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Roundup WeatherMAX

Roundup WeatherMAX® herbicide is the preferred brand for growers who want unsurpassed performance to control their toughest weeds in tough conditions. You can count on Roundup WeatherMAX to perform and you can have confidence in your decision knowing that Bayer stands behind every jug with the Riskshield® protection package.

Product Summary

Product Type

Non-Selective Herbicide

Crops

  • Cereal Crops
  • Canola Crops
  • Corn Crops
  • Soybean Crops

Weeds Controlled

Annual Grasses
Perennial Grasses
Weeds
Broadleaf Weeds

See All Weeds

Groups & Active Ingredients

Group 9, Glyphosate

Formulation Type

Solution
540g/L formulation

Packaging

10 L Jug
115L Shuttle
450L Shuttle
800L Shuttle

riskshield protection package

When you use either Roundup WeatherMAX or Roundup Transorb HC herbicide you get the added peace-of-mind that comes with the Riskshield protection package.

Learn More   ▶

Crops

Pre Seed burn off Application

  • Prior to planting of all crops

In-Crop Application

  • Roundup Ready® crops. Roundup Ready Technology contain genes that confer tolerance to glyphosate.

Preharvest Application

  • Barley
  • Canola
  • Dry Beans
  • Flax
  • Lentils
  • Oats
  • Peas
  • Soybeans
  • Wheat

Postharvest Stubble Application Summer Fallow- Chemfallow

Effective Against

Weeds Controlled

  • Volunteer barley
  • Wild Oats
  • Cleavers
  • Flixweed
  • Shephard’s purse
  • Foxtail barley
  • Quackgrass
  • Canada thistle
  • Dandelion

See All Weeds Controlled

How to Apply

Where possible, rotate the use of Roundup WeatherMAX herbicide or other Group 9 herbicides within a growing season (sequence), or among growing seasons with different herbicide Groups that control the same weeds in a field.

Application rates for Roundup brand agricultural herbicides

540 g/L 10L JUG 115L SHUTTLE 450L SHUTTLE
0.33 L/ac. 30 acres 349 acres 1364 acres
0.50 L/ac. 20 acres 230 acres 900 acres
0.67 L/ac. 15 acres 172 acres 672 acres
0.83 L/ac. 12 acres 139 acres 542 acres
1.00 L/ac. 10 acres 115 acres 450 acres
1.17 L/ac. 9 acres 98 acres 385 acres
1.33 L/ac. 8 acres 86 acres 338 acres

Application Guidelines and Timing, Pre-harvest Application

Crops Percent Grain Moisture Visual Symptons
Barley/Oat/Wheat Less than 30% Hard dough stage; a thumbnail impression remains on seed
Canola Less than 30% Pods are green to yellow; most seeds are yellow to brown
Dry Beans Less than 30% Stems are green to brown in colour; pods are mature (yellow to brown in colour); 80% to 90% leaf drop (original leaves)
Flax Less than 30% Majority (75% to 80%) of boils are brown
Forages Not Applicable 3 to 7 days before last cut in final year of stand
Lentils Less than 30% Lowermost pods (bottom 15%) are brown and seeds rattle
Peas Less than 30% Majority (75% to 80%) of pods are brown
Soybeans Less than 30% Stems are green to brown in colour; pod tissue is dry and brown in appearance; 80% to 90% leaf drop

Apply 7-14 days before harvest to ensure best weed control.

Water Volumes and Tank Mixing

Water Volumes

For control of perennial weeds:

Apply Roundup WeatherMAX With Transorb 2 Technology in 20 to 40 L/ac. of clean water as a broadcast spray, using no more than 275 kPa pressure.

For control of annual weeds:

Apply Roundup WeatherMAX With Transorb 2 Technology in 20 to 40 L/ac. of clean water as a broadcast spray (except as otherwise stated on the label), using no more than 275 kPa pressure

Rainfastness

Rainfast 30 minutes after application

Tank Mixing Procedure

  • Fill spray tank three-quarters full of water
  • Start agitation and run for the entire mixing and spraying operation
  • Add required amount of the tank mix partner
  • Flush herbicide loading tank and herbicide containers with water
  • If using a herbicide loading system, ensure that the loading tank and lines to the pump are empty and flushed out with water before adding tank mix partner
  • Add required amount of Roundup WeatherMAX with Transorb 2 Technology
  • Flush herbicide loading tank and herbicide containers with water
  • If using a herbicide loading system, ensure that the loading tank and lines to the pump are flushed with water and empty before starting spray operation
  • Always start and end the mixing and spraying operation with a clean system

How to Apply on TruFlex™ Canola with Roundup Ready Technology

Rate and specific application instructions for weed control in TruFlex Roundup Ready canola varieties.

RATE (L/ac.) GROWTH STAGE OF CROP WEEDS CONTROLLED COMMENTS (Apply in 20 to 40 L/ac. of water)
0.22 to 0.33 Single application Emergence to first flower* Annual Grasses

Barnyard grass, green foxtail, volunteer barley, volunteer wheat, wild oats

Annual Broadleaves Chickweed, cleavers, corn spurry, cow cockle1, flixweed, hemp-nettle, kochia, lady’s-thumb, lamb’s quarters, narrow-leaved hawk’s beard, night-flowering catchfly1, non-Roundup Ready volunteer canola (rapeseed), redroot pigweed, Russian thistle, shepherd’s purse1, smartweed1, stinkweed, stork’s-bill, wild buckwheat, wild mustard, wild tomato

Perennials (Suppression) Canada thistle, dandelion, perennial sow thistle and dandelion

Perennials (Season-long control) Quackgrass

1The 0.22 L/ac. rate can be used for control of shepherd’s purse, cow cockle and night-flowering catchfly at the 1 to 3 leaf stage of the crop or for control of smartweed at the 4 to 6 leaf stage. Repeat applications may be required if a second flush of weeds germinate prior to canopy closure.
0.51 Single application Emergence to first flower* All the above weeds plus: Perennials (season-long control) Canada thistle, and perennial sow thistle
0.33 Sequential applications Emergence to first flower*

All the above weeds plus: Annual Broadleaves Round-leaved mallow

Perennials (season-long control) foxtail barley, Canada thistle

For sequential applications, ensure the crop has not advanced beyond the recommended growth stage.
0.67 Single application Emergence to first flower*

All the above weeds plus Biennial wormwood 2, cocklebur, common ragweed, crabgrass (smooth and large), eastern black nightshade, fall panicum, foxtail (yellow and giant), foxtail barley, Pennsylvania smartweed, smooth pigweed, velvet leaf, volunteer adzuki beans3, wild proso millet, wire-stem muhly

(Suppression only) Common milkweed, yellow nutsedge

2 Biennial wormwood should be at 2 to 8 leaf stage and actively growing.

3 For control of volunteer adzuki beans (unifoliate to the fourth trifoliate leaf stage) apply 0.67 L/ac. A second 0.67 L/ac. application may be used for late flushes emerging after the initial treatment. Adzuki beans should be at unifoliate to fourth trifoliate leaf stage and actively growing.

0.67 Sequential applications Emergence to first flower*

All the above weeds plus: Perennials (season-long control) Bur cucumber, common milkweed, dandelion, field bindweed, horse nettle, tall waterhemp, yellow nutsedge

A sequential application may be made at least 2 weeks after the first application.

A second 0.67 L/ac. application may be used for late weed flushes emerging after the initial treatment.

Common milkweed should be 15-60 cm in height and actively growing.

Yellow nutsedge should be 5-15 cm in height and actively growing.

Horse nettle (2 to 12-leaf stage).

Tall waterhemp up to and including the 18 leaf stage.

Bur Cucumber from the 1-to-18 leaf stage.

1.33 Single application Emergence to 6 leaf All the above weeds One application allowed in crop per season.

*When 50% of the plants in the field have more than one flower.

  • Ensure the crop has not advanced beyond the recommended growth stage for all applications.
  • Repeat applications may be required if a second flush of weeds germinates prior to canopy closure.
  • Maximum 1.33 L/ac. is allowed for the post emergence use.

How to Manage Resistance

For resistance management, Roundup WeatherMAX with Transorb 2 Technology Liquid Herbicide is a Group 9 herbicide. Any weed population may contain or develop plants naturally resistant to Roundup WeatherMAX with Transorb 2 Technology Liquid Herbicide and other Group 9 herbicides. The resistant biotypes may dominate the weed population if these herbicides are used repeatedly in the same field. Other resistance mechanisms that are not linked to site of action, but specific for individual chemicals, such as enhanced metabolism, may also exist. Appropriate resistance management strategies should be followed.

Mix Groups

Use tank mixtures with herbicides from a different Group when such use is permitted. To delay resistance, the less resistance-prone partner should control the target weed(s) as effectively as the more resistance-prone partner.

Herbicide use should be based on an integrated weed management program that includes scouting, historical information related to herbicide use and crop rotation, tillage (or other mechanical control methods), cultural (for example, higher crop seeding rates; precision fertilizer application method and timing that favors crop and not weeds), biological (weed-competitive crops or varieties) and other management practices. Weed size should also be considered, as the product is more effective on smaller weeds.

Monitor weed populations

After herbicide application check weeds in your fields for signs of resistance development (for example, one weed species on the herbicide label may not be controlled). If resistance is suspected, prevent weed seed production in the affected area if possible, by using an alternative herbicide from a different Group. Prevent movement of resistant weed seeds to other fields by cleaning harvesting and tillage equipment when moving between fields, and always plant clean seed.

Have suspected resistant weed seeds tested by a qualified laboratory to confirm resistance and identify alternative herbicide options.

Advice

Contact your local extension specialist, certified crop advisor, or Bayer at 1-888-283-6847 for any additional pesticide resistance-management and/or integrated weed-management recommendations for specific crops and weed biotypes.

For more information on weed resistance management visit https://www.mixitup.ca.

Provinces of Registration

  • Alberta
  • British Columbia
  • Manitoba
  • New Brunswick
  • Newfoundland and Labrador
  • Nova Scotia
  • Ontario
  • Prince Edward Island
  • Quebec
  • Saskatchewan
  • Northwest Territories
  • Yukon
  • Nunavut
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