicides having the same site of action in a single growing season
  • Use mixtures or sequential treatments of herbicides having different modes of action which are active on the same target weeds whenever possible
  • Use non-selective herbicides pre-seed or pre-emergence to control early flushing weeds (prior to crop emergence) and/or weed escapes

Resistant weed management strategies

  2. Rotate crops as often as possible to utilize the unique modes of action available within the crop.

  4. Time and place fertilizer to benefit your crop, not weeds.

  6. Systematically target problem weeds and respond quickly to changing weed populations.

  8. Scout often and take note of individual weed response to all applications (pre-emergent, post-emergent and pre-harvest).

  10. Make sure you remove all weeds before they set seed – even if you have to pull by hand. Remember the old English proverb: One year seeding, seven years weeding.

  12. Leaving a 1m wide weed-free zone around your cropping fields (so new weeds can’t propagate and expand throughout your fields).

  14. Decrease your row spacing and increase seeding rates to optimize plant populations, maximize crop competitiveness and minimize time to crop canopy closure.

    • Match selection of herbicide(s) with your most difficult weeds.
    • Use full-labelled rates.
    • Include the best tank mixes and adjuvant(s).
    • Use correct spray volume (follow label directions).
    • Use correct nozzle spacing and droplet size.
    • Don’t spray at excess travel speeds, follow label directions.
    • Apply during the best weather conditions (warm, humid, and sunny conditions with minimal wind).
    • Maximize rain-fastness intervals.
    • Time of day (herbicides are most effective when sprayed between 8:00am and 9:00pm).

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