Herbicide Recommendations for Corn: Postemergence Broadleaf Herbicides and Tank-Mixes (for Broadleaf Weed Control)
Excerpt from 2010-11 Chapter 9, Publication 75, Guide to Weed Control, Order this publication
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Table
of Contents| Trade Name | |
|---|---|
| Active Ingredient | 2,4-D* |
| Formulation | 470 g/L |
| Rate per hectare (active) | 0.28 to 0.56 kg/ha |
| Rate per hectare (product) | 0.6 to 1.2 L/ha |
| Rate per acre (product) | 0.24 to 0.48 L/ac |
*See Table 4-1, Herbicides Used in Ontario, for formulations available. See label for specific uses and rates.
Precautions
- Do NOT use on seed corn or sweet corn.
- Apply as an overall spray until corn is 15 cm high (leaf extended); thereafter, use drop nozzles. Use amine formulation.
- See special notes on postemergence use of 2,4-D and related hormone chemicals.
- Do NOT add oil or surfactants.
Precautions
- For increased activity and extended period of activity, apply in an oil water emulsion of 10 to 17 L/ha (4 to 6.8 L/ac) of emulsifiable light mineral oil and 150-200 L/ha water (60-80 L/ac). Apply when most weeds have emerged. The low rate can be used successfully with later cultivation.
| Trade Name | Atrazine 480 | + Buctril M | or + Badge or Logic M or Mextrol |
|---|---|---|---|
| Active Ingredient |
atrazine
|
+ bromoxynil/ MCPA
|
or + bromoxynil/ MCPA
|
| Formulation |
480 g/L
|
560 g/L (1:1)
|
450 g/L (1:1)
|
| Rate per hectare (active) |
1.1 to 1.49 kg/ha
|
0.56 kg/ha
|
0.56 kg/ha
|
| Rate per hectare (product) |
2.29 to 3.1 L/ha
|
1 L/ha
|
1.25 L/ha
|
| Rate per acre (product) |
0.96 to 1.24 L/ac
|
0.4 L/ac
|
0.5 L/ac
|
Precautions
- Do NOT use on seed corn or sweet corn.
- Apply from the 4-6 leaf stage of corn but injury may occur if applied after the 6-leaf stage.
- Controls a wider spectrum of broadleaf weeds than bromoxynil/ MCPA alone; larger velvetleaf will be controlled.
- Do NOT add oil or surfactant.
- Do NOT use formulated atrazine/oil products in this tank-mixture.
Precautions
- Do NOT use on seed corn or sweet corn.
- This treatment will provide good to excellent control of broadleaf weeds including those triazine resistant and velvetleaf. Use the higher rate for residual control
- See special notes for corn regarding dicamba applications and precautions for Banvel II or Oracle alone POST.
Precautions
- Do NOT use on seed corn or sweet corn.
- Application of the lower rate can be made up to 20 cm standing corn. Use drop pipes when corn is 20-50 cm tall. The 0.6 kg/ha rate commonly referred to as the overlay treatment is particularly effective in controlling velvetleaf and providing extended residual control of other late germinating deep rooted broadleaf annuals and can be applied from the spike stage to the 5-leaf stage (13 cm standing corn).
- See special notes on postemergence use of dicamba and related hormone chemicals.
- Do NOT use dicamba if temperature exceeds 25°C at the time of application, or if high humidity is expected, due to the possibility of dicamba volatilizing and injury to susceptible crops nearby.
- Do NOT add oil or surfactant.
| Trade Name | Banvel II or Oracle | + 2,4-D |
|---|---|---|
| Active Ingredient |
dicamba
|
+ 2,4-D*
|
| Formulation |
480 g/L
|
470 g/L
|
| Rate per hectare (active) |
0.14 kg/ha
|
0.4 kg/ha
|
| Rate per hectare (product) |
0.29 L/ha
|
0.85 L/ha
|
| Rate per acre (product) |
0.12 L/ac
|
0.34 L/ac
|
*See Table 4-1, Herbicides Used in Ontario, for formulations available. See label for specific uses and rates.
Precautions
- Do NOT use on seed corn or sweet corn.
- Application can be made up to 10 cm standing corn. Use drop pipes when corn is 10-50 cm tall. Use amine formulation of 2,4-D.
- See special notes on postemergence use of dicamba and 2,4-D and related hormone chemicals.
- Do NOT add oil or surfactant.
| Trade Name | Basagran Forté | + Oil Concentrate |
|---|---|---|
| Active Ingredient |
bentazon
|
+ oil concentrate
|
| Formulation |
480 g/L
|
|
| Rate per hectare (active) |
0.84 to 1.08 kg/ha
|
2 L/ha
|
| Rate per hectare (product) |
1.75 to 2.25 L/ha
|
|
| Rate per acre (product) |
0.7 to 0.9 L/ac
|
|
Precautions
- Top growth of nutsedge and Canada thistle are controlled and field bindweed may be suppressed by 2 applications of 1.75 L/ha (0.7 L/ac) (0.84 kg active/ha) applied 10 days apart.
- Cool weather or drought may delay control.
| Trade Name | Buctril M | or Badge or Logic M or Mextrol |
|---|---|---|
| Active Ingredient |
bromoxynil/ MCPA
|
or bromoxynil/ MCPA
|
| Formulation |
560 g/L (1:1)
|
450 g/L (1:1)
|
| Rate per hectare (active) |
0.558 kg/ha
|
0.558 kg/ha
|
| Rate per hectare (product) |
1 L/ha
|
1.25 L/ha
|
| Rate per acre (product) |
0.4 L/ac
|
0.5 L/ac
|
Precautions
- Do NOT use on seed corn or sweet corn.
- Apply from the 4-6 leaf stage of corn but injury may occur if applied after the 6-leaf stage.
- Controls most annual broadleaf weeds up to the 4-leaf stage (lamb's-quarters and mustards to 8-leaf stage).
- Use in preference to Pardner or Koril when wild mustard is a particular problem.
| Trade Name | Callisto | + Aatrex Liquid | + non-ionic surfactant |
|---|---|---|---|
| Active Ingredient |
mesotrione
|
+ atrazine
|
+ non-ionic surfactant
|
| Formulation |
480 g/L
|
480 g/L
|
|
| Rate per hectare (active) |
0.1 kg/ha
|
0.28 kg/ha
|
0.2% v/v
|
| Rate per hectare (product) |
0.21 L/ha
|
0.58 L/ha
|
2 L/1000 L
|
| Rate per acre (product) |
0.085 L/ac
|
0.235 L/ac
|
2 L/1000 L
|
Precautions
- Apply from the 3 to 8 leaf stage of field corn.
- Apply from the 3-6 leaf stage of seed or sweet corn.
- Do NOT apply to Delmonte 2038 sweet corn.
- Do NOT harvest sweet corn within 50 days of treatment.
- Seed corn inbred and sweet corn varieties vary in their tolerance to CALLISTO, consult your seed supplier for more information.
- Apply in 100-200 L/ha of water.
- Do NOT apply to corn treated with an organophosphorous
insecticide.
| Trade Name | Distinct | + non-ionic surfactant | + liquid urea ammonium nitrate (UAN) |
|---|---|---|---|
| Active Ingredient |
diflufenzopyr/ dicamba
|
+ non-ionic surfactant
|
+ liquid urea ammonium nitrate
|
| Formulation |
70 WG
|
|
|
| Rate per hectare (active) |
0.2 kg/ha
|
0.25% v/v
|
1.25% v/v
|
| Rate per hectare (product) |
0.285 kg/ha
|
2.5 L/1000 L
|
12.5 L/1000 L
|
| Rate per acre (product) |
0.115 kg/ac
|
2.5 L/1000 L
|
12.5 L/1000 L
|
Precautions
- Do NOT use on seed corn or sweet corn.
- Apply to actively growing weeds when corn is in the 2-6 leaf stage.
- Apply when temperatures above 4°C are predicted for the 24 hours before and after application.
Precautions
- Do NOT use on seed corn or sweet corn.
- See special notes on postemergence use of 2,4-DB and related hormone chemicals.
- Note: The maximum label rate for Embutox 625 is 2.25 L/ha (0.9 L/ac) of product.
- Do NOT add oil or surfactant.
*See Table 4-1, Herbicides Used in Ontario, for formulations available. See label for specific uses and rates.
Precautions
- Apply to emerged grassy (up to 4 leaf) and broadleaf (up to 8 leaf) weeds.
- Apply between the spike and 7 leaf stage of seed, sweet and field corn.
- For seed and sweet corn, Assist should be used instead of Merge at a rate of 12.5 L/2,000 L. The use of Merge will increase the risk of crop injury to seed and sweet corn.
| Trade Name | Laddok | + Assist |
|---|---|---|
| Active Ingredient |
bentazon/atrazine
|
+ oil concentrate
|
| Formulation |
400 g/L (1:1)
|
|
| Rate per hectare (active) |
0.8 to 1.6 kg/ha
|
2 L/ha
|
| Rate per hectare (product) |
2 to 4 L/ac
|
2 L/ha
|
| Rate per acre (product) |
0.8 to 1.6 L/ac
|
0.8 L/ac
|
Precautions
- The recommended rate of 1.2 to 1.6 kg/ha of Laddok (3 to 4 L/ha (1.2 to 1.6 L/ac)).
- Laddok may be reduced to 0.8 to 1 kg/ha (2 to 2.5 L/ha (0.8 to 1 L/ac)).
- If Frontier or Dual II Magnum has been applied at the recommended rate for preemergence grass control, use Laddok at 3 to 4 L/ha (1.2 to 1.6 L/ac) for nutsedge control; repeat 7-10 days if necessary.
| Trade Name |
Marksman
or Propero
|
|---|---|
| Active Ingredient | dicamba/atrazine |
| Formulation | 393 g/L |
| Rate per hectare (active) | 1.48 to 1.8 kg/ha |
| Rate per hectare (product) | 3.7 to 4.5 L/ha |
| Rate per acre (product) | 1.5 to 1.8 L/ac |
Precautions
- Do NOT use on seed corn or sweet corn.
- Application can be made up to 13 cm standing corn (5-leaf). Use the lower rate on coarse textured soils and the higher rate on medium to fine textured soils.
- See special notes on postemergence use of dicamba and related hormone chemicals.
| Trade Name | |
|---|---|
| Active Ingredient | MCPA |
| Formulation | 500 g/L* |
| Rate per hectare (active) | 0.38 to 0.63 kg/ha |
| Rate per hectare (product) | 0.76 to 1.26 L/ha |
| Rate per acre (product) | 0.3 to 0.5 L/ac |
*See Table 4-1, Herbicides Used in Ontario, for formulations available. See label for specific uses and rates.
Precautions
- Do NOT use on seed corn or sweet corn.
- Treat before the corn reaches 15 cm tall (leaf extended).
- Use the lower rate for small, actively growing weeds and the higher rate for larger weeds or under adverse weather conditions.
- Top growth control of fully developed horsetail (15-25 cm) can be achieved with 1 L/ha (0.4 L/ac) of product.
| Trade Name | Pardner | or Koril, Brotex |
|---|---|---|
| Active Ingredient |
bromoxynil
|
or bromoxynil
|
| Formulation |
280 g/L
|
235 g/L
|
| Rate per hectare (active) |
0.28 to 0.34 kg/ha
|
0.28 to 0.34 kg/ha
|
| Rate per hectare (product) |
1 to 1.2 L/ha
|
1.2 to 1.4 L/ha
|
| Rate per acre (product) |
0.4 to 0.48 L/ac
|
0.48 to 0.56 L/ac
|
Precautions
- Controls most annual broadleaf weeds, including triazine resistant species at the 1-4 leaf stage.
- Pardner and Koril are contact herbicides and are non volatile.
- Do NOT use Brotex on seed or sweet corn.
| Trade Name | Pardner | or Koril | + Banvel II |
|---|---|---|---|
| Active Ingredient |
bromoxynil
|
or bromoxynil
|
+ dicamba
|
| Formulation |
280 g/L
|
235 g/L
|
480 g/L
|
| Rate per hectare (active) |
0.28 kg/ha
|
0.28 kg/ha
|
0.144 kg/ha
|
| Rate per hectare (product) |
1 L/ha
|
1.2 L/ha
|
0.3 L/ha
|
| Rate per acre (product) |
0.4 L/ac
|
0.48 L/ac
|
0.12 L/ac
|
Precautions
- Do NOT use on seed corn or sweet corn.
- Apply when the corn is in the 4-6 leaf stage as an overall treatment and up to 50 cm standing corn, using drop pipes.
- Controls most annual broadleaf weeds including triazine resistant lamb's-quarters, pigweed and ragweed up to the 6-leaf stage.
- See special notes on postemergence use of dicamba and precautions for Banvel II alone POST.
| Trade Name | Peakplus1 (Peak) | + Banvel II | + non-ionic surfactant |
|---|---|---|---|
| Active Ingredient |
prosulfuron + dicamba
|
prosulfuron + dicamba
|
+ non-ionic surfactant
|
| Formulation |
75 WG
|
+ 480 g/L
|
|
| Rate per hectare (active) |
10 g/ha
|
+ 0.14 kg/ha
|
0.2% v/v
|
| Rate per hectare (product) |
13.3 g/ha
|
+ 0.3 L/ha
|
2 L/1000 L
|
| Rate per acre (product) |
5.3 g/ac
|
+ 0.12 L/ac
|
2 L/1000 L
|
Precautions
- Do NOT apply to sweet corn.
- Apply when the corn is in the 2-7 leaf stage.
- Controls most annual broadleaf weeds including triazine resistant lamb's-quarters and pigweed up to the 6-leaf stage; cocklebur and velvetleaf up to the 6-leaf stage; and ragweed up to the 8-leaf stage.
- Do NOT apply to corn treated with organophosphorus insecticides.
- Peakplus1 is a co-pack of Peak 75WG and Banvel II.
1 - Indicates product sold as co-pack under this name.
Precautions
- Do NOT use on seed corn or sweet corn.
- Apply as an overall spray from the spike to the 4-leaf stage of corn.
- Do NOT add oil or surfactant.
| Trade Name | Tropotox Plus | or Clovitox Plus | or Topside |
|---|---|---|---|
| Active Ingredient |
MCPB/MCPA (15:1)
|
or MCPB/MCPA (15:1)
|
or MCPB/MCPA (15:1)
|
| Formulation |
400 g/L
|
400 g/L
|
400 g/L
|
| Rate per hectare (active) |
1.1 to 1.7 kg/ha
|
1.1 to 1.7 kg/ha
|
1.1 to 1.7 kg/ha
|
| Rate per hectare (product) |
2.75 to 4.25 L/ha
|
2.75 to 4.25 L/ha
|
2.75 to 4.25 L/ha
|
| Rate per acre (product) |
1.1 to 1.7 L/ac
|
1.1 to 1.7 L/ac
|
1.1 to 1.7 L/ac
|
Precautions
- Do NOT use on seed corn or sweet corn.
- Apply when corn is 30-60 cm high, using drop pipes. Some control of field horsetail may be obtained with the higher rates of MCPB/MCPA.
- See special notes on postemergence use of MCPB/MCPA and related hormone chemicals.
- Do NOT add oil or surfactant.
Related Links
- Weeds in Ontario
- Corn in Ontario
- Problem Weed Control in Field Crops
- Pesticide Application and Safety
- Pesticide Companies and Agents
- OMAFRA Sprayer Calibration Calculator
- Search the PMRA website
- OMAFRA Publication 505: Ontario Weeds
- OMAFRA Publication 75: Guide To Weed Control
For more information:
Toll Free: 1-877-424-1300
Local: (519) 826-4047
E-mail: ag.info.omafra@ontario.ca
| Author: | OMAFRA Staff |
|---|---|
| Creation Date: | 25 November 2002 |
| Last Reviewed: | 30 January 2010 |