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Martinsville, Ohio | 34
Corn Herbicide Management Strategies
Preemergence herbicide programs have long been the mainstay of weed management in corn, due in large part to the low cost
of atrazine and its broad spectrum of control. A total preemergence approach can still be effective in fields with low to moderate
populations of most annual weeds. The commonly used premix of atrazine plus an acetamide herbicide (Bicep II Magnum,
Degree Xtra, FulTime, etc) can be supplemented as necessary with Balance, Python, Hornet, or simazine to improve control
of weeds such as fall panicum, triazine-resistant lambsquarters, and velvetleaf. However, all of these tank-mix partners except
simazine can occaionally injure corn, especially when corn is planted too shallow, on coarse-textured soils, and when cold, wet
conditions occur after planting. In fields with moderate to high weed populations, a preemergence plus postemergence approach
will provide more consistent control with less risk of corn injury. A number of options are available for this type of program at
a reasonable cost. A preemergence plus postemergence approach is especially effective in fields with giant ragweed, burcucumber,
moderate to high annual populations of anual grass, velvetleaf, and triazine-resistant lambsquarters, and perennial weeds. A
number of effective total postemergence herbicide programs are also available. However, research indicates that total postemergence
programs lacking residual activity should be used only in fields with low weed populations. A total postemergence herbicide
program should be applied before most weeds in a field exceed 4 to 6 inches in height, and reinfestation with later-emerging
weeds is likely if a herbicide with residual activity is not included. Using a postemergence program that has substantial residual
activity allows more flexibility in the window of application. Herbicides can be applied when weeds are anywhere from 2 to 5
inches tall, since the residual component will control weeds that emerge after application.
Preemergence Corn Herbicide Programs
Total preemergence (PRE) herbicide programs fit fields with:
• low to moderate annual grass populations
• low giant ragweed populations
• any population of most annual broadleaf weeds
Total preemergence programs do not fit fields with:
• high grass populations
• moderate to high giant ragweed, cocklebur, velvetleaf, and annual morningglory populations
• perennial weeds
• burcucumber
Advantages of PRE programs:
• one-pass, can apply while planting
• with adequate rain, provides control through the first 6 weeks, and later-emerging weeds have much reduced impact on corn
yield
• effective on many annual grass and broadleaf weeds
Disadvantages of PRE programs:
• dependence upon adequate rain within narrow period of time
• not effective enough on tough broadleaf or perennial weeds or in high grass populations
• corn needs to be competitive earlier in season compared to PRE plus POST programs
Approaches:
Atrazine premix products (Bicep, Harness Xtra, etc) or similar mixes are effective broad-spectrum treatments for fields suited to
total preemergence.
• can add simazine or Balance to improve grass control (or use a mixture of Epic + atrazine)
• can add reduced rate of Balance to boost consistency under low rainfall conditions
• can add Balance, Callisto, Python, or Hornet to improve triazine-resistant lambsquarters, giant ragweed, and velvetleaf control
• atrazine rates of 1.5 to 2 lb/A can improve control of velvetleaf and giant ragweed. Some premix products have less than 1.5
lbs/A
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In low to moderate grass populations with adequate rain, preemergence grass herbicides are comparable in their effectiveness,
especially when mixed with atrazine. However, differences show occasionally in OSU research:
For longevity of grass control:
s-metolachlor/metolachor > Degree Xtra > FulTime = Keystone = Guardsman Max = Axiom+atrazine = Define+atrazine >
Harness Xtra > Balance
Amount of rain needed for activity:
Balance < Harness Xtra = FulTime = Keystone < Guardsman Max = Degree Xtra < Define+atrazine = Axiom+atrazine =
metolachlor/s-metolachlor
Preemergence plus Postemergence Corn Herbicide Programs
Preemergence (PRE) plus Postemergence (POST) herbicide programs fit any field, but are especially well-suited
for fields with:
• moderate to high annual grass populations
• moderate to high giant ragweed, cocklebur, velvetleaf, and annual morningglory populations
• perennial weeds
• burcucumber
Advantages of PRE plus POST programs:
• very consistent, as long as some rain on PRE
• creates wider window for POST application, compared to total POST programs
• good on many tough weeds
Disdvantages of PRE plus POST programs:
• dependence upon rain for PRE activity (although have planned POST backup)
• two-pass
• cost
Approaches:
In fields with low to moderate grass populations, can take an approach of preemergence grass herbicide followed by postemergence
broadleaf herbicide (without much grass activity). Examples:
• Outlook followed by dicamba+atrazine
• TopNotch followed by Hornet + Clarity
To provide postemergence control of a few grass escapes, can take an approach of a preemergence grass herbicide followed by a
postemergence broadleaf herbicide that also has activity on small grasses. Examples:
• Dual II Magnum followed by NorthStar or Celebrity Plus
• Outlook followed by Distinct + atrazine
• Harness followed by Marksman
In fields with moderate to high grass and/or problem broadleaf populations, can take an approach of preemergence grass or
grass+broadleaf herbicide (full or reduced rate) followed by broad-spectrum postemergence herbicide with grass and broadleaf
activity. Examples:
• Cinch ATZ followed by Steadfast ATZ
• atrazine and/or simazine followed by Lightning + Distinct (Clearfield corn)
• atrazine + simazine followed by Liberty (Liberty Link corn)
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• Harness Xtra followed by glyphosate (RR corn)
• Bicep followed by Spirit + Accent
• Balance + atrazine followed by Equip
Total Postemergence Corn Herbicide Programs (without residual)
Total postemergence (POST) herbicide programs that do not provide residual control should be used primarily
in fields with:
• low annual grass populations
• low to moderate annual broadleaf populations
Avoid use in fields with:
• moderate to high annual grass populations
• high broadleaf populations
• burcucumber
• perennial broadleaf weeds (might emerge too late for control)
Advantages of total POST without residual:
• one-pass, can plant first and apply later
• not dependent upon rainfall for activity (although soil moisture status affects weed response to herbicides)
Disadvantages or total POST without residual:
• narrow window of application should be applied before weeds exceed 4 inches in height to avoid yield loss
• lack of control of weeds that emerge after application
• application too early for best perennial weed control
Approaches:
In fields with low weed pressure, can make a single postemergence application of herbicides without residual. Examples:
• Accent + Clarity
• Option + Distinct
• Celebrity Plus
• Glyphosate (RR corn)
• Liberty (Liberty Link corn)
Total Postemergence Corn Herbicide Programs (with residual)
Total postemergence (POST) herbicide programs that provide substantial residual control can be used in fields
with:
• most annual weed populations
Avoid use in fields with:
• perennial broadleaf weeds (might emerge too late for control)
• high giant ragweed and annual grass populations
Advantages of total POST with residual:
• one-pass, can plant first and apply later
• not dependent upon rainfall for postemergence activity (although soil moisture status affects weed response to herbicides)
• consistent control of many annual weed populations
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Disadvantages of total POST with residual:
• should be applied before weeds exceed 4 inches in height to avoid yield loss
• application too early for best perennial weed control
• need rain within 2 weeks of application for residual activity
Approaches:
Can make a single postemergence application before weeds exceed 4 inches in height with mix of postemergence herbicides with
grass and broadleaf activity and residual herbicides with primarily broadleaf activity (if grass population not high). Examples:
• Liberty ATZ (Liberty Link corn)
• ReadyMaster ATZ (RR corn)
• Accent + Marksman
• Option + Marksman or atrazine
In fields with moderate to high grass pressure, may need residual component with more activity on grasses than those listed
above. Examples:
• Glyphosate + Degree Xtra (RR corn)
• Lightning + atrazine (Clearfield corn)
• Liberty + atrazine/chloroacetamide premix (Liberty Link corn)
The following examples have limited soil residual, but residual may not be broad-spectrum or long enough in fields with moderate
to high weed populations:
• Steadfast ATZ
• Basis Gold + Clarity
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Table 5. Weed Response to Herbicides in Corn
This table compares the relative effectiveness of herbicides on individual weeds. Ratings are based on labeled application rate and
weed size or growth stage. Performance may be better or worse than indicated in the table, due to weather or soil conditions or other
variables.
Weed control rating: Crop tolerance rating:
9 = 90% to 100% control 0 = Excellent
8 = 80% to 90% control 1 = Good
7 = 70% to 80% control 2 = Fair
6 = 60% to 70% control 3 = Poor
- = insufficent data
Weed control rating of 5 or less is rarely significant. Crop injury of 1 or less is rarely significant.
Grasses Broadleaf Weeds
Rhizome Johnsongrass
Quackgrass
Yellow Nutsedge
Black Nightshade
Burcucumber
Cocklebur
Common Ragweed
Shattercane
Seedling Johnsongrass
Giant Ragweed
Annual Morningglory
Yellow Foxtail
Giant Foxtail
Fall Panicum
Crabgrass
Barnyardgrass
Crop Tolerance
Mode of Action
Jimsonweed
Pigweed (redroot)
Velvetleaf
Smartweed
Triazine-Resistant Lambsquarters
Lambsquarters
ALS-resistant common ragweed
ALS-resistant giant ragweed
Preplant or Preemergence
Preemergence
Acetochlor1 S 1 9 9 8 9 9 5 4 0 0 8+ 0 8+ 0 0 7 7 2 2 4 7+ 7+ 8+ 5 3 8
Acetochlor+atrazine1 S/P 1 9 9 8 9 9 5 4 0 6 8+ 8 9 6 8 9 9 8 8 9 9 7+ 9 9 8 9
Alachlor1 S 1 8 8+ 8 8+ 8+ 5 4 0 0 8 0 8+ 0 0 5 5 2 2 4 6 6 8 4 0 8
Alachlor + atrazine1 S/P 1 9 8+ 8 8+ 8+ 5 4 0 6 8 8 9 6 8 9 9 8 8 9 9 6 9 9 8 9
Atrazine P 0 8 5 3 7 7 2 0 0 8 7 8 9 6 8 9 9 8 8 9 9 0 9 9 8 9
Axiom S/P 1 8 8+ 8 8+ 8+ 5 4 0 0 6 3 8 0 2 7 7 2 2 6 8 5 9 7 7 8
Balance Pro M 2 8 7 8 8 6 6 6 0 0 3 5 9 7 3 9 9 6 6 9 9 9 9 8 9 8
Callisto M 1 3 6 3 3 3 0 0 0 0 0 6 9 7 5 7 7 6 6 - 9 9 9 9 9 9
Define S 1 8 8+ 8+ 8+ 8+ 5 4 0 0 6 0 8 0 0 5 5 2 2 4 6 6 8 4 2 8
Epic S/M 2 8 9 9 9 9 6 6 0 0 6 5 9 7 3 9 9 6 6 8+ 9 9 9 8 9 9
Guardsman Max S/P 1 9 8+ 8 8+ 8+ 5 4 0 5 8 8 9 5 8 9 9 7 7 9 9 6 9 9 7+ 9
Hornet A/G 2 0 0 0 0 0 0 0 0 0 0 6 8+ 3 8 8+ 8+ 7+ 7+ 8 9 9 9 8+ 9 5
Lumax/Lexar M/S/P 1 9 9 8 9 9 5 4 0 6 8 8 9 7 8 9 9 8 8 9 9 9 9 9 9 9
Metolachlor2 S 1 8 9 8+ 9 9 5 4 0 0 8+ 0 8 0 0 5 5 2 2 4 6 6 8 4 2 8
s-Metolachlor2 S 1 8 9 8+ 9 9 5 4 0 0 8+ 0 8 0 0 5 5 2 2 4 6 6 8 4 2 8
Metolachlor + atrazine2 S/P 1 9 9 8 9 9 5 4 0 6 8 8 9 6 8 9 9 8 8 9 9 6 9 9 8 9
s-Metolachlor + atrazine2 S/P 1 9 9 8 9 9 5 4 0 6 8 8 9 6 8 9 9 8 8 9 9 6 9 9 8 9
Outlook S 1 8 8+ 8 8+ 8+ 5 4 0 0 8 0 8+ 0 0 5 5 2 2 4 6 6 8 4 2 8
Python A 2 0 0 0 0 0 0 0 0 0 0 5 8 3 7 7 0 5 0 7 9 9 9 8 8+ 5
Simazine P 0 8 7 7 8 8 4 2 0 6 2 7 9 6 7 9 9 7 7 8 9 0 9 8+ 7 5
Lorox/Linex P 2 5 5 5 5 5 0 0 0 0 0 2 7 0 6 8 8 5 5 6 9 9 9 9 6 8
Prowl/Pendimax R 2 8 8 8 8 8 6 6 2 0 0 0 0 0 0 2 2 0 0 2 8 8 9 3 4 8
1Acetochlor, alachlor, and premixes of these with atrazine are available from a number of manufacturers - see corn herbicide descriptions for more information.
Grass weed control ratings presented here for acetochlor are for Degree products, which can provide a longer period of grass control compared to other acetochlor
products. Broadleaf weed control ratings assume an atrazine rate of 1.5 lbs ai/A - the atrazine rate in some premix products may be lower.
2Metolachlor and s-metolachlor, and premixes of these with atrazine, are available from a number of manufacturers - see corn herbicide descriptions for more information.
Metolachlor products have undergone limited testing at their labeled rates in OSU and Purdue University research.
Waterhemp
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Table 5. Weed Response to Herbicides in Corn (continued)
Postemergence
1Apply to Clearfield (imidazolinone-resistant or tolerant) corn only.
2Apply to Liberty Link (glufosinate-resistant) corn only.
3Apply to Roundup Ready (glyphosate-tolerant) corn only.
*Large crabgrass only
Mode of action: A= ALS inhibitor; C= ACCase inhibitor; D= cell membrane disruptor; G= growth regulator; P= photosysnthesis
inhibitor; S= shoot meristem inhibitor; R= root meristem inhibitor; L= glutamine synthetase inhibitor; E= EPSP synthase inhibitor;
M= pigment inhibitor
Rhizome Johnsongrass
Quackgrass
Yellow Nutsedge
Black Nightshade
Burcucumber
Cocklebur
Common Ragweed
Shattercane
Seedling Johnsongrass
Giant Ragweed
Annual Morningglory
Yellow Foxtail
Giant Foxtail
Fall Panicum
Crabgrass
Barnyardgrass
Crop Tolerance
Mode of Action
Jimsonweed
Pigweed (redroot)
Velvetleaf
Smartweed
Triazine-Resistant Lambsquarters
Lambsquarters
ALS-resistant common ragweed
ALS-resistant giant ragweed
Grasses Broadleaf Weeds
Canada Thistle
2,4-D G 2 0 0 0 0 0 0 0 0 0 0 9 7 3 9 9 9 9 9 7 9 9 9 6 8 8 6
Accent A 1 8+ 4 8+ 9 9 9 9 9 9 6 8 0 8 5 0 0 0 0 8 5 5 9 8 5 7 6
Aim D 2 0 0 0 0 0 0 0 0 0 0 8 8 3 3 6 6 3 3 3 7 7 8+ 5 9 7 2
Atrazine P 1 7 5 5 8 8 2 0 0 7 7 9 9 8 9 9 9 8 8 9 9 0 9 9 8 9 6
Basagran P 0 3 0 0 0 0 0 0 0 0 8 4 3 2 9 7 7 6 6 9 6 6 4 9 8+ 4 7
Basis A 2 7 6 7 7 7 7 7 4 - - 6 0 - 7 6 0 0 0 4 8 8 9 8 9 5 5
Basis Gold A/P 2 8+ 4 8 9 8 9 9 6 7 6 8+ 7 8 7 9 8 7 7 8 9 5 9 9 7 8 7
Beacon A 2 2 4 8 7 7 9 9 7 8+ 6 6 8 9 9 9 0 9 0 9 5 5 9 8 8 5 6
Bromoxynil P 1 0 0 0 0 0 0 0 0 0 0 8 9 7 9 9 9 8 8 9 9 9 7 8 8 6 6
Bromoxynil+Atrazine P/P 1 2 2 0 2 2 0 0 0 0 2 9 9 9 9 9 9 9 9 9 9 9 9 9 9 8 7+
Callisto M 1 0 7* 0 0 0 0 0 0 0 5 7 9 - 7 8 8 9 9 - 9 9 8 9 9 9 5
Celebrity Plus A/G 2 8+ 4 8+ 9 9 9 9 9 9 7 9 8 8+ 9 9 9 9 9 9 9 9 9 9 8 8 9
Dicamba G 2 0 0 0 0 0 0 0 0 0 0 9 8 7 9 9 9 9 9 9 9 9 9 8 7+ 8 7
Dicamba+atrazine P/G 2 2 2 0 2 2 0 0 0 0 2 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 7+
Distinct G 2 6 6 6 6 6 0 0 0 0 0 9 8 7 9 9 9 9 9 9 9 9 9 8+ 8 8 9
Equip A 2 8+ 7 7+ 9 7 9 9 8+ 8 3 8 9 8 9 9 0 8 0 8+ 8 8 9 7 9 5 6
Exceed A 1 0 0 7 5 5 9 9 5 5 5 7+ 8 9 9 9 0 9 0 9 8 8 9 9 9 5 6
Glyphosate3 E 0 8 8 8 9 9 9 9 9 9 7 6 8 8 9 8+ 8+ 8+ 8+ 9 8+ 8+ 9 8 8 9 9
Hornet A/G 1 0 0 0 0 0 0 0 0 0 0 7 7 6 9 9 9 9 9 7 7+ 7+ 7+ 9 8+ 5 8+
Laddok P/P 1 2 2 0 2 2 0 0 0 0 8+ 8 8 6 9 9 9 9 9 9 9 5 9 9 9 8 7+
Liberty2 L 0 7 8 8 9 7 8 8 7 6 5 8 9 8 9 9 9 9 9 9 8 8 8 9 8 8 6
Liberty ATZ2 P/L 0 7 7 7 9 7 7 7 7 7 6 9 9 8 9 9 9 9 9 9 9 8 9 9 9 9 7+
Lightning1 A/A 1 7 7 7 8 8 8+ 8+ 7 3 5 7+ 9 6 9 7 0 8 0 8+ 8+ 8+ 9 9 9 5 6
NorthStar A/G 2 2 4 7 6 6 9 9 6 7 5 8 9 9 9 9 7 9 6 9 9 9 9 9 8+ 8 7
Option A 1 8+ 7 8 9 7 9 9 8+ 8+ 3 5 9 8 7 7 0 5 0 8 7 7 8 6 8 5 5
Permit A 1 0 0 0 0 0 0 0 0 0 9 6 4 5 9 8 0 8 0 8 5 5 9 7 8 5 6
Priority A/D 2 0 0 0 0 0 0 0 0 0 9 8 8 5 9 8 6 8 3 8 7 7 9 8 9 6 6
Resource D 2 0 0 0 0 0 0 0 0 0 0 4 4 4 7 7 7 4 4 7 7 7 9 4 9 7 3
Shotgun P/G 2 5 3 3 6 6 0 0 0 4 5 9 9 7 9 9 9 9 9 9 9 9 9 9 8+ 9 3
Spirit A 2 2 2 7 6 6 9 9 6 7 5 7 8 9 9 9 0 9 0 9 6 6 9 8+ 8+ 5 6
Starane G 1 0 0 0 0 0 0 0 0 0 0 9 7 7 8 9 9 0 0 7 0 0 0 7 8 0 0
Steadfast A 2 8 4 8 9 9 9 9 8 8 5 6 0 7 6 4 0 3 0 6 4 4 9 7 5 5 6
Steadfast ATZ A/P 2 8 7 8 9 9 9 9 8 8 7 8+ 7 8 9 9 8 8 7 9 9 4 9 9 8 8 6
Stinger G 0 0 0 0 0 0 0 0 0 0 0 0 8 2 9 9 9 9 9 8 0 0 0 5 0 0 9
WideMatch G 1 0 0 0 0 0 0 0 0 0 0 9 7 7 9 9 9 9 9 8 0 0 0 7 8 0 8
Yukon A/G 2 0 0 0 0 0 0 0 0 0 9 8 7 7 9 9 7 9 7 9 8 8 9 9 9 8 7
Waterhemp
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Corn: Soil-Applied Herbicides — Preplant or Preemergence
Herbicide Formulation Product Rate Range
AAtrex/atrazine 4L 2 - 4 pt
90DF 1.1 - 2.2 lb
Tank-mix with: Most preplant and preemergence corn herbicides.
? Mode of action: photosynthesis inhibitor.
? Atrazine is generally applied at a rate of 1.4 to 2 pounds active ingredient per acre to control broadleaf weeds.
? Low rates may result in reduced control of velvetleaf, cocklebur, giant ragweed, and morningglory. Rates approaching 2
pounds active ingredient may be necessary for velvetleaf control. Atrazine will not control fall panicum, regardless of rate.
? Maximum soil-applied rate on soils not highly erodible is 2 pounds of active ingredient per acre. Maximum rate on highly
erodible soils is 2 pounds active ingredient on fields with at least 30% crop residue, and 1.6 pounds active ingredient on fields
with less than 30% crop residue. Soil applications may be followed with a postemergence application of atrazine, but total of
all treatments cannot exceed 2.5 pounds active ingredient per acre per year.
? Preplant application of atrazine with crop oil concentrate and/or nitrogen fertilizer solution can control small, emerged annual
weeds.
? Plant only corn or sorghum the year (including fall) of atrazine application.
? Where oats, forage legumes, or forage grasses will be planted the following spring, do not apply more than 0.8 pounds active
ingredient per acre.
Herbicide Formulation
Acetochlor various
Tank-mix with: most preemergence corn broadleaf
herbicides - see labels.
? Acetochlor (plus safener) is sold under
variousa trade names, including Harness,
TopNotch, Surpass, Degree, Confidence, and
Volley.
? Acetochlor controls annual grasses, pigweed,
and black nightshade, and control or
suppresses yellow nutsedge, lambsquarters, and
common ragweed. Control of lambsquarters and
common ragweed will generally be less effective
compared to most broadleaf herbicides, but more
effective than other acetamide herbicides.
? Mode of action: shoot meristem inhibitor.
? Can be applied to field corn, popcorn, and production
seed corn, but should generally not be used on
corn seed stock. See labels for precautions.
? Degree and TopNotch are encapsulated products
that can provide a longer period of annual grass
control compared to other acetochlor products.
? Acetochlor products can be applied after planting
but prior to weed emergence, and before corn
height exceeds 11 inches. All acetochlor products
except Degree must be applied using water as the
spray carrier after the corn has emerged.
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? Degree or Degree plus atrazine can be applied to
emerged corn in water or nitrogen fertilizer solution,
but corn should not exceed 6 inches in height if
fertilizer solution is used as the carrier. Do not apply
in fertilizer solution when air temperatures exceed 85
degrees. Mixtures with products other than atrazine
should be applied only in water if the corn has
emerged. Leaf burn may occur when acetochlor is
applied to emerged corn.
Herbicide Formulation
Acetochlor + atrazine Various
Tank-mix with: Most other preemergence broadleaf corn herbicides - see
labels.
? Acetochlor plus atrazine (plus safener) is sold under
various trade names, including Harness Xtra, Degree
Xtra, Fultime, Keystone, Confidence Xtra, and Volley
ATZ. These premix products control annual broadleaf
and grass weeds in corn. The ratio of atrazine
to acetochlor varies with product, and some products
require the addition of atrazine or another broadleaf
herbicide for effective control of some broadleaf
weeds.
? Degree Xtra and Fultime are encapsulated
formulations that can provide a longer
period of annual grass control compared to
other acetochlor products.
? Mode of action: photosynthesis inhibitor
(atrazine), shoot meristem inhibitor (acetochlor).
? Can be applied to field corn, popcorn, and
production seed corn, but should generally
not be used on corn seed stock. See labels
for precautions.
? Can be applied after planting and before
corn height exceeds 11 inches and before
weeds reach the 2-leaf stage. When tankmixing
with postemergence herbicides to control larger weeds, follow the most restrictive label with regard to maximum corn
size.
Corn: Soil-Applied Herbicides — Preplant or Preemergence
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Corn: Soil-Applied Herbicides — Preplant or Preemergence
? All acetochlor products except Degree Xtra should be applied
using water as the spray carrier after the corn has emerged.
? Degree Xtra can be applied in water or nitrogen fertilizer solution,
but corn should not exceed 6 inches in height if fertilizer
solution is used as the carrier. Do not apply in fertilizer solution
when air temperatures exceed 85 degrees. Mixtures with
products other than atrazine should be applied only in water if
the corn has emerged. Leaf burn may occur when applied to
emerged corn.
? Can be mixed with Balance to improve control of velvetleaf,
annual grasses, triazine-resistant lambsquarters,
and burcucumber. See Balance
description for precautions to avoid crop
injury.
Herbicide Formulation
Alachlor Various
Tank-mix with: Atrazine, simazine, Hornet, dicamba,
Marksman, pendimethalin, Lorox, Sencor,
Balance Pro.
? Alachlor controls annual grasses and pigweed, and
controls or suppresses yellow nutsedge and black nightshade.
Product trade names include Lasso and Micro-
Tech among others.
? Mode of action: shoot meristem inhibitor.
? Micro-Tech can be applied after corn emergence until the corn is 5 inches tall, but should be applied before weeds have passed
the 2-leaf stage in a mixture with atrazine. Can be applied to emerged corn in water or nitrogen fertilizer solution. Do not apply
in apply in fertilizer solution when air temperature exceeds 85 degrees. Other alachlor products and combinations should
be applied in water after the corn has emerged. Leaf burn may occur when applied to emerged corn.
? Incorporation to 2 inches will improve yellow nutsedge control and reduce dependence upon rainfall.
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Herbicide Formulation
Alachlor + atrazine various
? Alachlor + atrazine is available from various manufacturers,
and includes products such as Lariat and Bullet . Bullet is a
microencapsulated formulation, which may provide more effective
control than Lariat and other non-encapsulated products
in no-till situations.
? Mode of action: photosynthesis inhibitor (atrazine), shoot
meristem inhibitor (alachlor).
? Lariat can be applied in water, and Bullet can be applied in
water or 28% liquid nitrogen fertilizer, after planting until
weeds reach the 2-leaf stage and when corn is no more than
5 inches tall. Application of Bullet in 28% should not be
made if temperature exceeds 85 F. Leaf burn may occur
when applied to emerged corn.
Herbicide Formulation
Axiom 68DF
Tank-mix with: Atrazine, dicamba, Hornet, pendimethalin,
dicamba+atrazine, Sencor, Balance
Pro, Python, Define.
? Axiom is a premix of flufenacet (Define) plus
metribuzin (Sencor) for control of annual grasses,
lambsquarters, and pigweed. Axiom controls
or suppresses waterhemp, black nightshade, and
yellow nutsedge. Axiom is more effective than
other grass herbicides (Dual, Harness etc) for
early-season suppression of common ragweed
and smartweed.
? Mode of action: shoot meristem inhibitor
(flufenacet), photosynthesis inhibitor (metribuzin).
? Do not apply after corn has emerged.
? Incorporation to a depth of 2 inches will
improve yellow nutsedge control and reduce
dependence upon rainfall.
Corn: Soil-Applied Herbicides — Preplant or Preemergence
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Herbicide Formulation
Balance Pro 4L
Tank-mix with: Most preplant and
preemergence corn herbicides.
? Balance Pro (isoxaflutole) can be
applied preplant or preemergence
for control of annual broadleaf
weeds, including velvetleaf,
pigweed, waterhemp, burcucumber,
black nightshade, smartweed,
lambsquarters (including triazineresistant),
and common ragweed.
Balance is not effective for control
of cocklebur, giant ragweed,
and morningglory, but may help
control these weeds in a tank-mix
with atrazine.
? Mode of action: pigment inhibitor.
? Provides limited early-season control of annual grasses, allowing a reduction in the rate of companion grass herbicides (Dual,
Harness, Surpass, etc).
? Can be applied up to 30 days prior to planting of LibertyLink, Roundup Ready, or Clearfield hybrids where a postemergence
treatment is planned.
? A mix of Balance Pro plus atrazine (1 lb ai/A) will control small, emerged annual weeds (2 inches or less), including field pennycress,
shepherd's-purse, chickweed, henbit, and marestail. Apply with crop oil concentrate or nitrogen fertilizer solution as
the carrier to maximize burndown activity. Tank-mix with 2,4-D, Gramoxone, or glyphosate for improved burndown activity
on larger weeds.
? Isoxaflutole has occasionally injured corn, but severe injury has been fairly rare. Conditions that increase the risk of injury
include high rainfall, cold temperatures, coarse-textured soils, and shallow planting. To reduce the risk of injury, do not exceed
recommended rate for soil type, plant corn at least 1 1/2 inches deep, and make sure seed is completely covered with soil and
the seed furrow is firmed.
? Seed corn inbreds vary in their tolerance; consult seed company before using Balance Pro on seed corn inbreds.
Herbicide Formulation Product Rate Range
Callisto 4L 6 - 7.7 oz
Tank-mix with: Atrazine, most acetamide grass herbicides and acetamide/atrazine premix products.
? Callisto (mesotrione) can be applied preplant or preemergence for control of many annual broadleaf weeds, including lambsquarters
(including triazine-resistant), Pennsylvania smartweed, pigweeds, waterhemp, velvetleaf, and black nightshade. Callisto
has limited activity on giant ragweed, cocklebur, and morningglory, but may help control these weeds in a tank-mix with
atrazine.
? Mode of action: pigment inhibitor.
? Callisto does not control grass weeds, and should be applied in combination with Harness, Dual, TopNotch, or another
acetamide grass herbicide, or an acetamide/atrazine premix (Bicep II, Magnum, Degree Xtra, etc.).
? Can be applied preplant, preemergence, or postemergence to field corn, seed corn, and yellow popcorn. Do not apply to sweet
corn or white popcorn.
? Postemergence rate should not exceed 3 oz/A. To avoid crop injury, do not apply postemergence with emulsifiable concentrate
herbicides or methylated seed oils. To avoid injury to yellow popcorn, apply with crop oil concentrate (do not add fertilizer
solution) after crop emergence.
Corn: Soil-Applied Herbicides —Preplant or Preemergence
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Herbicide Formulation
Define 4SC
Tank-mix with: Atrazine, simazine, Hornet,
Lorox, dicamba, pendimethalin, Sencor,
dicamba+atrazine, Balance Pro.
? Define (flufenacet) can be applied preplant
or preemergence for control of annual grass
weeds, and partial control of black nightshade,
pigweed, and waterhemp.
? Mode of action: shoot meristem inhibitor.
? Can be applied postemergence up to the V5 corn
stage.
Corn: Soil-Applied Herbicides — Preplant or Preemergence
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46
Herbicide Formulatione
Epic 58DF
Tank-mix with: Atrazine, Hornet, Axiom, Define,
dicamba+atrazine, dicamba.
? Epic is a premix of flufenacet (Define) plus
isoxaflutole (Balance) that controls annual
grasses and many annual broadleaf weeds. Epic
is weak on giant ragweed, cocklebur, and annual
morningglories, and should be tank-mixed
with atrazine to improve control of these weeds.
See Balance and Define descriptions for more
information.
? Mode of action: shoot meristem inhibitor (flufenacet),
pigment inhibitor (isoxaflutole).
? Apply to field corn or corn grown for silage only.
? Do not apply after corn has emerged or severe
injury may occur.
? Epic can injure corn under adverse environmental
conditions and on coarse-textured soils. To
avoid injury, do not exceed recommended rate for soil type, plant corn at least 1 1/2 inches deep, and make sure seed furrow is
closed.
Herbicide Formu-
Corn: Soil Applied Herbicides — Preplant or Preemergence
47
lation
Guardsman Max 5L
Tank-mix with: Dicamba, dicamba+atrazine, Outlook,
Atrazine, pendimethalin, simazine,
Accent, Sencor.
? Guardsman Max is a premix of dimethenamid-P (Outlook)
plus atrazine for control of annual grass and
broadleaf weeds in corn.
? Mode of action: phososynthesis inhibitor (atrazine),
shoot mereistem inhibitor (dimethenamid).
? Can be applied early postemergence to corn that is up to
12 inches tall. Weeds should be less than 1 1/2 inches
tall, unless other products are tank-mixed with Guardsman
Max to control larger emerged weeds.
? Can be applied to emerged corn with surfactant or low rates
of liquid nitrogen fertilizer. Do not use liquid fertilizer as the
spray carrier after the crop has emerged. Crop oil concentrate
may be included in postemergence applications only when
Guardsman Max is applied alone or in combination with
atrazine.
Herbicide Formulation
Hornet 78.5WDG
Tank-mix with: Most preplant/preemergence corn herbicides.
? Hornet is a premix of flumetsulam (Python) plus clopyralid
(Stinger). In addition to the broadleaf weeds controlled by
Python, Hornet controls cocklebur and common ragweed.
Expect partial control of giant ragweed.
? Mode of action: ALS inhibitor (flumetsulam), growth regulator (clopyralid).
? Hornet can be tank-mixed at a rate of 3 to 4 oz/A with atrazine premix products (Bicep, Harness Xtra, etc) to improve control of
triazine-resistant lambsquarters and other broadleaf weeds.
? Apply preplant, preemergence, or at the spike stage. When using the rates shown here, apply before the corn is 2 inches tall.
Preplant application with crop oil concentrate can control emerged Canada thistle and small annual broadleaf weeds, including
mustards, shepherd's-purse, ragweeds, and Pennsylvania smartweed.
? Do not apply to sweet corn or popcorn. Inbred lines should be tested for crop tolerance before treating large acreages.
? Hornet can injure corn, especially when growing conditions are unfavorable soon after application. This injury appears as
stunting, temporary yellowing, and reduction in root growth. To avoid injury, plant at least 1 1/2 inches deep and do not use
Hornet in soils with an average of less than 1 1/2 percent organic matter.
? Soil-applied organophosphate insecticides may increase the risk of crop injury, especially when applied in-furrow. To avoid
injury, apply insecticides in a band or T-band. Do not use Hornet if Thimet has been or will be applied to the corn.
? Corn treated with Hornet that is stressed or damaged by herbicide or other factors should not be treated with Accent, Permit,
Exceed, Basis, Beacon, or other ALS-inhibiting herbicides.
? Do not apply where soil pH is greater than 7.8. Do not apply to soils with a combination of pH less than 5.9 and organic matter
content greater than 5%.
Corn: Soil Applied Herbicides — Preplant or Preemergence
48
Herbicide Formulation Product Rate Range
Lumax 4L 2.5 - 3 qts
Lexar 3.7L 3 - 3.5 qts
Tank-mix with: Atrazine, simazine.
? Lumax and Lexar are premixes of atrazine plus s-metolachlor (Dual II Magnum) plus mesotrione (Callisto) for control of grass
and broadleaf weeds in corn. See descriptions for these products for more information.
? Mode of action: photsynthesis inhibitor (atrazine); shoot meristem inhibitor (s-metolachlor); pigment inhibitor (mesotrione).
? Controls most annual broadleaf weeds, but expect partial control of giant ragweed, cocklebur, and annual morningglory.
? Lumax can be applied preplant (up to 14 days before planting), preemergence, or postemergence before field and seed corn exceeds
5 inches in height. Broadleaf weeds should be less than 3 inches tall at the time of postemergence application. Control
of emerged grasses (up to 1.5 inches tall) will require additional atrazine.
? Lexar can be applied preplant, preemergence, or postemergence before field and seed corn exceeds 12 inches in height. Broadleaf
weeds should be less than 5 inches tall at the time of postemergence application. Control of emerged grasses (up to 1.5
inches tall) will require additional atrazine.
? Nonionic surfactant can be used when Lumax is applied to emerged corn. Use of crop oil concentrate may result in temporary
crop injury. Do not apply with methylated seed oil or nitrogen based adjuvants (AMS, UAN, etc) or use fertilizer solution as
the carrier after corn has emerged.
? Do not apply postemergence to corn treated with an organophosphate insecticide at planting. Do not apply in a tank-mix with
an organophosphate or carbamate insecticide or within 7 days before or after an application of these types of insecticides.
Herbicide Formulation
S-metolachlor 7.64E
Metolachlor 7.8E
Tank-mix with: Atrazine, simazine, Hornet, Lorox, dicamba, pendimethalin,
Sencor, dicamba+atrazine, Balance Pro.
? S-metolachlor (Dual II Magnum, Cinch) and metolachlor (Stalwart
C, Parallel) control annual grasses
and pigweed, and control or suppress
waterhemp, black nightshade, and yellow
nutsedge.
? Stalwart and Parallel have undergone
limited testing in OSU and Purdue
University field research. Dual II Magnum includes primarily the S isomer of metolachlor, which allows the use of lower rates
of active ingredient compared to a mix of S and R isomers. The mix of S and R metolachlor isomers in Stalwart and Parallel is
similar to Dual/Dual II, which should result in similar use rates. Stalwart and Parallel use rates are similar to Dual II Magnum,
however, and are lower than use rates of Dual/Dual II. All of the products listed contain a safener to reduce the risk of corn
injury. Dual II Magnum contains benoxacor as the safener and Stalwart contains dichlormid as the safener.
? Mode of action: shoot meristem inhibitor.
? Can be applied preplant or preemergence before the crop and weeds emerge. Can be applied broadcast with atrazine up to
5-inch corn or as a directed spray up to 12-inch corn, and before grass and broadleaf weeds exceed the 2-leaf stage. Do not
apply using fertilizer solution as the spray carrier after the corn has emerged.
? May be applied up to 30 days before planting as a single application.
? Incorporation to a depth of 2 inches will improve yellow nutsedge control and reduce dependence upon rainfall.
Corn: Soil Applied Herbicides — Preplant or Preemergence
????????????????????????????????????
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49
Herbicide Formulation
S-metolachlor + atrazine 5.5L
Metolachlor + atrazine 5.5L
? S-metolachlor plus atrazine (Bicep II
Magnum, Cinch ATZ) and metolachlor
plus atrazine (Stalwart Xtra) control annual
grass and broadleaf weeds in corn.
? Stalwart Xtra has undergone limited
testing in OSU and Purdue University
field research. Bicep II Magnum includes
primarily the S isomer of metolachlor,
which allows the use of lower rates of active
ingredient compared to a mix of S and
R isomers. The mix of S and R metolachlor
isomers in Stalwart Xtra is similar
to Bicep/Bicep II, which should result in
similar use rates. Stalwart Xtra use rates are
similar to Bicep II Magnum, however, and
are lower than use rates of Bicep/Bicep II.
All of the products listed contain a safener
to reduce the risk of corn injury. Bicep II
Magnum contains benoxacor as the safener
and Stalwart Xtra contains dichiormid as
the safener.
? Mode of action: photosynthesis inhibitor
(atrazine), shoot meristem inhibitor (s-metolachlor/metolachlor).
? Can be applied preplant, preemergence, and after corn emergence until corn plants are 5 inches tall and before weeds exceed
the 2-leaf stage. Do not apply using fertilizer solution as the spray carrier after the crop emerges.
? Bicep/Cinch ATZ can be applied postemergence in rescue situations (large weeds) to corn that is 4 to 12 inches tall in combination
with Exceed, Exceed plus Accent, or Spirit.
Herbicide Formulation
Outlook 6EC
Tank-mix with: Atrazine, pendimethalin,
simazine, dicamba,
dicamba+atrazine, Hornet,
Sencor, Balance Pro.
? Outlook (dimethenamid-P) controls annual grasses
and pigweed, and controls or suppresses yellow
nutsedge and black nightshade.
? Mode of action: shoot meristem inhibitor.
? Can be applied after crop emergence, but must be applied before weed emergence, or in a tank mixture with herbicides that control
emerged weeds. Do not apply to corn that is more than 12 inches tall.
? May be applied after corn has emerged with surfactant or low rates of liquid nitrogen fertilizer. Do not use liquid fertilizer as the
spray carrier after the crop has emerged. Crop oil concentrate should not be added after the crop has emerged unless specified
for a particular tank mixture.
Corn: Soil Applied Herbicides — Preplant or Preemergence
50
Herbicide Formulation
Princep/simazine 4L
90DF
Tank-mix with: Atrazine, acetochlor, Dual II
Magnum, Lasso, Bullet, Surpass,
Outlook, Guardsman Max,
MicroTech, Sencor.
? Simazine is often applied at reduced rates in combination with atrazine or atrazine premix products to improve or extend grass
control.
? Mode of action: photosynthesis inhibitor.
? Simazine is more effective than atrazine for control of fall panicum and crabgrass, but is less effective for control of cocklebur,
quackgrass, yellow nutsedge, velvetleaf, and giant ragweed.
? Can be applied at a rate of 1 lb active ingredient/A in the fall prior to corn planting for control of winter annual weeds such as
chickweed, mustards, and deadnettle. Apply with 2,4-D for best results. If weeds are more than an inch or two tall, apply with
Gramoxone or glyphosate.
Herbicide Formulation
Python 80WDG
Tank-mix with: Most other preplant/preemergence corn herbicides.
? Python (flumetsulam) controls annual broadleaf weeds, including triazine-resistant lambsquarters and velvetleaf. Control of
common ragweed and cocklebur is variable, and control of giant ragweed and annual morningglory is usually poor.
? Mode of action: ALS inhibitor.
? Reduced rates of Python can be tank-mixed with atrazine premix products (Bicep, Harness Xtra, etc) to improve control of triazine-
resistant lambsquarters.
? Do not apply to soils with a combination of pH less than 5.9 and organic matter content greater than 5%. Do not apply where
soil pH is greater than 7.8.
? Python can injure corn, especially when growing conditions are unfavorable soon after application. This injury appears as stunting,
temporary yellowing, and reduction in root growth. To avoid injury, plant at least 1 1/2 inches deep and do not use Python
in soils with an average of less than 1 1/2 percent organic matter.
? Soil-applied organophosphate insecticides may increase the risk of crop injury, especially when applied in-furrow. To avoid
injury, apply insecticides in a band or T-band. Do not use Python if Thimet has been or will be applied to the corn.
? Corn treated with Python that is stressed or damaged by herbicide or other factors should not be treated with Accent, Permit,
Exceed, Basis, Beacon, or other ALS-inhibiting herbicides.
? Do not apply to sweet corn or popcorn. Inbred lines should be tested for crop tolerance before treating large acreages.
Corn: Soil Applied Herbicides — Preplant or Preemergence
51
Herbicide Formulation Product Rate Range
Sencor 75DF 2 - 5 1/3 oz
4L 3 - 8 oz
Tank-mix with: Most other corn herbicides.
? Sencor (metribuzin) is labeled for application with other corn herbicides to improve residual control of broadleaf weeds,
including lambsquarters, pigweed, common ragweed, Pennsylvania smartweed, and velvetleaf. In tank-mixes with 2,4-D,
Gramoxone, and/or atrazine, Sencor can also improve burndown of emerged weeds in no-till.
? Mode of action: photosynthesis inhibitor.
? Apply before or after planting, but before corn emergence. Application rates increase when applied more than 10 days before
planting.
? Observe the following precautions to avoid corn injury: Do not apply where soil pH is 7.0 or greater or on coarse-textured
soils with less than 1 1/2% organic matter; do not apply more than 4 ounces/A of Sencor DF on soils with less than 2% organic
matter; plant corn seed at least 1 1/2 inches deep.
? Sencor can be used on field corn and in hybrid seed corn production fields. Both inbred lines should have known tolerance to
Sencor before using in seed production.
Corn: Soil Applied Herbicides — Preplant or Preemergence
52
Corn: Soil-Applied Herbicides —Preemergence Only
Herbicide Formulation Product Rate Range
Lorox 50DF 2/3 - 3 lb
Linex 4L 2/3 - 3 pts
Tank-mix with: Atrazine, Lasso, Bullet, Dual II Magnum, MicroTech, Surpass, Sencor.
? Lorox/Linex (linuron) controls broadleaf weeds. Linuron is generally applied at a rate of 3/4 to 1 lb/A in combination with other
corn herbicides for control of triazine-resistant pigweed and lambsquarters.
? Mode of action: photosynthesis inhibitor.
? Do not use on soils with more than 3 percent organic matter.
? Apply after corn planting, but before emergence.
? To avoid injury, corn should be planted at least 1 3/4 inches deep and adequately covered with soil.
? Do not spray over the top of emerged corn.
Herbicide Formulation
Prowl/Pendimax 3.3EC
Prowl H2O 3.8CS
Tank-mix with: Atrazine, dicamba, Lariat, Bullet,
Dual II Magnum, Lasso,
dicamba+atrazine, Bicep, MicroTech,
acetochlor, Outlook, Guardsman
Max, Sencor.
? Prowl/Pendimax (pendimethalin) controls annual
grasses, pigweed, and lambsquarters (including triazine-
resistant biotypes), and helps control smartweed,
velvetleaf, and seedling johnsongrass. Pendimethalin is
often combined with atrazine for control of grass and
broadleaf weeds where triazine-resistant pigweed and lambsquarters are a problem.
? Mode of action: root meristem inhibitor.
? Can be applied early postemergence on field corn, popcorn, and sweet corn up to the spike stage. See label for details.
? Apply only after planting. Do not incorporate or severe corn injury may result.
? To reduce the risk of corn injury, plant at least 1 1/2 inches deep and ensure good seed to soil contact. Combining pendimethalin
with dicamba may increase the potential for crop injury, especially when corn is under stress from cool, wet conditions.
53
Corn: Postemergence Herbicides — Contact
Herbicide Formulation Product Rate Range
AimEW 1.9L 0.5 oz
Tank-mix with: Most other corn herbicides - see label.
? Aim (carfentrazone-ethyl) is a contact herbicide that controls black nightshade, velvetleaf, redroot pigweed, and small annual
morningglories and lambsquarters. Aim is often tank-mixed with other broadleaf herbicides to improve control of velvetleaf.
? Mode of action: cell membrane disruptor.
? Apply when weeds are 1 to 4 inches tall for best results. Velvetleaf can be controlled up to 36 inches tall. Apply before corn
exceeds the 8-collar stage.
? Apply with nonionic surfactant (0.25% v/v). UAN (2 to 4 gallons/100 gallons) or ammonium sulfate (2 to 4 lbs/A) can be added
if recommended for use with other herbicides in a mix with Aim. In general, Aim should not be tank-mixed with crop oil concentrate
or EC formulations of other herbicides or excessive crop injury may occur. The label does allow use of crop oil concentrate
under dry conditions and in specific tank mixtures. Application with Buctril may cause unacceptable crop injury.
? Aim can be applied with drop nozzles to seed corn production fields. Avoid directing herbicide into the whorl.
? Aim can be applied to sweet corn, but the user assumes all responsibility for herbicide tolerance. Consult seed supplier about
sweet corn tolerance to Aim prior to use.
? Apply in a spray volume of 10 to 20 gpa with a pressure of 20 to 40 psi. Flat fan nozzles are recommended for adequate spray
coverage.
? Add Aim to the spray tank before adding other products.
? Aim usually causes leaf speckling and necrosis. The severity of injury varies with environmental conditions, adjuvants, and
tank-mix partner. To reduce injury, 1) do not apply within 6 to 8 hours of rain, 2) make sure spray nozzles are positioned at least
18 inches above the crop, and 3) avoid direction of excessive amounts of herbicide into corn whorls.
Herbicide Formulation Product Rate Range
AAtrex/atrazine 4L 1 1/2 - 2 qt
90DF 1.67 - 2.22 lb
Tank-mix with: Dicamba, bromoxynil, 2,4-D, Basagran, Accent, Beacon, Sencor, Steadfast.
? Mode of action: photosynthesis inhibitor.
? Maximum rate for postemergence application to fields without soil-applied atrazine in the same year is 2 pounds active ingredient/A.
When applied postemergence to fields with soil-applied atrazine the same year, total amount of atrazine applied may not exceed
2.5 pounds active ingredient.
? Annual broadleaf weeds are more susceptible than annual grasses.
? For grass control, apply when grasses are no more than 1 1/2 inches tall. Rates of 2 pound active ingredient/A are generally
required for grass control. Atrazine will not control fall panicum.
? For control of broadleaf weeds, rates of 1.2 pounds active ingredient may be sufficient. Apply until broadleaf weeds are 4 inches
tall.
? Apply atrazine with 1 quart per acre crop oil concentrate for best results. Mix atrazine with water first, and add oil last.
? Postemergence applications must be made before the crop reaches 12 inches in height.
Herbicide Formulation Product Rate Range
Basagran 4L 1 1/2 - 2 pt
Tank-mix with: Atrazine, Sencor.
? Basagran (bentazon) is a contact herbicide that controls many annual broadleaf weeds, including cocklebur, velvetleaf, and
Pennsylvania smartweed. Basagran controls or suppresses Canada thistle and yellow nutsedge.
? For best results, apply with crop oil concentrate when weeds are in the 2- to 6-leaf stage.
? Apply in combination with atrazine for control of pigweed, lambsquarters, and ragweeds.
54
Herbicide Formulation Product Rate Range
Bromoxynil 2S 1 - 1 1/2 pt
Tank-mix with: Atrazine, 2,4-D, Accent, Beacon, dicamba, Stinger, Sencor, Permit, Exceed, Hornet, Callisto.
? Bromoxynil is sold uner the trade names Buctril, Moxy, and Broclean. Bromxynil is a contact herbicide that controls many annual
broadleaf weeds, including black nightshade, cocklebur, ragweeds, lambsquarters, and smartweed, but is weak on pigweed
and large velvetleaf.
? Mode of action: photosynthesis inhibitor.
? Apply at a rate of 1 pint per acre from corn emergence until tassel emergence. The 1 1/2-pint rate may be applied after corn reaches
the 4-leaf stage and before tassel emergence. Maximum corn size at the time of application varies with the tank-mix partner.
? Do not apply to seed corn inbreds or popcorn prior to the 3-leaf stage.
? Do not use surfactant or crop oil when applying bromxynil alone or with most other herbicides. Nonionic surfactant and fertilizer
solution are allowed in some tank mixtures.
? Apply in a minimum volume of 10 gpa at a minimum pressure of 30 psi using flat fan nozzles.
? May cause corn leaf burn, but effects are usually temporary.
Herbicide Formulation Product Rate Range
Buctril/atrazine 3L 1 1/2 - 3 pt
Moxy/atrazine
Tank-mix with: Accent, dicamba, 2,4-D, Stinger, Beacon, Callisto.
? These products are 1:2 premixes of bromoxynil plus atrazine for control of most broadleaf weeds.
? Mode of action: photosynthesis inhibitor.
? Can be applied at a rate of 1 1/2 to 2 pints per acre after corn emergence and before corn is 12 inches tall. The 3-pint rate may be
applied after corn reaches the 4-leaf stage and before corn is 12 inches tall.
? Do not use surfactant, crop oil, liquid fertilizers, or other additives when applying Buctril/atrazine or Moxy/atrazine alone or with
most other herbicides. Nonionic surfactant and fertilizer solution are allowed in some tank mixtures.
? Apply in a volume of at least 10 gallons per acre at a minimum pressure of 30 psi using flat fan nozzles.
Herbicide Formulation Product Rate Range
Laddok S-12 5L 1 1/3 - 2 1/3 pt
Tank-mix with: 2,4-D LVE, atrazine, Stinger, dicamba, Sencor.
? Laddok/Headline is a 1:1 premix of bentazon (Basagran) plus atrazine for control of most broadleaf weeds, and suppression or
control of yellow nutsedge, Canada thistle, and some perennial vines.
? Mode of action: photosynthesis inhibitor.
? Application rate varies with weed species and size. Apply with UAN (urea ammonium nitrate) solution, ammonium sulfate,
nonphytotoxic oil concentrate, or Dash. The label allows combinations of spray additives, which vary with the weed species
present. UAN or ammonium sulfate should be added when velvetleaf is the target weed, and may also improve control of
cocklebur and Pennsylvania smartweed. Crop oil concentrate should also be added when common lambsquarters or common
ragweed is present. Crop oil concentrate or Dash should be used when Canada thistle, yellow nutsedge, or field bindweed is
present.
? Apply in a spray volume of at least 10 gpa with a minimum pressure of 40 psi. Increasing the spray volume (up to 50 gpa) will
improve control when the crop and weed foliage is dense.
? To suppress Canada thistle, apply 2 1/3 pints when thistle plants are 8 to 10 inches tall until the bud stage.
? A single application of 2 1/3 pints of Laddok can suppress yellow nutsedge that is 1 to 4 inches tall.
? Provides better control of velvetleaf, annual morningglory, lambsquarters, and pigweed than Basagran alone, but is no more
effective on triazine-resistant lambsquarters.
Corn: Postemergence Herbicides — Contact
55
Herbicide Formulation Product Rate Range
Resource 0.86EC 4 to 6 oz (broadcast)
4 to 8 oz (directed)
Tank-mix with: Accent, dicamba, atrazine, 2,4-D, Exceed, dicamba+atrazine.
? Resource (flumiclorac) is a contact herbicide that controls velvetleaf (up to 10 inches tall) and pigweeds. Control of lambsquarters
is variable, and some other broadleaf weeds will be suppressed.
? Mode of action: cell membrane disruptor.
? Apply when corn is in the 2- to 10-leaf stage and broadleaf weeds are in the 2- to 3-leaf stage for best results. Use a directed
spray if corn size prevents adequate spray coverage of weeds.
? Crop oil concentrate should be included when Resource is applied alone. Use 1 pint/A for broadcast application and 1 quart/A
for directed application. Nitrogen fertilizer solution or ammonium sulfate can also be added to improve control of large velvetleaf.
Adjuvant recommendations vary with the tank-mix partner. See the label for more information.
? Apply in a spray volume of at least 10 gpa with a spray pressure of 30 to 60 psi.
? Allow 1 hour between application and rainfall.
Herbicide Formulation Product Rate Range
Sencor 75DF 1.6 - 3 oz
Tank-mix with: Basagran, 2,4-D, dicamba, bromxynil, Buctril/atrazine, Laddok, atrazine, dicamba+atrazine, Resource, Hornet.
? Mode of action: photosynthesis inhibitor.
? Applying Sencor in combination with one of the postemergence herbicides listed above allows a reduction in the rate of the
tank-mix partner and improves control of some annual and perennial broadleaf weeds.
? The 2 ounce rate can be applied broadcast to corn in combination with Basagran (up to 1 pint/A), 2,4-D (up to 1/2 pint/A), dicamba
(up to 1 pint/A), dicamba+atrazine (up to 2 pints/A), Laddok (up to 1 2/3 pints/A) or atrazine (up to 1 1/2 lbs/A). When
applying broadcast with Buctril, use a Sencor rate of 1.6 to 2 ounces/A. Sencor rates greater than 2 ounces/A must be applied
post-directed only in combination with Buctril or up to 3/4 pint of 2,4-D.
? Maximum corn size at the time of application depends upon the tank-mix partner. See label for more information.
? Do not apply with crop oil concentrate. Nitrogen fertilizer solution or ammonium sulfate can be used in tank-mixes with
Basagran. Use of nonionic surfactant is allowed with atrazine and dicamba. Do not use any spray additives when mixing with
Buctril.
? Do not use on popcorn, sweet corn, or corn inbreds grown for seed.
? This treatment can result in temporary yellowing or leaf burn, especially when corn is under stress. Do not apply when corn
and weeds are not actively growing or when corn is under stress.
Corn: Postemergence Herbicides — Contact
56
Herbicide Formulation Product Rate Range
Accent SP 75DF 2/3 oz (1 packet per 4 acres)
Tank-mix with: Bromoxynil, dicamba, dicamba+atrazine, atrazine, Buctril+atrazine, Beacon, Resource, Exceed, Callisto.
? Accent (nicosulfuron) is a translocated sulfonylurea herbicide that controls annual and perennial grasses and some annual
broadleaf weeds, including foxtails, fall panicum, johnsongrass, quackgrass, shattercane, Pennsylvania smartweed, pigweed,
and annual morningglory. Accent does not control crabgrass. Application of Accent with a dicamba product will suppress or
control many perennial broadleaf weeds..
? Mode of action: ALS inhibitor.
? Accent is labeled for use on field corn, popcorn, seed corn, and some sweet corn hybrids grown for processing. Growers
should contact seed suppliers for recommendations and information on crop tolerance and use of soil-applied organophosphate
insecticides prior to Accent use on popcorn or seed corn. Do not apply to any white popcorn inbred or hybrid unless approved
by the seed supplier. Accent can be used on High Lysine, Waxy, White or other Food Grade hybrids. A list of approved sweet
corn hybrids is available from DuPont.
? Accent can be applied broadcast or as a directed spray to field corn that is up to 20 inches tall or up to 6 collars (whichever occurs
first). Apply as a directed spray when corn is 20 to 36 inches tall. Do not apply to corn that is at or past the 10-collar stage
or more than 36 inches tall.
? Accent can be applied broadcast to popcorn or seed corn that is less than 20 inches tall or up to 6 collars (whichever occurs
first). Do not apply to popcorn or seed corn that is more than 20 inches tall.
? OSU research has shown it can be difficult to achieve adequate season-long weed control with a single postemergence application
of herbicides with limited residual activity (such as Accent). Applying a reduced rate of a preplant or preemergence herbicide
prior to postemergence herbicide application will result in more consistent control of longer duration.
? For best results, apply Accent with crop oil concentrate (1 gallon/100 gallons spray) plus nitrogen fertilizer solution (28% - 2
to 4 quarts/A) or ammonium sulfate (2 to 4 lbs/A). Substituting a methylated seed oil (Meth Oil, Priority MSO, Sun-It II, for
example) for crop oil concentrate can improve control under drought-stressed conditions. Nonionic surfactant (1 to 2 qts/100
gallons spray) can also be used instead of crop oil if required in a tank-mix with another herbicide.
? Apply in a spray volume of at least 10 gpa with a pressure of 20 to 40 psi. Increase volume to at least 15 gpa in heavy weed
pressure. Avoid spraying excessive amounts of herbicide directly into the corn whorl.
? Apply when grasses are at the following heights: foxtails and fall panicum — 2 to 4 inches; quackgrass — 4 to 10 inches; shattercane
and seedling johnsongrass — 4 to 12 inches; rhizome johnsongrass — 8 to 18 inches.
? Control of yellow and green foxtail may be reduced in some tank-mixes with broadleaf herbicides. Consult the label for spray
additive recommendations when tank-mixing with broadleaf herbicides, and follow the most restrictive label with regard to
maximum corn size at the time of application.
? Control may be reduced if applied during conditions of drought stress, abnormally hot or cold weather, when daytime temperatures
do not exceed 50 degrees, or following periods of large day/night temperature fluctuations.
? Where Accent is applied to corn previously treated with soil applications of organophosphate insecticides, temporary crop injury
may occur. Do not tank-mix Accent with foliar-applied organophosphate insecticides or with Basagran, Laddok, or 2,4-D.
Do not apply these materials within 7 days before through 3 days after applying Accent.
Herbicide Formulation Product Rate Range
Basis 75DF 1/3 oz (1 packet per 4 acres)
Tank-mix with: Atrazine, dicamba, dicamba+atrazine, pendimethalin.
? Basis is a premix of rimsulfuron plus thifensulfuron (Harmony GT), translocated sulfonylurea herbicides. Basis controls
small annual grasses and a few broadleaf weeds, and provides a few weeks of residual control of foxtails, lambsquarters, and
pigweeds.
? Mode of action: ALS inhibitor.
? Apply when field corn is in the spike to 2-collar (approx. 6 inches) stage and before grass weed height exceeds 2 inches.
Grasses controlled include foxtails, barnyardgrass, and fall panicum. A cultivation is generally required following Basis application
for effective grass control. In OSU research, Basis has provided only fair control of grasses without cultivation.
? Controls smartweeds, lambsquarters, pigweed, and velvetleaf that are 1 to 3 inches tall. Basis should be tank mixed with another
postemergence herbicide if other broadleaf weeds are present.
Corn: Postemergence Herbicides — Systemic
57
? Apply in a minimum spray volume of 15 gpa with a pressure of 20 to 40 psi. Include nonionic surfactant (1 to 2 quarts/100
gallons) plus nitrogen fertilizer solution (28% - 2 to 4 quarts/100 gallons) or ammonium sulfate (2 to 4 lb/100 gallons). Crop
oil concentrate (1 to 2 gallons/100 gallons) can be substituted for surfactant under drought conditions.
? Basis may cause temporary crop injury, including stunting and bleaching of new growth. Risk of injury increases if corn is
treated after the 2-collar stage.
? Do not apply to seed corn, popcorn, or sweet corn.
Herbicide Formulation Product Rate Range
Basis Gold 89.5DF 14 oz (1 packet per 4 acres)
Tank-mix with: Accent, dicamba, Hornet, Distinct, Callisto.
? Basis Gold is a premix of nicosulfuron (Accent), rimsulfuron, and atrazine for control of broadleaf and grass weeds in corn.
See descriptions for the component herbicides for more information.
? Mode of action: ALS inhibitor (nicosulfuron, rimsulfuron), photosynthetic inhibitor (atrazine).
? Controls giant and green foxtail, fall panicum, and barnyardgrass up to 3 inches tall, yellow foxtail up to 2 inches tall, shattercane
up to 6 inches tall, and quackgrass up to 4 inches tall. Does not control crabgrass. Control of larger annual or perennial
grass weeds with Basis Gold is less effective than the labeled rate of Accent.
? Controls most annual broadleaf weeds up to 3 or 4 inches tall, including ragweeds, cocklebur, velvetleaf, lambsquarters (except
triazine-resistant), pigweeds, waterhemp, Pennsylvania smartweed, and annual morningglories. Tank-mixing with a dicamba
product generally improves control of broadleaf weeds, and is nesessary for large annual broadleaf weeds or perennial
broadleaf weeds.
? Can be applied to field corn up to 12 inches tall, or before 6 collars are present, whichever occurs first. Do not apply to seed
corn, popcorn, or sweet corn.
? Apply with crop oil concentrate (1 gallon/100 gallons spray) plus liquid nitrogen fertilizer (1 to 2 quarts/A) or ammonium
sulfate (2 lbs/A). Substituting a methylated seed oil (Meth Oil, Priority MSO, Sun-It II, for example) for crop oil concentrate
may improve control under drought-stressed conditions. Mixtures with some herbicides (Clarity) can be applied using nonionic
surfactant instead of crop oil concentrate, but a reduction in grass control may occur.
? OSU research has shown it can be difficult to achieve adequate season-long weed control with a single postemergence application
of herbicides with limited residual activity (such as Basis Gold). Applying a reduced rate of a preplant or preemergence
herbicide prior to postemergence herbicide application will result in more consistent control of longer duration.
? Apply in a spray volume of at least 15 gpa with a spray pressure of 20 to 40 psi. Increase spray volume and pressure as weed
density and size increase. Flat fan or Turbo Floodjet nozzles are recommended.
? To avoid a reduction in grass control or crop injury, do not tank-mix with 2,4-D, Basagran, Laddok, or organophosphate
insecticides.
? Where Basis Gold is applied to corn previously treated with soil applications of organophosphate insecticides, temporary crop
injury may occur. Application of Basis Gold to corn treated with Thimet may cause severe crop injury.
Herbicide Formulation Product Rate Range
Beacon 75DF 3/8 - 3/4 oz
Tank-mix with: Bromoxynil, 2,4-D, dicamba, Accent, Atrazine, Marksman, Buctril+atrazine, Resource.
? Beacon (primisulfuron) is a translocated sulfonylurea herbicide that controls or suppresses annual and perennial grasses and
controls annual broadleaf weeds. Beacon provides only partial control of foxtail species and may be less effective than Accent
for rhizome johnsongrass and quackgrass control, but is generally more effective than Accent for broadleaf weed control.
Does not control ALS-resistant weeds.
? Mode of action: ALS inhibitor.
? Mixtures of Beacon plus dicamba or 2,4-D will suppress a number of perennial broadleaf weeds.
? Beacon is labeled for use on field corn, popcorn, and seed corn. Popcorn and inbred lines grown for seed may be severely
injured by Beacon and should be thoroughly tested for potential sensitivity to Beacon before treating large acreage. Do not
use Beacon on sweet corn.
? Apply broadcast or as a directed spray when field corn is between 4 and 20 inches tall, and as a directed spray after corn is 20
inches tall and before tassel emergence. All applications to inbred lines and popcorn should be made post-directed or semidirected
(nozzles positioned to avoid placing spray in whorl) after corn is 10 inches tall but before tassel emergence.
Corn: Postemergence Herbicides — Systemic
58
? Apply with nonionic surfactant (0.25% v/v) or crop oil concentrate (1 to 4 pints per acre); crop oil concentrate is generally the
preferred additive. Liquid nitrogen fertilizer (2 to 4 quarts/A) or ammonium sulfate (2 to 4 lbs/A) may be added, but should
not substitute for surfactant or oil concentrate. Crop oil concentrate plus nitrogen fertilizer can be use when tank-mixing with
atrazine, Accent, or 2 oz/A or less of dicamba. Most other tank-mixes should be applied with nonionic surfactant. See label
for detailed information on tank-mixing.
? Apply when grasses are at the following heights: shattercane and seedling johnsongrass — 4 to 12 inches; rhizome johnsongrass
— 8 to 16 inches; quackgrass — 4 to 8 inches; fall panicum — less than 2 inches. Beacon will control common and
giant ragweed that are 2 to 9 inches tall. Most other broadleaf weeds should be 1 to 4 inches tall when Beacon is applied.
? Do not make a foliar postemergence or a soil application of any organophosphate insecticide within 10 days before or 7 days after
Beacon application.
Herbicide Formulation Product Rate Range
Callisto 4L 3 oz
Tank-mix with: Atrazine, Liberty, Liberty ATZ, Basagran, Accent, Accent Gold, Basis Gold, Steadfast, bromoxynil.
? Callisto (mesotrione) is a systemic herbicide that controls annual broadleaf weeds, including cocklebur, atriplex, lambsquarters
(including triazine-resistant), giant ragweed, Pennsylvania smartweed, pigweeds, waterhemp, velvetleaf, and black nightshade.
Callisto alone does not provide consistent control of common ragweed or morningglory. The addition of atrazine (1/2
pint) improves control of a number of weeds, and is required for consistent control of common ragweed and morningglory.
Where corn is more than 12 inches tall and atrazine cannot be used, a mixture of Callisto plus Buctril can improve control of
ragweeds.
? Mode of action: pigment inhibitor.
? Apply when weeds are less than 5 inches tall for best results. Apply with atrazine (1/2 pint) if weeds are more than 5 inches
tall.
? Callisto can be applied to field corn, seed corn, and yellow (not white) popcorn up to 30 inches tall or the 8-leaf stage. Callisto
plus atrazine can be applied to corn up to 12 inches tall.
? Apply with crop oil concentrate (1% v/v) plus UAN (2.5% v/v) or AMS (8.5 lb/100 gallons). Do not use methylated seed oil
(MSO) or MSO blend adjuvants. To avoid injury to yellow popcorn, apply with crop oil concentrate alone (do not add fertilizer
solution) after crop emergence.
? Apply in a spray volume of 10 to 30 gpa, but use a volume of at least 20 gpa if weed foliage is dense.
? To avoid severe crop injury, do not apply Callisto postemergence if the corn was previously treated with Lorsban. Do not
tank-mix Callisto with organophosphate or carbamate insecticides. Do not make a foliar application of any organophosphate
or carbamate insecticide within 7 days before or after a postemergence Callisto application. Callisto can be applied postemergence
in a tank-mix with pyrethroid insecticides.
? To avoid crop injury, do not apply Callisto postemergence in a tank-mix with emulsifiable concentrate grass herbicides (Dual II
Magnum, etc).
Herbicide Formulation Product Rate Range
Celebrity Plus 75.3DF 4.7 oz
Tank-mix with: Accent, atrazine, Distinct.
? Celebrity Plus is a premix of nicosulfuron (Accent) plus Distinct (dicamba plus diflufenzopyr) that controls annual grass and
broadleaf weeds in corn.
? Mode of action: acetolactate synthase inhibitor (nicosulfuron), growth regulator (dicamba), auxin transport inhibitor (diflufenzopyr).
? Apply with nonionic surfactant (1 to 2 qts/100 gallons) and 28% UAN (1 to 2 qta/A) or ammonium sulfate (1 to 2 lbs/A).
? Can be applied broadcast or as a directed spray to field corn that is up to 24 inches tall or up to 6 collars (whichever comes
first). As with any dicamba product, risk of corn injury increases when corn exceeds 8 to 10 inches in height. To reduce risk
of injury, make sure nozzle spacing and spray boom height are set to minimize interception of spray by the corn plants.
Corn: Postemergence Herbicides — Systemic
59
? Where Celebrity Plus is applied to corn previously treated with soil applications of organophosphate insecticides, temporary
crop injury may occur.
? Most of the guidelines and restrictions on Accent and Distinct labels also apply to this product.
Herbicide Formulation Product Rate Range
Dicamba 4L 1/2 - 1 pt
Tank-mix with: Most other postemergence corn herbicides - see labels.
? Dicamba is sold under a number of trade names, including Banvel, Clarity, Sterling, and Oracle. Dicamba is a translocated herbicide
that controls many annual broadleaf weeds, including pigweeds, ragweeds, black nightshade, cocklebur, and Pennsylvania
smartweed. Control of velvetleaf can be variable. Dicamba will control or suppress perennial broadleaf weeds, especially when
applied with ALS inhibitor herbicides.
? Mode of action: growth regulator.
? Apply 1/2 to 1 pint when corn is in the spike to five-leaf stage, or until corn is 8 inches tall, whichever occurs first. Do not apply
more than 1/2 pint on coarse-textured soils. If the 6th true leaf is emerging from the whorl, or corn is more than 8 inches tall, a
rate of 1/2 pint can be applied until corn is 36 inches tall, or until 15 days before tassel emergence. Apply as a directed spray
when corn leaves prevent proper spray coverage, or sensitive crops are growing nearby.
? The 1 pint rate provides limited residual broadleaf weed control.
? Apply with 1/2 to 1 gallon per acre of liquid nitrogen fertilizer solution (28%) when velvetleaf is a target weed. Can be applied
with surfactant or crop oil to improve control in dry growing conditions. Do not apply with crop oil when corn exceeds 5 inches
in height.
? With any dicamba product, risk of corn injury increases when corn exceeds 8 to 10 inches in height. To reduce risk of injury,
make sure nozzle spacing and spray boom height are set to minimize interception of spray by the corn plants.
? Soybeans and vegetables are extremely susceptible to dicamba drift and vapors. Apply in a spray volume of 20 gpa at a pressure
of less than 20 psi to reduce drift. Do not apply where sensitive crops are growing nearby if winds over 5 MPH are moving in
the direction of sensitive crops, corn is more than 24 inches tall, soybeans are more than 10 inches tall, or soybeans have begun
to bloom. Do not apply Sterling/Banvel/Oracle when air temperatures on the day of application will exceed 85 degrees.
Herbicide Formulation Product Rate Range
Dicamba + atrazine 3.2L 3 1/2 pt
Tank-mix with: See labels.
? Dicamba plus atrazine is sold under a number of trade names, including Marksman, Sterling Plus, Banvel-K+atrazine, and Stratos.
These products control most annual broadleaf weeds, and suppress or control perennial broadleaf weeds.
? Mode of action: photosynthesis inhibitor (atrazine), growth regulator (dicamba).
? Apply when corn is in the spike to five-leaf stage, or until corn is 8 inches tall, whichever comes first. The rate is 3 1/2 pints on
medium- or fine-textured soils with at least 2 percent organic matter, and 2 pints on coarse-textured soils. Provides some residual
broadleaf weed control.
? The addition of crop oil, surfactant, or liquid nitrogen fertilizer may improve control, especially when weeds are drought-stressed.
Apply with nitrogen fertilizer solution if velvetleaf is a target weed. Application with crop oils may cause crop injury. Do not
apply with crop oil after corn exceeds 5 inches in height.
? Precautions on spray drift, volatility, and corn injury are the same as for dicamba. See dicamba description for more information.
Corn: Postemergence Herbicides — Systemic
60
Herbicide Formulation Product Rate Range
Distinct 76.4DF 4 - 6 oz
Tank-mix with: See label.
? Distinct is a premix of dicamba (Clarity) plus diflufenzopyr for control of most annual broadleaf weeds in corn. Distinct can
be weak on velvetleaf, although it is more effective than dicamba alone.
? Mode of action: growth regulator (dicamba), auxin transport inhibitor (diflufenzopyr).
? Distinct can control or suppress small annual grasses that have escaped premergence herbicide treatments. Effectiveness on
grasses is variable, and can be reduced under dry conditions.
? Distinct is generally more effective than other dicamba products on perennial broadleaf weeds, and has provided excellent
control of Canada thistle and hedge bindweed in OSU research.
? Apply 6 oz/A when corn is 4 to 10 inches tall, and 4 oz/A when corn is 10 to 24 inches tall. As with any dicamba product, risk
of corn injury increases when corn exceeds 8 to 10 inches in height. To reduce risk of injury, make sure nozzle spacing and
spray boom height are set to minimize interception of spray by the corn plants.
? Apply with nonionic surfactant (0.25% v/v) plus UAN solution (1.25% v/v) or ammonium sulfate (5 lbs/100 gallons). To
avoid mixing problems, add Distinct to spray tank before adding ammonium sulfate.
? Volatility of Distinct is similar to Clarity. Take precautions to avoid contact of Distinct with sensitive plants via drift or
volatility. Exposure of soybeans to Distinct via sprayer contamination or spray particle drift will result in more severe injury
compared to other dicamba products.
Herbicide Formulation Product Rate Range
Equip 32WDG 1.5 oz
Tank-mix with: See label.
? Equip is a premix of foramsulfuron (Option) plus iodosulfuron plus a safener for control of annual grass and broadleaf weeds.
? Mode of action: ALS inhibitor.
? Apply broadcast up the V5 corn stage. Can be applied as a directed spray using drop nozzles when corn is up to 36 inches tall
or up to the V8 stage. Do not apply to seed corn, popcorn, or sweet corn.
? Apply when broadleaf weeds are 3 to 4 inches tall and grass weeds are at the following heights: foxtails, fall panicum - up
to 3 inches; barnyardgrass - up to 4 inches; quackgrass, wirestem muhly - up to 6 inches; johnsongrass, shattercane - up to 8
inches.
? Apply in a spray volume of 10 to 20 gpa with a methylated seed oil (1.5 pts/A) plus 28% UAN (1.5 to 2 qts/A) or ammonium
sulfate (1.5 to 3 lbs/A). For spray volumes of 15 gpa or greater, the methylated seed oil rate can be 1% v/v.
? Do not use Equip in the same season as Thimet. Application of Equip following an at-planting Lorsban application may result
in temporary crop injury. Foliar applications of an organophosphate insecticide should not occur within 7 days of Equip application.
Herbicide Formulation Product Rate Range
Exceed 57DF 1 oz (1 packet per 4 acres)
Tank-mix with: Dicamba, 2,4-D, atrazine, bromoxynil, Buctril+atrazine, dicamba+atrazine, Beacon, Accent, Steadfast,
Steadfast ATZ.
? Exceed is a premix of prosulfuron (Peak) plus primisulfuron (Beacon), translocated sulfonylurea herbicides. Exceed controls
annual broadleaf weeds, including velvetleaf, ragweeds, cocklebur, Pennsylvania smartweed, burcucumber, and redroot pigweed.
Exceed can suppress or control small (<2 inch) annual grasses in corn, and can control or suppress perennial broadleaf
weeds. Most effective control/suppression of perennials will occur when tank-mixed with 2,4-D or a dicamba product. Exceed
is weak on black nightshade, annual morningglories, and yellow nutsedge. Does not control ALS-resistant weeds.
? Mode of action: ALS inhibitor.
Corn: Postemergence Herbicides — Systemic
61
Corn: Postemergence Herbicides — Systemic
? Exceed can occasionally carryover and injure soybeans grown the following year. Conditions increasing the risk of carryover
include high soil pH, low rainfall and soil moisture for several months following application, and late-season application. Follow
these guidelines to avoid carryover: 1) avoid use where soil pH is greater than 7.8. If used where soil pH is greater than
7.8, less than one inch of rain occurs within one month of application, or less than 12 inches of rain occurs within 5 months
after application, plant only corn or small grains the following year; 2) north of Interstate 70, do not plant soybeans within 18
months of application (STS soybeans can be planted 10 months after application); 3) south of I-70, soybeans can be planted 10
months after application where soil pH is less than 7.8; and 4) do not apply after June 30. See label for guidelines on rotation
to other crops.
? Control of lambsquarters can be variable, especially when tall or drought-stressed. Tank-mix with 2 to 4 ounces per acre of
dicamba for more consistent control of lambsquarters. Crop oil concentrate can be used when the Banvel/Clarity rate is 2 oz/A
or less; use nonionic surfactant with higher rates.
? Apply when annual broadleaf weeds are 1 to 5 inches tall for best results. Exceed will control seedling johnsongrass and shattercane
that are 4 to 12 inches tall.
? Apply broadcast or directed when field corn is 4 to 30 inches tall. To avoid injury and improve spray coverage on weeds, apply
as a directed spray using drop nozzles when corn is more than 20 inches tall.
? For popcorn, apply as a directed spray using drop nozzles when corn plants are 10 to 30 inches tall, and before tassel emergence.
For seed corn inbreds, Exceed can be applied broadcast when corn is between 4 and 20 inches tall, or until the 6-collar
stage, whicever occurs first. Use drop nozzles when seed corn inbreds are 20 to 30 inches tall and before tassel emergence.
Inbred lines and popcorn hybrids should be thoroughly tested for sensitivity to Exceed before treating large acreages. Do not
apply to sweet corn.
? Apply in a minimum spray volume of 10 gpa. Increasing the volume to 20 gpa can improve control in dense weed infestations.
? Apply with crop oil concentrate (1 to 4 pints/A) or nonionic surfactant (1 to 2 quarts/100 gallons). Nitrogen fertilizer solution
(2 to 4 quarts/A) or AMS (2 lbs/A) may be added to improve control of velvetleaf and other weeds. Crop oil concentrate
is generally more effective than nonionic surfactant. Use of a methylated seed oil (Meth Oil, Priority MSO, Sun-It II, for
example) may improve control when weeds are large or drought-stressed.
? Do not make a foliar postemergence or a soil application of any organophosphate insecticide within 10 days before or 7 days
after Exceed application.
Herbicide Formulation Product Rate Range
Hornet 78.5WDG 2 to 5 oz
Tank-mix with: Dicamba, 2,4-D, atrazine, bromoxynil, Basis Gold, Accent, Aim, Stinger, Steadfast, Option, Callisto, Steadfast,
Steadfast ATZ.
? Hornet is a premix of flumetsulam (Python) plus clopyralid (Stinger), translocated herbicides, that controls annual broadleaf
weeds and suppresses perennial broadleaf weeds. Hornet controls ragweeds, velvetleaf, cocklebur, Pennsylvania smartweed,
and small marestail, but is not effective for control of lambsquarters, pigweeds, black nightshade, and annual morningglory.
The higher rates can suppress or control some perennial weeds, including dandelion and Jerusalem artichoke.
? Mode of action: ALS inhibitor (flumetsulam), growth regulator (clopyralid).
? Hornet will control the above-ground growth of Canada thistle, but may be less effective than labeled rates of Stinger for longterm
control of thistle. Tank-mixing Hornet with Stinger will improve long-term control. Apply before thistle plants are in the
bud stage for best results.
? Apply broadcast when weeds are 2 to 8 inches tall and field corn is up to 20 inches tall or at the 6-collar stage, whichever occurs
first. Hornet can be applied as a directed postemergence application using drop nozzles to corn that is 20 to 36 inches tall.
? Apply with nonionic surfactant (1 quart/100 gallons) or crop oil concentrate (1 gallon/100 gallons). Under dry conditions, the
addition of nitrogen fertilizer solution (2 1/2 gallons/100 gallons) may improve control.
? Apply in a spray volume of 10 to 40 gpa with a spray pressure of 20 to 40 psi.
? To avoid severe crop injury, do not apply to corn previously treated with Thimet. Application to corn treated with other organophosphate
insecticides may cause temporary crop injury. Do not tank-mix with foliar organophosphate insecticides, or apply
insecticides within 10 days before or after Hornet application.
? Do not apply to corn that shows symptoms of injury from previously applied herbicides.
? Do not apply to popcorn or sweet corn. Corn inbred lines may be injured by Hornet.
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Corn: Postemergence Herbicides — Systemic
Herbicide Formulation Product Rate Range
NorthStar 47DF 5 oz
Tank-mix with: Atrazine, Accent, Resource, dicamba, dicamba+atrazine.
? NorthStar is a premix of primisulfuron (Beacon) plus dicamba (Banvel) for control of most annual broadleaf weeds and suppression
or control of annual and perennial grasses. NorthStar will suppress a number of perennial broadleaf weeds. See
Beacon and dicamba descriptions for more information and precautions on use.
? Mode of action: ALS inhibitor (primisulfuron), growth regulator (dicamba).
? Can be applied broadcast or directed to field corn that is between 4 and 20 inches tall. Apply using drop nozzles when corn is
20 inches (V6) up to 36 inches tall or 15 days before tassel emergence, whichever occurs first.
? For popcorn and seed corn inbreds, apply as a directed spray using drop nozzles when corn is between 10 and 36 inches tall
or 15 days before tassel emergence, whichever occurs first. Inbred lines and popcorn hybrids should be thoroughly tested for
sensitivity to NorthStar before treating large acreages.
? Apply with nonionic surfactant (0.25% v/v) or crop oil concentrate (1 to 4 pints/A), but do not use crop oil concentrate if corn
is more than 12 inches tall. Nitrogen fertilizer solution (2 to 4 qts/A) or ammonium sulfate (2 to 4 lbs/A) may also be added.
Herbicide Formulation Product Rate Range
Option 35WDG 1 1/2 to 1 3/4 oz
Tank-mix with: Atrazine, Beacon, dicamba, Distinct, Hornet, dicamba+atrazine, NorthStar, Spirit, Exceed, Callisto.
? Option (foramsulfuron + safener) is a translocated sulfonylurea herbicide that controls annual grasses and a few small annual
broadleaf weeds. Option should generally be mixed with another herbicide that has activity on broadleaf weeds unless grass
weeds are the sole target.
? Mode of action: ALS inhibitor.
? Apply broadcast until field corn is in the V6 stage. Can be applied as a directed spray using drop nozzles when corn is 16 to 36
inches tall. Do not apply to sweet corn, popcorn, or seed corn.
? Apply when grass weeds are at the following heights: foxtails, fall panicum - up to 3 inches tall; barnyardgrass - up to 4
inches; quackgrass, wirestem muhly - up to 10 inches; shattercane - up to 12 inches; johnsongrass - up to 16 inches.
? Apply is a spray volume of 10 to 20 gpa with a methylated seed oil (1.5 pts/A) plus 28% UAN (1.5 to 2 qts/A) or ammonium
sulfate (1.5 to 3 lbs/A). For spray volumes of 15 gpa or more, the methylated seed oil rate can be 1% v/v.
? Do not use Option in the same season as Thimet. Application of Option following an at-planting Lorsban application may result
in temporary crop injury. Foliar applications of an organophosphate insecticide should not occur within 7 days of Option
application.
Herbicide Formulation Product Rate Range
Permit 75DF 2/3 to 1 1/3 oz
Tank-mix with: Dicamba, dicamba+atrazine, 2,4-D, bromoxynil, Buctril+atrazine, Atrazine, Accent, Beacon, Steadfast,
Steadfast ATZ.
? Permit (halosulfuron) is a translocated sulfonylurea herbicide that controls yellow nutsedge and annual broadleaf weeds,
including velvetleaf, ragweeds, cocklebur, and redroot pigweed. Permit is weak on lambsquarters and annual morningglories.
A combination of Permit plus dicamba will improve control of these weeds and control or suppress perennial broadleaf weeds.
Does not control ALS-resistant weeds.
? Mode of action: ALS inhibitor.
? Apply when field corn is in the spike through layby stage and most annual weeds are 1 to 6 inches tall for best results. When
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Corn: Postemergence Herbicides — Systemic
corn is more than 24 inches tall, tank-mixes of Permit with other postemergence corn herbicide should be applied with drop
nozzles to ensure weed coverage and avoid spraying directly into the whorl. Follow the most restrictive label with regard to
maximum corn size when tankmixing.
? Permit can be applied broadcast (2/3 oz/A) to sweet corn and popcorn in the spike through layby stage. Two applications are
allowed per year, but the second should be applied with drop nozzles. Sweet corn and popcorn hybrids should be thoroughly
tested for sensitivity to Permit before treating large acreages. Do not apply to the sweet corn variety 'Jubilee'. Do not apply
when corn is under stress from environmental conditions.
? For control of yellow nutsedge, apply 1 to 1 1/3 ounces/A when nutsedge is 4 to 12 inches tall. Dense populations of nutsedge
may require a second application.
? Apply in a minimum spray volume of 10 gpa with nonionic surfactant (1 to 2 quarts/100 gallons) or crop oil concentrate (1
gallon/100 gallons). Include nitrogen fertilizer solution (2 to 4 quarts/A) or AMS (2 to 4 lbs/A) when velvetleaf or redroot
pigweed is present.
? Tank mixtures may cause temporary crop injury, especially when the tank-mix partner is Accent or Beacon. Do not apply in a
tank-mix if the crop is under stress due to drought, water saturated soils, low fertility, hail, frost, insects, or when the maximum
daytime temperature is above 92 degrees.
Herbicide Formulation Product Rate Range
Priority 62.5DF 1 oz
Tank-mix with: Most other herbicides - see labels.
? Priority is a premix of halosulfuron (Permit) plus carfentrazone (Aim) for postemergence control of broadleaf weeds and suppression
of yellow nutsedge. See Permit and Aim descriptions for more information.
? Mode of action: ALS inhibitor (halosulfuron); cell membrane disruptor (carfentrazone).
? Can be applied to field corn, popcorn, seed corn, and sweet corn from emergence up to the 8-collar stage. Weeds should be
less than 4 inches tall for best results.
? Apply with nonionic surfactant (0.25% v/v). Ammonium sulfate (2-4 lbs/A) or 28% UAN (2-4 qts/100 gallons) can be added,
but will increase the severity of leaf speckling from the carfentrazone.
Herbicide Formulation Product Rate Range
Shotgun 3.25L 2 - 3 pints
? Shotgun is a premix of atrazine plus 2,4-D for postemergence control of many broadleaf weeds in corn.
? Mode of action: photosynthesis inhibitor (atrazine), growth regulator (2,4-D).
? Apply broadcast in a minimum spray volume of 10 gpa when corn is spike to 8 inches tall, and as a directed spray when corn is
8 to 12 inches tall. Treated corn may be brittle and subject to breakage by wind during the 2 weeks following application.
? Allow 6 hours between application and rainfall.
? Follow precautions to prevent drift and volatility of 2,4-D, which will injure nearby broadleaf plants. Volatility is more likely
at air temperatures greater than 85 degrees.
Herbicide Formulation Product Rate Range
Spirit 57DF 1 oz (1 packet per 4 acres)
Tank-mix with: Dicamba, 2,4-D, atrazine, bromoxynil, Buctril+atrazine, dicamba+atrazine, Beacon, Accent, Steadfast,
Steadfast ATZ.
? Spirit is a premix of prosulfuron (Peak) plus primisulfuron (Beacon), translocated sulfonylurea herbicides. The weed control
spectrum of Spirit is similar to Exceed, but Spirit is likely to be less effective on lambsquarters and a few other broadleaf
weeds. Tank-mixing with dicamba, 2,4-D, or Buctril/Moxy will improve annual weed control. Most effective control/suppression
of perennial broadleaf weeds will occur when tank-mixed with 2,4-D or dicamba. Spirit is weak on annual morning64
glories and yellow nutsedge. Does not control ALS-resistant weeds.
? Mode of action: ALS inhibitor.
? Most of the guidelines and label directions for Spirit use are similar to those for Exceed.
? Follow these guidelines to avoid carryover of Spirit to subsequent crops: 1) Avoid use where soil pH is greater than 7.8. If
used where soil pH is greater than 7.8, plant only field corn or small grains the following year; 2) where less than one inch of
rain occurs within one month of application, or less than 12 inches of rain occurs within 5 months after application, plant only
corn, small grains, or STS soybeans the following year ; 2) north of Interstate 80, do not plant soybeans within 18 months of
application; 3) south of I-80, soybeans can be planted 10 months after application where soil pH is less than 7.8; and 4) do not
apply after June 30. See label for guidelines on rotation to other crops.
? Apply broadcast or directed when field corn is 4 to 24 inches tall. To avoid injury and improve spray coverage on weeds, apply
as a directed spray using drop nozzles when corn is more than 20 inches tall.
? For popcorn, apply as a directed spray using drop nozzles when corn plants are 10 to 24 inches tall, and before tassel emergence.
For seed corn inbreds, Spirit can be applied broadcast when corn is between 4 and 20 inches tall, or until the 6-collar
stage, whicever occur first. Use drop nozzles when seed corn inbreds are 20 to 24 inches tall and before tassel emergence.
Inbred lines and popcorn hybrids should be thoroughly tested for sensitivity to Spirit before treating large acreages. Do not
apply to sweet corn.
? Apply in a minimum spray volume of 10 gpa. Increasing the volume to at least 20 gpa can improve control in dense weed
infestations.
? Apply with crop oil concentrate (1 to 4 pints/A) or nonionic surfactant (1 to 2 quarts/100 gallons). Liquid nitrogen fertilizer (2
to 4 quarts/A) or AMS (2 lbs/A) may be added to improve control of velvetleaf and other weeds. Crop oil concentrate is generally
more effective than nonionic surfactant. Use of a methylated seed oil (Meth Oil, Priority MSO, Sun-It II, for example)
may improve control when weeds are large or drought-stressed.
Herbicide Formulation Product Rate Range
Starane 1.5L 2/3 pt
Tank-mix with: See labels.
? Starane (fluroxypyr) is a translocated herbicide that controls hemp dogbane, common ragweed and a few other broadleaf
weeds. Due to a relatively narrow spectrum of activity, Starane should be mixed with other herbicides to improve control of
specific problem weeds.
? Mode of action: growth regulator.
? Apply broadcast up to the V5 stage of field corn and when weeds are less than 8 inches tall. Applications when corn is past the
V5 stage should be made as a directed spray using drop nozzles.
? Crop injury, including stem curvature, stunting, and brace root injury can occur with some corn hybrids when Starane is applied
as a broadcast treatment. Hybrids susceptible to phonoxy injury may also be susceptible to injury from Starane.
Herbicide Formulation Product Rate Range
Steadfast 75DF 3/4 oz
Tank-mix with: Distinct, Stinger, atrazine, dicamba, Marksman, Hornet, Callisto, Exceed, Spirit, Yukon, Permit.
? Steadfast is a 2:1 premix of nicosulfuron (Accent) plus rimsulfuron, translocated sulfonylurea herbicides, that controls annual
and perennial grasses, including foxtails, fall panicum, quackgrass, and shattercane. Steadfast will control large crabgrass up
to one inch tall. Steadfast also controls small annual morningglory, pigweed, Pennsylvania smartweed, and sunflower. Application
of Steadfast with Distinct, Clarity, or Marksman will suppress or control many perennial broadleaf weeds.
? Mode of action: ALS inhibitor.
? Can be applied broadcast or as a directed spray to field corn that is up to 20 inches tall or up to 6 collars (whichever comes
first).
? Do not apply to popcorn, or sweet corn, or corn grown for seed (inbreds).
? OSU research has shown it can be difficult to achieve adequate season-long weed control with a single postemergence application
of herbicides with limited residual activity (such as Steadfast). Applying a reduced rate of a preplant or preemergence herbicide
prior to postemergence application of Steadfast will result in more consistent control of longer duration.
? For best results, apply with crop oil concentrate (1 gallon/100 gallons spray) plus nitrogen fertilizer solution (28% - 2 quarts/
Corn: Postemergence Herbicides — Systemic
65
A) or ammonium sulfate (2 lbs/A). Substituting a methylated seed oil (Meth Oil, Priority MSO, Sun-It II, for example) for
crop oil concentrate can improve control under drought-stressed conditions. Nonionic surfactant (1 to 2 qts/100 gallons spray)
can be used instead of crop oil if required in a tank-mix with another herbicide, but grass control may be reduced.
? Apply in a spray volume of at least 15 gpa with a pressure of 20 to 40 psi. Avoid spraying excessive amounts of herbicide
directly into the corn whorl.
? Apply when grasses are at the following heights: foxtails, fall panicum, and barnyardgrass — up to 4 inches; quackgrass — 4
to 8 inches; shattercane — up to 6 inches; seedling johnsongrass — up to 8 inches.
? Control may be reduced if applied during conditions of drought stress, abnormally hot or cold weather, when nighttime temperatures
are less than 40 degrees, or following periods of large day/night temperature fluctuations.
? Where Steadfast is applied to corn previously treated with soil applications of organophosphate insecticides, temporary crop
injury may occur. Application of Steadfast to corn treated with Thimet may cause severe crop injury.
? Do not apply Steadfast with foliar-applied organophosphate insecticides or with Basagran, Laddok, or 2,4-D. Do not apply
these materials within 7 days before through 3 days after applying Steadfast.
Herbicide Formulation Product Rate Range
Steadfast ATZ 89.3DF 14 oz
Tank-mix with: atrazine, dicamba, Distinct, Callisto, Hornet WDG, Exceed, Spirit, Stinger, Yukon, Permit.
? Steadfast ATZ is a premix of nicosulfuron, rimsulfuron, and atrazine for control of broadleaf and grass weeds.
? Mode of action: ALS inhibitor (nicosulfuron, rimsulfuron); photosynthetic inhibitor (atrazine).
? Can be applied to field corn up to 12 inches tall or up to and including 6 collars (whichever occurs first).
? Do not apply to popcorn, sweet corn, or corn inbreds.
? Steadfast ATZ controls many annual broadleaf and grass weeds up to 4 inches tall. A tankmix partner is required for taller
weeds or broader spectrum of control.
? See atrazine and Steadfast descriptions for other information and precautions.
Herbicide Formulation Product Rate Range
Stinger 3L 1/4 - 2/3 pt
Tank-mix with: Bromoxynil, Buctril+atrazine, Laddok, Hornet.
? Stinger (clopyralid) is a translocated herbicide that controls ragweeds, cocklebur, jimsonweed, and Canada thistle. Controls or
suppresses Jerusalem artichoke and suppresses sowthistle.
? Mode of action: growth regulator.
? Apply after corn emergence until corn is 24 inches tall in a spray volume of at least 10 gallons per acre.
? For annual weed and Jerusalem artichoke control, apply 1/4 to 1/2 pint when weeds have 5 or fewer leaves.
? For Canada thistle control, apply 1/3 to 2/3 pint when thistles are at least 4 inches tall or across, but before the bud stage. The
higher rate provides more complete plant kill and better control of dense patches. Do not cultivate prior to or for 14 to 20 days
following application. Although control of thistle with Stinger during the season of application may appear similar to that from
other corn herbicides, Stinger provides more complete kill of the entire plant (at a greater cost).
Herbicide Formulation Product Rate Range
WideMatch 1.5L 1.3 pts
Tank-mix with: See labels.
? WideMatch is a premix of clopyralid (Stinger) plus fluroxypyr (Starane) for control of broadleaf weeds in corn, including
hemp dogbane, ragweeds, Canada thistle, marestail, and cocklebur.
? Mode of action: growth regulator.
? Apply broadcast up to the V5 stage of field corn and when weeds are less than 8 inches tall. Applications when corn is past
the V5 stage should be made as a directed spray using drop nozzles.
? Crop injury, including stem curvature, stunting, and brace root injury can occur with some corn hybrids when WideMatch is
Corn: Postemergence Herbicides — Systemic
66
applied as a broadcast treatment. Hybrids susceptible to phonoxy injury may also be susceptible to injury from WideMatch.
? For most effective Canada thistle control, apply after the majority of the basal leaves have emerged and before bud stage.
Herbicide Formulation Product Rate Range
Yukon 67.5WG 4 to 8 oz
Tank-mix with: atrazine, Accent, Beacon.
? Yukon is a premix of halosulfuron (Permit) plus dicamba for control of most annual broadleaf weeds and yellow nutsedge.
Yukon will also suppress/control some perennial broadleaf weeds, primarily during the growing season of application.
? Mode of action: ALS inhibitor (halosulfuron); growth regulator (dicamba).
? Can be applied broadcast or with drop nozzles from the spike stage through 36 inch-tall corn. Weeds should generally be less
than 6 inches tall for best results. Use a rate of 6 to 8 oz for yellow nutsedge control.
? Apply with nonionic surfactant (1 to 2 quarts/100 gallons) or crop oil concentrate (1 gallon/100 gallons). Crop oil concentrate
may cause injury at the higher Yukon rates. Nitrogen fertilizer solution (28% UAN, etc - 2 to 4 quarts/A) or ammonium sulfate
(2 to 4 lbs/A) can be added to improve control of certain weeds or if required for another herbicide in the spray mix. Apply in a
spray volume of at least 10 gpa.
? Most of the precautions and restrictions on use of Permit and Banvel apply to Yukon also. See Permit and Banvel descriptions
for more information.
Herbicide Formulation Product Rate Range
2,4-D LV Ester Various 0.17 - 0.25 lb ai/A
2,4-D Amine Various 0.34 - 0.5 lb ai/A
Tank-mix with: Atrazine, dicamba, bromoxynil, Beacon, Sencor, Permit, Exceed.
? Mode of action: growth regulator.
? Controls many annual broadleaf weeds, including ragweeds, cocklebur, lambsquarters, and pigweed. Will control or suppress
perennial broadleaf weeds, especially when applied with Beacon, Exceed, Spirit, or Permit.
? For best results, apply when weeds are small.
? If corn is more than 8 inches tall, use drop nozzles to reduce the risk of crop injury. Do not apply from the tasseling stage to the
dough stage.
? Use precautions to prevent drift. The ester forms of 2,4-D can volatilize and injure nearby susceptible plants, including soybeans
and vegetable crops. Amine formulations are less volatile than ester formulations, and should generally be used for postemergence
applications in corn.
? Injury may result when applied to corn growing rapidly under high temperatures and high humidity. Corn may be brittle for 7 to
10 days after application, and is susceptible to stalk breakage from high winds or cultivation.
Clearfield Corn: Postemergence Herbicides
Corn: Postemergence Herbicides — Systemic
67
Herbicide Formulation Product Rate Range
Lightning 70DF 1.28 oz
Tank-mix with: Bromoxynil, dicamba, 2,4-D, dicamba+atrazine, Distinct. atrazine, Shotgun, Laddok S-12, Buctril+atrazine.
? Lightning is a premix of imazethapyr (Pursuit) plus imazapyr for postemergence use on field corn hybrids that are tolerant to
Pursuit and other imidazolinone herbicides. Use only on hybrids labeled as "Clearfield" or "imidazolinone-tolerant".
? Mode of action: ALS inhibitor.
? Lightning is similar to Pursuit in weed control spectrum, but has longer residual activity and is more effective on lambsquarters.
Control of common and giant ragweed is variable. Tank-mixes of Lightning with Distinct will improve control of
ragweeds, lambsquarters, and perennial broadleaf weeds. Lightning does not control ALS-resistant weeds when applied alone.
? OSU research has shown it can be difficult to achieve adequate season-long weed control with a single postemergence application
of herbicides with limited residual activity. Applying Lightning with atrazine or following a reduced rate of a preplant or
preemergence herbicide will result in more consistent control of longer duration. In fields with heavy grass pressure, use of a
preemergence grass herbicide prior to postemergence use of Lightning is recommended.
? Apply before most annual weeds exceed 3 inches in height. Cocklebur, pigweed, shattercane, and seedling johnsongrass can be
up to 8 inches tall. For control or suppression of Jerusalem artichoke, apply when plants are 6 to 10 inches tall.
? Apply with nonionic surfactant (1 quart/100 gallons spray) plus nitrogen fertilizer solution (1 to 2 quarts/acre) or ammonium
sulfate (2.5 lbs/A). Control of drought-stressed weeds will be maximized when the higher rates of fertilizer are used.
? Apply broadcast to corn up to 20 inches tall or the V6 stage, and as a directed spray until 45 days before harvest. Broadcast
applications of Lightning when corn is more than 20 inches tall or past the V6 stage can result in poor kernel set and reduced
yield. When tank-mixing Lightning with other herbicides, always follow the more restrictive label with regard to spray additives,
maximum crop size, and other precautions.
? Control may be reduced when weeds are growing slowly under cold or dry conditions. If possible, wait for rain and resumption
of active weed growth before applying Lightning. If air temperatures reach or stay below 50 degrees F for 10 or more
hours, delay application for 48 hours from the time temperatures increase above 50 degrees F.
? Thimet may be applied only in a band where Lightning will be applied postemergence.
Liberty Link Corn — Postemergence Herbicides
68
Herbicide Formulation Product Rate Range
Liberty 1.67L 28 - 34 oz
Tank-mix with: Most other corn herbicides - see labels.
? Liberty (glufosinate) is a contact, broad-spectrum herbicide for postemergence use only on Liberty Link (glufosinate-resistant)
corn.
? Mode of action: glutamine synthetase inhibitor.
? Liberty controls many annual grass and broadleaf weeds up to 4 to 8 inches tall when applied at a rate of 28 to 34 oz per acre.
Mixing with atrazine improves control of many weeds, including pigweeds, waterhemp, velvetleaf, annual morningglories,
and lambsquarters, and provides several weeks of residual control.
? Maximum height for grass weeds at the 32 oz/A rate: barnyardgrass, crabgrass, yellow foxtail, fall panicum - 3 inches;
woolly cupgrass, shattercane, and green, giant, and robust foxtails - 6 inches; volunteer corn - 10 inches. Yellow foxtail and
crabgrass should be treated prior to tiller initiation for best results.
? Maximum height for broadleaf weeds at the 32 oz/A rate: lambsquarters, pigweeds, waterhemp - 4 inches; velvetleaf - 5
inches; burcucumber, chickweed, cocklebur, marestail, annual morningglories, black nightshade, ragweeds, and Pennsylvania
smartweed - 6 inches.
? Liberty plus atrazine (1 lb ai/A) will control or suppress some perennial weeds, including dandelion, Canada thistle, Jerusalem
artichoke, and wirestem muhly. Liberty has activity on above-ground growth only, so regrowth of perennials may occur and
retreatment may be necessary.
? Apply with ammonium sulfate (3 lbs/A or 17 lbs/100 gallons). Do not use surfactants or crop oils with Liberty when applied
alone or in tank-mixes.
? Apply broadcast from corn emergence until corn is 24 inches tall or has 7 collars, whichever occurs first. Apply as a directed
spray using drop nozzles when corn is 24 to 36 inches tall.
? OSU research indicates that Liberty is most effective in a combined preemergence plus postemergence program, where the
preemergence herbicide will provide control of grass and broadleaf weeds for several weeks after corn planting. Examples of
preemergence herbicides used in this approach include Balance plus atrazine, simazine + atrazine, and reduced rates of premix
products such as Epic, Bicep, Degree Xtra, etc. Postemergence applications of Liberty in this program should include atrazine
(1 lb ai/A) where possible.
? Apply in a minimum of 15 gpa with a pressure of 30 to 40 psi. Use a volume of 20 gpa in dense weed/crop canopies. Flat fan
nozzles are recommended.
? Liberty is most effective when applied under warm, sunny conditions. Effectiveness may be reduced if applied when heavy
dew, fog and mist/rain are present, or if weeds are under stress due to drought, cool temperatures, or extended periods of
cloudiness. To avoid reduced control of velvetleaf and lambsquarters, apply between dawn and two hours before sunset.
Herbicide Formulation Product Rate Range
Liberty ATZ 4.3L 40 - 48 oz
Tank-mix with: most other postemergence corn herbicides - see label.
? Liberty ATZ is a premix of Liberty (glufosinate) plus atrazine for postemergence use only on Liberty Link (glufosinate-resistant)
corn. See Liberty description for more information on use of this herbicide combination.
? Mode of action: glutamine synthetase inhibitor (glufosinate); photosynthesis inhibitor (atrazine).
? Apply from corn emergence until corn is 12 inches tall.
Roundup Ready Corn — Postemergence Herbicides
69
Herbicide Formulation Product Rate Range
Expert 4.88L 2.5 - 3.75 qts
Tank-mix with: Roundup WeatherMax
? Expert is a premix of glyphosate, s-metolachlor (Dual II Magnum), and atrazine that can be applied postemergence to Roundup
Ready corn. This application controls emerged weeds and provides residual activity for later-emerging weeds.
? Mode of action: EPSP synthase inhibitor (glyphosate), photosynthesis inhibitor (atrazine), shoot meristem inhibitor (s-metolachlor).
? Can be applied until corn reaches a height of 12 inches. Apply when weeds are 4 inches tall or less to minimize weed competition
with corn.
? Reduced rates of this product can be used, but may need to be mixed with additional amounts of glyphosate for adequate control
of emerged weeds.
? The addition of ammonium sulfate (17 lbs/100 gallons) is not required, but can improve effectiveness when using hard water
or when weeds are growing under adverse environmental conditions.
Herbicide Formulation Product Rate Range
Field Master 4L 2 - 4 qts
Tank-mix with: Roundup WeatherMax
? Field Master is a premix of glyphosate, acetochlor (Harness), and atrazine that can be applied postemergence to Roundup
Ready corn. This application controls emerged weeds and provides residual activity for later-emerging weeds.
? Mode of action: EPSP synthase inhibitor (glyphosate), photosynthesis inhibitor (atrazine), shoot meristem inhibitor (acetochlor).
? Can be applied until corn reaches a height of 11 inches. Apply when weeds are 4 inches tall or less to minimize weed competition
with corn.
? Reduced rates of this product can be used, but may need to be mixed with additional amounts of Roundup WeatherMax for
adequate control of emerged weeds.
? The addition of ammonium sulfate (17 lbs/100 gallons) is not required, but can improve effectiveness when using hard water
or when weeds are growing under adverse environmental conditions.
Herbicide Formulation Product Rate Range
Ready Master ATZ 4L 1.5 - 2 qt
Tank-mix with: Atrazine, Harness, Micro-Tech
? Ready Master ATZ is a premix of atrazine plus glyphosate that controls emerged weeds and provides residual broadleaf weed
control. Can be applied postemergence in Roundup Ready corn only.
? Mode of action: photosynthesis inhibitor (atrazine), EPSP synthase inhibitor (glyphosate).
? Apply when weeds are 2 to 4 inches tall. Use the higher rate for control of fall panicum and Pennsylvania smartweed, in dense
weed populations, and where targeting perennial weeds.
? Apply in a spray volume of 10 to 25 gpa before corn exceeds 12 inches in height.
? The addition of ammonium sulfate (17 lbs/100 gallons) is recommended when tank-mixing with residual corn herbicides,
when weeds are subject to stress from cool temperatures or other factors, and when hard or high pH water is used as the carrier.
Herbicide Formulation Product Rate Range
70
Glyphosate Various 0.56 - 0.75 lb acid/A
Tank-mix with: See labels.
? Glyphosate is a translocated herbicide that controls emerged annual and perennial grass and broadleaf weeds. Table 22 contains
a list of currently available glyphosate products. Variations in the formulation may result in differences in product rate,
adjuvant recommendations, and rainfastness. Users should consult labels and local product use guides for more specific information.
Apply postemergence only to corn hybrids designated as Roundup Ready.
? Mode of action: EPSP synthase inhibitor.
? Most glyphosate products can be applied broadcast or directed from corn emergence through the 8-collar stage or until corn is
30 inches tall, whichever occurs first. A number of glyphosate products can be applied to Roundup Ready Corn 2 (Roundup
Ready 603 corn) up to 48 inches tall with drop nozzles adjusted to keep spray out of corn whorls.
? The general recommendation on most labels for the initial postemergence application is a rate of 0.75 lbs of glyphosate acid
per acre when weeds are less than 4 to 8 inches tall (see Table 22 for product rates). Sequential applications are allowed.
Maximum use rates per application and the total amount that can be applied postemergence in one season varies with product
and the type of Roundup Ready corn. Higher rates are allowed on Roundup Ready Corn 2 (Roundup Ready 603 corn), compared
to other types of Roundup Ready corn.
? OSU research shows that a single postemergence application of glyphosate is not likely to provide adequate weed control
except where weed populations are extremely low. One of the following strategies is recommended for consistent control: 1)
application of a preplant or preemergence herbicide (at approximately half the labeled rate) prior to postemergence glyphosate
application, or 2) early postemergence application of glyphosate in a tank-mix with herbicides that provide residual control
(atrazine, Harness Xtra, Bicep, etc). Maximum height of corn at the time of application varies with the tank-mix partner.
? Velvetleaf is most easily controlled when less than 4 inches tall and actively growing. Large velvetleaf can be difficult to
control with glyphosate, especially when drought-stressed. The addition of ammonium sulfate (8.5 to 17 lbs/100 gallons) will
improve control of velvetleaf and some other weeds. Ammonium sulfate will also improve control when using hard water,
when daytime air temperatures are 55 degrees or less, and when tank-mixing with Bullet, Micro-tech, or Partner.
? Annual morningglory, groundcherry, lambsquarters, and Pennsylvania smartweed are more difficult to control than other annual
weeds, and glyphosate should be applied when weeds are less than 6 inches tall for best results.
? Control of perennial weeds will require higher rates than annual weeds. Application when perennials are in the bud to bloom
stage (or boot to seedhead for grasses) will provide the most complete control of the entire plant. Minimum size of various perennial
weeds for most effective control through the growing season: quackgrass, Canada thistle, wirestem muhly, and yellow
nutsedge - 6 inches; field bindweed and common milkweed -12 inches; johnsongrass and hemp dogbane - 18 inches.
? Apply in a spray volume of 5 to 20 gpa. Using a volume of 15 to 20 gpa, selecting the appropriate nozzles, and reducing spray
pressure will reduce the potential for spray drift. Take precautions to reduce spray drift, since corn, soybeans, and other sensitive
crops are likely to be growing in areas surrounding treated fields.
Corn: Harvest Aids
Roundup Ready Corn — Postemergence Herbicides
71
Herbicide Formulation Product Rate Range
Glyphosate Various Up to 1.12 lbs glyphosate acid (ground application)
Up to 0.75 lbs glyphosate acid (aerial application)
? Many glyphosate products can be applied as a preharvest treatment to control perennial and annual weeds in corn. Consult labels
for specific recommendations on use rate, adjuvant use, and rainfast intervals.
? Preharvest applications of glyphosate may provide a good opportunity to control perennial weeds because their growth is undisturbed
compared to postharvest applications.
? Mode of action: EPSP synthase inhibitor.
? Apply when grain moisture is 35 percent or less. Corn should be physiologically mature (black layer formed) with maximum
kernel fill complete. Apply at least 7 days before harvest.
? Depending upon the glyphosate product, the label prohibits or recommends avoiding preharvest application to corn grown for
seed, due to the potential for a reduction in germination or vigor.
Herbicide Formulation Product Rate Range
Gramoxone Max 3L 1.3 pt
? Gramoxone Max (paraquat) may be used for drying weeds in field corn, seed corn, and popcorn just before harvest. Apply when
corn is mature - after the black layer has formed at the base of the kernels.
? Mode of action: cell membrane disruptor.
? Mature cocklebur and lambsquarters are tolerant of Gramoxone and may not desiccate completely.
? For aerial application, use a spray volume of 5 gallons per acre; for ground application, use 20 gallons per acre. Add nonionic
surfactant (0.25% v/v) or crop oil concentrate (1% v/v).
? Apply at least 7 days before harvest.
Soybeans: Soil-Applied Herbicides — Preplant Incorporated Only
72
Table 6. Grazing and Forage (Silage, Hay, etc.) Intervals for Herbicide-Treated Corn
This table is a guide for grazing and feeding herbicide-treated corn, and shows the time that should occur between herbicide application and
grazing or harvest for silage. For premixes or combinations not listed below, the minimum interval equals the longer of the two intervals for each
individual product in the mix. Always consult herbicide labels for specific limitations.
Herbicide Grazing Forage (silage, etc.)
2,4-D 7 days 7 days
Accent SP 30 days 30 days
Aim none none
Atrazine 21 days 21 days
Axiom none none
Balance Pro none none
Basagran 12 days None
Basis Gold/Basis 30 days 30 days
Beacon 30 days 45 days
Bicep II Magnum/Cinch ATZ 30 days 30 days
Bromoxynil 30 days 30 days
Callisto Do not graze 45 days
Celebrity Plus 32 days 32 days
Define None None
Degree 21 days 21 days
Degree Xtra 21 days 21 days
Dicamba Past “milk” stage Past “milk” stage
Dicamba+atrazine Past “milk” stage Past “milk” stage
Distinct 32 days 32 days
Dual II Magnum/Cinch 30 days 30 days
Epic None None
Equip 45 days 45 days
Exceed 30 days 40 days
Expert 60 days 60 days
Field Master 56 days 56 days
FulTime 21 days 21 days
Gramoxone Extra (at planting) None None
Guardsman Max 40 days 40 days
Harness 21 days 21 days
Harness Xtra 21 days 21 days
Hornet 85 days 45 days
Keystone 21 days 21 days
Laddok 21 days 21 days
Lariat/Bullet 21 days 21 days
Lasso/Micro-Tech None None
Liberty 70 days 60 days
Liberty ATZ 30 days 40 days
Lightning/Pursuit 45 days 45 days
Lumax/Lexar 45 days 45 days
Northstar 30 days 45 days
Option 45 days 45 days
Outlook 60 days 60 days
Parallel 30 days 30 days
Permit 30 days 30 days
Princep/simazine Do not graze None
Priority 30 days 30 days
Prowl/Pendimax None None
73
Table 6. (continued)
Herbicide Grazing Forage (silage, etc.)
Python 85 days 85 days
Ready Master ATZ 50 days 50 days
Resource 28 days 28 days
Roundup WeatherMax, Glyphomax, other glyphosates 50 days 50 days
Sencor 60 days 60days
Shotgun 21 days 21 days
Spirit 30 days 40 days
Stalwart C, Stalwart Xtra 30 days 30 days
Starane 47 days 47 days
Steadfast 30 days 30 day
Steadfast ATZ 60 days 60 days
Surpass/Topnotch 21 days 21 days
Stinger 40 days 40 days
Touchdown 50 days 50 days
WideMatch 47 days 47 days
Yukon 30 days and past "milk" stage 30 days and past "milk" stage
74
Table 7. Rainfast Intervals, Spray Additives, and Maximum Crop Size for Postemergence Corn Herbicides
This table shows the required time interval between herbicide application and rainfall and summarizes label recommendations for
spray additives and maximum crop stage. Check herbicide labels for additive rates. Information in this table applies to field corn
only. Use the following key for spray additives:
SURF = nonionic surfactant
COC = crop oil concentrate
DASH = BASF spray adjuvant
UAN = 28% nitrogen solution
AMS = ammonium sulfate
MSO = Methylated seed oil
Herbicide Rainfast Spray additives/Maximum Crop Size
Interval
(hours)
2,4-D Amine 6-8 No additives. Broadcast up to 8-inch corn; directed spray before tassel stage.
2,4-D Ester 2-3 No additives. Broadcast up to 8-inch corn; directed spray before tassel stage.
Accent 4 MSO, COC or SURF (Addition of UAN or AMS is recommended). Broadcast up to 6 collars or
20-inch corn; directed spray up to 10 collars or 36-inch corn.
Accent + Atrazine 4 MSO or COC + UAN or AMS. Apply before corn is 12 inches tall.
Accent + dicamba 6-8 SURF. Addition of UAN or AMS is recommended. Broadcast before corn is 8 inches tall;
directed spray up to 24-inch corn.
Accent + bromoxynil 4 SURF. UAN, 10-34-0 or AMS is recommended. Broadcast up to 6 collars or 20-inch corn;
directed spray up to 10 collars or 36-inch corn.
Accent + dicamba/atrazine 6-8 SURF. Addition of AMS or UAN is recommended. Apply before corn is 8 inches tall.
Aim 1 SURF. AMS or UAN may be added if required by tank-mix partner. Do not use COC or tankmix
with EC formulations of other crop protection chemicals except as specifically directed by
label. Apply up to 8-collar corn.
Atrazine 2 MSO or COC. Apply before corn is 12 inches tall.
Basagran 8 COC, MSO, UAN, or AMS or COC or MSO + UAN or AMS, depending on weed species present.
Basis 4 MSO, COC, or SURF + UAN or AMS. Apply before corn reaches the 3 collar stage.
Basis Gold 4 MSO or COC. Addition of UAN, 10-34-0, or AMS is recommended. Apply before 12-inch
corn or before 6 collars, whichever is more restrictive.
Basis Gold + dicamba 6-8 MSO or COC. Addition of UAN, 10-34-0, or AMS is recommended. Apply before 12-inch
corn or before 6 collars, whichever is more restrictive.
Beacon 4 MSO, COC, or SURF (UAN or AMS may be added). Broadcast 4 to 20-inch corn; directed
spray before tassel emergence.
Bromoxynil 1 No additives. Apply before tassel emergence.
Bromoxynil+atrazine 2 No additives. Apply before corn is 12 inches tall.
Callisto 1 COC + UAN or AMS. Apply up to 30-inch or 8-leaf corn.
Callisto + atrazine 2 COC + UAN or AMS. Apply before 12-inch corn.
Celebrity Plus 4 SURF + UAN, 10-34-0, or AMS. Broadcast up to 6 collars or 24-inch corn.
Dicamba 6-8 Add UAN if velvetleaf is present. SURF, COC, or UAN may be added under dry conditions.
Do not apply with COC when corn height exceeds 5 inches. Broadcast up to 5th-leaf stage or
8-inch corn; directed spray up to 36-inch corn.
Dicamba/atrazine 6-8 Add UAN if velvetleaf is present. SURF, COC, or UAN may be added under dry conditions.
Do not apply with COC when corn height exceeds 5 inches. Apply broadcast up to 5-leaf stage
or 8-inch corn.
Distinct 4 SURF + UAN or AMS. Apply 6 oz/A up to 10-inch corn, 4 oz/A up to 24-inch corn.
Equip 2 MSO +UAN or AMS. Broadcast up to 12 inch-corn or V4 stage, whichever occurs first. Directed
spray up to 36 inch-corn or V8 stage.
Exceed 4 MSO, COC, or SURF. UAN or AMS may be added. Broadcast from 4 to 20-inch corn;
directed spray up to 30-inch corn.
Exceed + Accent 4 MSO, COC, or SURF. UAN or AMS may be added. Broadcast up to 20-inch corn;
directed spray up to 36-inch corn.
Exceed or Spirit + dicamba 6-8 SURF. (If 1/8 pt/A of dicamba is used, then COC may be added in place of SURF)
Broadcast 4 to 12-inch corn; directed spray up to 24-inch corn.
Exceed or Spirit + 2,4-D 6-8 SURF. Do not add UAN or 10-34-0. Broadcast 4 to 8-inch corn; directed spray up to 24-inch
corn.
Exceed + bromoxynil 4 SURF. Do not add UAN. Broadcast 4 to 20-inch corn; directed spray up to 30-inch corn.
Glyphomax, Glyphomax Plus 1 AMS may be added. Apply up to 8 collar or 30-inch Roundup Ready corn.
Hornet 2 SURF, COC, or MSO. UAN or AMS may be added under extremely dry conditions. Broadcast
up to 20-inch corn or 6 collars.
Hornet + bromoxynil 6 SURF (or COC if allowed by bromoxynil label). UAN or AMS may be added under extremely
dry conditions. Broadcast up to 6 collars or 20-inch corn. Do not use this tank-mix if target
weeds are biennials or perennials.
Laddok 8 MSO, COC, UAN, AMS, DASH, or combinations of these. Apply before corn is 12 inches tall.
75
Herbicide Rainfast Spray additives/Maximum Crop Size
Interval
(hours)
Table 7. (continued)
Liberty 4 AMS. Broadcast up to 24-inch or 7-collar corn, whichever comes first; directed spray on 24 to
36 inch corn
Liberty ATZ 4 AMS (3.0 pounds/A) . Apply before 12-inch corn.
Lightning 1 SURF + UAN, 10-34-0 or AMS. Broadcast up to V6 or 20-inch corn; directed spray up to 45
days before harvest.
Lightning + atrazine 2 SURF + UAN, AMS, or 10-34-0. Apply before 12-inch corn.
Lightning + dicamba/atrazine 6-8 SURF + UAN, AMS, or 10-34-0. Apply before 8-inch corn.
Lightning + Distinct 4 SURF + UAN, 10-34-0 or AMS. Broadcast up to V6 or 20-inch corn.
Northstar 4 SURF, COC or MSO up to 12-inch corn. Only SURF between 12 and 36-inch corn. UAN or
AMS may be added. Broadcast 4 to 20-inch corn; directed spray up to 36-inch corn.
Option 4 MSO + UAN or AMS. Apply broadcast up to 16-inch or V5 stage; directed spray up to 36-inch
corn.
Permit 4 SURF, MSO, or COC. UAN or AMS may be added. Apply through layby stage of corn.
Permit + Accent 4 SURF, MSO, or COC. The addition of UAN or AMS is recommended. Broadcast up to 24-inch
corn; directed spray up to 36-inch corn.
Permit + dicamba 6-8 SURF. Broadcast up to 36-inch corn; directed spray after 8-inch corn will decrease injury.
Permit + 2,4-D 6-8 SURF. Broadcast up to 8-inch corn; directed spray through layby stage of corn.
Priority 6-8 SURF. AMS or UAN may be added. Broadcast or directed spray up to 8-collar stage.
Ready Master ATZ 2 AMS may be added. Apply up to 12-inch Roundup Ready corn.
Resource 1 COC. UAN or AMS may be added to improve control of certain species. Apply up to the 10-
leaf stage.
Roundup WeatherMax 0.5 AMS may be added. Apply up to 8 collar or 30-inch Roundup Ready corn.
Shotgun 6 No additives. Apply before 12-inch corn.
Spirit 4 COC, MSO or SURF.UAN or AMS may be added. Broadcast 4 to 20-inch corn; directed spray
up to 24-inch corn or after 6 collar corn.
Spirit + Accent 4 COC, MSO or SURF.UAN or AMS may be added. Broadcast 4 to 20-inch corn; directed spray
up to 24-inch corn.
Spirit + bromoxynil 4 SURF. Do not add UAN. Broadcast 4 to 20-inch corn; directed spray up to 24-inch corn.
Starane 1 An adjuvant can be used if required by tank-mix partner. Broadcast up to the V5 stage; directed
spray after the V5 stage.
Steadfast 4 COC, MSO, or SURF + UAN or AMS. COC or MSO is preferred over SURF. Broadcast up to
and including 6 collars or 20-inch corn
Steadfast ATZ 4 COC, MSO, or SURF + UAN or AMS. COC or MSO is preferred over SURF. Broadcast up to
and including 6 collars or 12-inch corn
Stinger 6-8 No additives. Up to 24-inch corn.
Touchdown 1 SURF and/or AMS may be added. Up to V8 stage of Roundup Ready corn.
WideMatch 6 No additives. Broadcast up to the V5 stage; directed spray after the V5 stage.
Yukon 4 SURF or COC. UAN or AMS may be added. Apply broadcast or directed up to 36-inch corn.
76
Field Corn Popcorn Sweet Corn
Field Corn
Grown For Seed
Table 8. Herbicides Labeled for Use on Field Corn, Seed Corn, Popcorn, and Sweet Corn
2,4-D Y Y5 Y5 Y
Accent Y Y5, 8 Y1, 5, 8 N
Aim Y Y9 Y Y5
Atrazine Y Y Y Y
Axiom Y Y N N
Balance Pro Y Y5 N N
Basagran Y Y Y Y
Basis Y N N N
Basis Gold Y6 N N N
Beacon Y5 Y5, 7 Y5, 7 N
Bicep II Magnum/Cinch ATZ Y Y Y Y
Bromoxynil Y Y2, 5 Y2 N
Callisto Y Y Y10 N
Celebrity Plus Y N N N
Define Y Y N N
Degree Y Y Y N
Degree Xtra Y Y Y N
Dicamba Y Y5 Y5 N
Dicamba+atrazine Y Y5 Y5 N
Distinct Y N Y N
Dual II Magnum/Cinch Y Y Y Y
Epic Y Y5 N N
Equip Y N N N
Exceed Y5 Y5, 7 Y5, 7 N
Expert Y Y Y Y
Field Master Y Y Y N
FulTime Y Y Y N
Guardsman Max Y Y Y Y5
Harness Y Y Y N
Harness Xtra Y Y Y N
Hornet Y Y5 N N
Keystone Y Y3 Y N
Laddok Y Y Y Y
Lariat/Bullet Y Y Y Y
Lasso/Micro-Tech Y Y Y Y4
Lumax/Lexar Y Y Y10 N
Northstar Y5 Y5, 7 Y5, 7 N
Option Y N N N
Outlook Y Y Y Y5
Parallel Y Y Y N
Permit Y Y Y Y5
Princep/simazine Y N N N
Priority Y Y Y Y5
Prowl Y Y Y Y
Pendimax Y N N N
Python Y Y5 N N
Resource Y Y N N
Sencor Y N N N
Shotgun Y N N N
Spirit Y5 Y5, 7 Y5, 7 N
Stalwart C/Stalwart Xtra Y Y Y N
Starane Y N N Y
Steadfast/Steadfast ATZ Y N N N
Stinger Y Y5 N N
Surpass/Topnotch Y Y Y N
WideMatch Y N N Y
Yukon Y Y N N
1 Do not apply to any white popcorn inbred or hybrid unless approved by seed supplier.
2 Do not apply prior to 3-leaf corn stage.
3 Do not use on corn seed stock such as “Breeders,” “Foundation,” or “Increase.”
4 Do not make postemergence application of Partner or Microtech to sweet corn.
5 Risk of injury - check with seed supplier or chemical representative for sensitivity of inbreds/hybrids.
6 Injury may occur on field corn hybrids with a Relative Maturity (RM) rating of less than 88 days or on waxy, Hi-Lysine, or food grade
corn.
7 Can be used if spray is directed using drop nozzles when seed corn is between 4 and 20 and 4 and 30 inches tall for Spirit and Exceed,
respectively, when popcorn is between10 and 24 and 10 and 30 inches tall for Spirit and Exceed respectively, and when seed corn and
popcorn are between 10 and 36 and 10 and 48 inches tall for Northstar and Beacon, respectively. All products must be applied before
tassel emergence.
8 Do not apply if corn is greater than 20 inches tall or exhibits 6 collars.
9 Apply as directed spray only. Avoid herbicide application into the corn whorl.
10 Yellow popcorn only.
77
Table 9. ALS Herbicide and Organophosphate Insecticide Use Precautions
This table is a guide to using ALS-inhibiting herbicides on "normal" and "Clearfield" field corn if an organophosphate (OP) insecticide is used
at planting. Do not tank-mix an OP insecticide with an ALS-inhibitor as severe injury will occur. Read the herbicide label before applying OP
insecticides postemergence if using ALS-inhibitors.
Definitions and Abbreviations:
Do not use = do not apply the herbicide if corn has been previously treated with soil insecticide.
NR = not recommended to apply the herbicide if corn has been previously treated with soil insecticide.
TI = Temporary injury may occur if the herbicide is applied to corn previously treated with soil insecticide.
Y = The herbicide can be used with nearly no risk of injury when applied to corn previously treated with soil insecticide.
Soil-applied Organophosphate Insecticides
Herbicide Counter 20CR Counter 20CR Thimet/ Lorsban Aztec
(in furrow) (banded) phorate
Accent Do not use NR TI TI Y
Basis Do not use NR NR TI TI
Basis Gold Do not use NR NR TI Y
Beacon Do not use NR TI TI TI
Celebrity Plus Do not use NR TI TI Y
Exceed Do not use NR TI TI TI
Equip Do not use See labels Do not use TI Y
Hornet (preemergence) Do not use Do not use Do not use TI1 TI1
Hornet (postemergence) Do not use Do not use Do not use TI TI
NorthStar Do not use NR TI TI TI
Option Do not use Do not use Do not use TI Y
Permit Y Y Y Y Y
Priority Y Y Y Y Y
Python Do not use Do not use Do not use TI1 TI1
Spirit Do not use NR TI TI TI
Steadfast/Steadfast ATZ Do not use NR NR TI Y
Yukon Y Y Y Y Y
Clearfield CORN Only
Lightning Do not use TI Do not use2 TI Y
1 The soil insecticide should be applied in a T-band or a band to avoid potential crop injury.
2 Do not use herbicide if soil insecticide is applied in furrow. Herbicide may be used if soil insecticide is applied in a band, but temporary corn
injury may still occur. | |
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best way to fry velvetleaf at tassle?
