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Corvus Herbicide

Corvus® herbicide is a corn herbicide for Eastern Canadian farmers that provides outstanding control of a broad spectrum of broadleaf and grass weeds in field and seed corn.

Corvus offers flexibility in application timing and tank mixing options to tailor your weed control to your needs, so you can get outstanding performance.

Corn Crop Protection Guide

Product Summary

Product type icon

Product Type

Herbicide

Corn crop icon

Crops

Field corn

Seed corn

Weeds controlled icon

Weeds Controlled

Crabgrass (hairy/large, smooth)*

Common ragweed*

Waterhemp (common, tall)*

Groups and active ingredients icon

Groups & Active Ingredients

Thiencarbazone-methyl (Group 2)

Isoxaflutole (Group 27)

Formulation type icon

Formulation Type

Suspension concentrate

Packaging icon

Packaging

4 x 4.0 L jugs (a jug treats 30 ac. at the recommended mid-rate)

Product Highlights

Corvus herbicide provides outstanding control of a broad spectrum of broadleaf and grass weeds in corn.

  • Delivers three levels of control to fight weeds: rapid burndown for emerged weeds, residual control to prevent newly emerging weeds and reactivation with rain for prolonged weed control
  • Offers flexibility in application timing as it can be applied pre-emerge, pre-plant incorporated, or early post-emerge (up to 2 leaf)
  • Excellent resistance management tool and tank-mix partner with Roundup® brands

Performance

Weed Control – Corvus Performs

28 Days After Pre-emerge Application

Percent Control
0 10 20 30 40 50 60 70 80 90 100

Corvus (0.33 L/ha)

81

Primextra® II Magnum® herbicide (3.5 L/ha)

79

Integrity® herbicide (1.1 L/ha)

81

Engarde™ herbicide (348 g/ha)

75

Corvus (0.33 L/ha) + atrazine

92

Acuron® herbicide (5 L/ha)

86

Source: 2021-2023 Eastern Canada Market Development trials (27 locations). A total of 101 weed hits, 68 broadleaves and 33 grasses. Predominate species being lamb’s-quarters (23), redroot pigweed (13) and yellow foxtail (6). Treatment means are significantly different at P≤0.05. Your results may vary according to agronomic, environmental and pest variables.   

Crops

  • Field corn
  • Seed corn

Weeds Controlled

Grassy weeds controlled:

  • Barnyard grass*,1
  • Crabgrass (hairy/large, smooth)*
  • Foxtail (giant, green, yellow)*,1
  • Witchgrass*

Broadleaf weeds controlled:

  • Common ragweed*
  • Dandelion (seedling)*
  • Eastern black nightshade*
  • Hairy galinsoga*
  • Lamb's-quarters*
  • Mustard (wild, wormseed)*
  • Plantain (seedling)*
  • Redroot pigweed*
  • Sowthistle (annual, spiny annual)*
  • Waterhemp (common, tall)*
  • Velvetleaf*

*Including emerged weeds up to 5 cm in height; includes ALS/SU (Group 2), auxin (Group 4), triazine (Group 5), glyphosate (Group 9) and PPO (Group 14)-resistant biotypes

1 Non- ALS/SU (Group 2) resistant biotypes only

How to Apply

  • Always read and follow label directions
  • Apply Corvus alone or in tank mixtures, by ground equipment only. Do not apply with aerial application equipment.
  • Accurately calibrate the sprayer prior to mixing the herbicide treatments
  • Apply Corvus in a minimum of 150 L/ha (15 gal./ac.) of total spray volume. Sprayable fluid fertilizer (nitrogen solution) may replace all or part of the water as a carrier for pre-plant (surface or incorporated) and pre-emergence applications.
  • Refer to the nozzle manufacturer’s recommendations for proper nozzle, pressure setting and sprayer speed for optimum product performance and minimal spray drift
  • For best results use flat fan nozzles or comparable nozzles to achieve uniform spray distribution.  Do not apply with hollow cone nozzles or with other application equipment which does not provide uniform coverage.
  • Agitate thoroughly before and during application with either bypass or mechanical agitation

Re-crop Interval

Immediate plant back Corn (field, seed)
4 months after a spring application of Corvus Wheat (winter)
Year following an application of Corvus Barley (spring)
Corn (field, seed)
Soybeans
Wheat (spring)

Application Rates and Guidelines

LOW RATE (jug treats 43 ac.)

  • 230 mL/ha (93 mL/ac.)  
    • Early-season control
    • Use in situations of low weed pressure and in a planned two-pass system 

MID RATE (jug treats 30 ac.)

  • 330 mL/ha (133 mL/ac.)
    • Our recommended rate for PPI, PRE and EPOST programs

HIGH RATE (jug treats 24 ac.)

  • 410 mL/ha (166 mL/ac.)
    • Use in situations of heavy weed pressure
    • Will provide improved (over lower rates) control of tall waterhemp, large crabgrass and green foxtail

Pre-plant/pre emergence burndown spray additives:

  • For control of emerged weeds prior to corn emergence, Corvus may be used in conjunction with an adjuvant: COC or MSO applied at 1% volume/volume or a non-ionic surfactant (NIS), such as Agral® 90 or Agsurf®, applied at 0.25% volume/volume

Early post emergence to corn:

  • If applying early post emergence to corn, do not use any adjuvants with Corvus
  • Refer to the product label for any post-emergent applications

Pre-Harvest, Grazing/Feeding and Re-entry Intervals

  • Do not graze or feed the immature corn to livestock prior to 45 days of Corvus application
  • If tank mixing, always respect the maximum pre-harvest/-grazing interval stated on the labels of all the tank-mix products
  • Do not enter or allow re-entry into treated areas until 12 hours after application. Exception: If the product is soil-injected or soil-incorporated, workers may enter the treated area if there will be no contact with anything that has been treated.

Application Tips

  • Plant corn at least 4 cm deep. Failure to close the seed furrow may allow herbicide spray to directly contact the seed which can cause injury.
  • Corvus treatments are most effective in controlling weeds when adequate rainfall is received within 14 days after application
  • For ground application:
    • For best results use flat fan nozzles or comparable nozzles to achieve uniform spray distribution. Do not apply with hollow cone nozzles or with other application equipment which does not provide uniform coverage.
    • Apply Corvus in a minimum of 150 L/ha (15 gal./ac.) of total spray volume. Sprayable fluid fertilizer (nitrogen solution) may replace all or part of the water as a carrier for pre-plant (surface or incorporated) and pre-emergence applications.
    • Accurately calibrate the sprayer prior to mixing the herbicide treatments
  • Do not use sprayable fluid fertilizer (nitrogen solution) as the carrier for early post emergence applications as the nitrogen solution can typically cause corn injury such as tissue burn (necrosis)
  • Do not use any adjuvants with Corvus when applied to emerged field corn
  • Do not apply Corvus to field corn grown on loamy sands or sands and/or soils with less than 2% O.M.

Water Volumes and Tank Mixing

Water Volumes

Corvus herbicide can be applied broadcast in a minimum of 150 L/ha (15 gal./ac.) of total spray volume. Sprayable fluid fertilizer (nitrogen solution) may replace all or part of the water as a carrier for pre-plant (surface or incorporated) and pre-emergence applications.

Rainfastness

Rainfast 2 hours after application

Tank Mixing Procedure

Refer to product label





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




Tank Mix Flexibility

Corvus is an ideal tank-mix partner for:

  • Atrazine
  • Roundup® Transorb® HC liquid herbicide1
  • Roundup WeatherMAX® with Transorb® 2 Technology liquid herbicide1
  • Roundup Xtend® herbicide with VaporGrip® Technology1,2
  • Roundup Xtend 2 herbicide with VaporGrip Technology1,2
  • XtendiMax® herbicide with VaporGrip® Technology2
  • XtendiMax 2 herbicide with VaporGrip Technology2

1Use in corn hybrids with Roundup Ready® 2 Technology only

2Do not tank mix these products with UAN or an additional adjuvant

How to Manage Resistance

Resistance Management

Please note that Corvus is both a Group 2 and a Group 27 herbicide. Any weed population may contain or develop plants naturally resistant to Group 2 and/or Group 27 herbicides.

To Delay Herbicide Resistance:

Where possible, rotate the use of Corvus or other Group 2 and/or 27 herbicides within a growing season (sequence) or among growing seasons with different herbicide groups that control the same weeds in a field.

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, and considers tillage (or other mechanical control methods), cultural for example, higher crop seeding rates; precision fertilizer application method and timing to favour the crop and not the weeds, biological (weed-competitive crops or varieties) and other management practices.

Monitor Weed Populations

After all herbicide applications 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 an alternative herbicide from a different group. Prevent movement of resistant weed seeds to other fields by cleaning harvesting and tillage equipment and planting 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 or certified crop advisors for any additional pesticide resistance-management and/or integrated weed-management recommendations for specific crops and weed biotypes.

For further information or to report suspected resistance contact Bayer via phone at 1-888-283-6847.

Provinces of Registration

  • New Brunswick
  • Newfoundland
  • Nova Scotia
  • Ontario
  • Prince Edward Island
  • Quebec
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