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Less wild oats. More what you love.



Varro – for wheat fields worth looking at.

Wild oats can make your fields stand out for all the wrong reason. Varro® herbicide puts you in control of wild oats and other tough grass weeds, while also providing a broadleaf booster. A Group 2 graminicide, you can use Varro at one rate in a variety of tank mixes, helping you manage resistance on your farm.

Product Summary


Product Type

  • Herbicide




  • Broadleaf & Grass Weeds
Weeds Surpressed

Weeds Controlled (Top 6)

  • Barnyard Grass
  • Wild Oats
  • Green Foxtail
Groups and Active Ingredients

Groups and Active Ingredients

  • Thiencarbazone-Methyl Group 2
Formulation Type

Formulation Type

  • Liquid OD Formulation


  • 8L Jug (40 ac)

Key Product Points

  • With outstanding control of wild oats and other problematic grass weeds, it provides you with a clean wheat field you can be proud of.
  • A powerful early-weed removal specialist, it offers effective resistance management and allows you the flexibility to rotate back to pulse crops.

Varro Advantage

Features and Benefits

  • Strong performance on grass weeds like wild oats, barnyard grass, Persian darnel, green and yellow foxtail, canary seed and Japanese brome
  • Group 2 technology allows for control of problematic Group 1-resistant wild oats and foxtail
  • Allows crop rotation flexibility to sensitive crops like dry beans and lentils
  • Enhances the overall control of its broadleaf tank-mix partners
  • Exceptional crop safety
  • Registered for ground and aerial application

Varro vs. The Competition

Varro for Wild Oat Control

Varro for Wild Oat Control Graph

Source: 5 Bayer Internal Trials.
Your results may vary according to agronomic, environmental and pest pressure variables.

Varro for Green Foxtail Control

Varro for Green Foxtail Control Graph

Source: 3 Bayer Internal Trials.
Your results may vary according to agronomic, environmental and pest pressure variables.

Varro for Yellow Foxtail Control

Varro for Yellow Foxtail Control Graph

Source: 2 Bayer Internal Trials.
Your results may vary according to agronomic, environmental and pest pressure variables.

Active Ingredients

Group 2
Group 2



Wheat, Durum
Wheat, Spring
Wheat, Winter

Weeds Controlled

Varro Varro + AMS1
Grass Weeds
Barnyard grass E E
Canary seed G+ VG
Green foxtail G G+
Japanese brome (fall germinated)1 S S+
Japanese brome (spring germinated)1 G G
Persian darnel S S
Wild oats VG VG+
Yellow foxtail S S+
Broadleaf Weeds
Cleavers G G+
Hemp-nettle E E
Lady's thumb/Smartweed G G
Lamb's-quarters S S+
Redroot pigweed G G
Round-leaved mallow S S
Russian thistle S S
Shepherd's-purse G G
Stinkweed G G
Volunteer canola G G
Wild buckwheat S S
Wild mustard VG VG

Weed Control

< 84%

1 Velocity m3/Varro + AMS for use on spring and winter wheat only. In durum wheat, add a non-ionic surfactant.

Approved Tank Mixes

jug icon

Get the Max from your Tank Mix

Our tank mix tool can help you find the best tank mix partner for the Bayer herbicide you’re using.
Tank Mix Tool

Early Weed Removal To learn more about how you can achieve a +10% yield increase with Varro herbicide, click here.

Application Tips

0.20 L/ac.


Crops/Application Timing
  • Apply Varro from the 1 to 6 leaf stage on the main stem up to emergence of the third tiller, but before appearance of the first node (jointing)
  • Avoid crop injury: do not apply an ALS herbicide such as Varro following the appearance of the first node
  • Under drought conditions: do not spray Varro herbicide if >35 days between seeding and spraying, as drought hastens crop development
  • Do not spray within three days before or after cold temperatures (3°C or lower)


Water Volumes
  • Ground – minimum of 5 US gal./ac. (19 L/ac.)
  • Aerial – minimum of 3 US gal./ac. (11 L/ac.)


  • One hour after application


Re-cropping Intervals
Safe to plant within 10 months following Varro application: alfalfa, barley, canary seed, canola, chickpeas, corn (field), dry bean, flax, lentils, mustard, oats (spring), peas (field), soybeans, sunflowers, timothy and wheat (spring, durum, and winter)


Residue and Grazing
Do not:
  • Graze the treated crop or cut for forage hay within 7 days or cut for hay within 30 days of application
  • Harvest wheat (spring or durum) for grain or straw within 60 days of application or winter wheat within 72 days of application
  • Re-enter treated fields within 12 hours of application


Resistance Management

Varro provides strong performance on grass weeds including Group 1-resistant wild oats and foxtail, making it an important part of your herbicide resistance management strategy.

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.

Types of herbicide resistance infographic.

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 are over 20 Group 1 herbicides on the market?

Development of Herbicide Resistance

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 infographic.
% 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 Groups, 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 rainfastness intervals
    • Time of day (herbicides are most effective when sprayed between 8:00am and 9:00pm)

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Herbicide resistance is everyone's problem. This product is a Mix It Up solution.

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