Preplant, Preplant Incorporated, or Preemergence

acetochlor (Surpass or Cadence)

Consult label for corn uses or types

Rate 0.8 to 3 lb ai/a. Consult appropriate label for rates.

Time Apply preplant or preemergence.

Remarks Labels for the products differ. Follow the label for the product being used. Use lower rates on coarse soils with low organic matter. May be surface applied or incorporated into top 1 to 2 inches of soil. If rain or 0.25 to 0.75 inch of overhead irrigation does not occur within 7 days of a surface application, shallowly incorporate herbicide with a rotary hoe or similar device. May be tank mixed with several other herbicides to broaden activity.

Caution Improper incorporation methods or poor soil preparation may reduce weed control. Consult label for crop rotation restrictions.

Site of action Group 15: inhibits very long chain fatty acid synthesis

Chemical family Chloroacetamide

Acetochlor + Mesotrione (Harness Max)

Rate 1.12 - 1.92 lb ai/a Acetochlor + 0.096 - 0.18 lb ai/a Mesotrione (40-75 fl oz/a Harness Max)

Time Apply preplant, preemergence, or postemergence to field corn, seed corn, and yellow popcorn.

Remarks Harness Max is a premixture of acetochlor (HG 15) and mesotrione (HG 27). Postemergence applications can be made to corn up to 11 inches in height. Harness Max will provide excellent control of annual small-seeded broadleaf and grass weeds as well as postemergence control of some large-seeded broadleaf weeds. Use lower rate on coarse soils and lower organic matter (sand, sandy loams), higher rate on fine soils (silt loam, clays, silts) and soils high in organic matter. Consult label for compatible herbicide tankmix partners and adjuvants. Precipitation or overhead sprinkler irrigation is required after application to move the herbicide treatment into the weed germination zone in order to control weeds that have not emerged. The amount of moisture required for maximum activity depends on existing soil moisture, soil type, and organic matter content, but 0.5 to 0.75 inch is normally adequate.

Caution Do not apply to within 50 ft of any well where the depth of ground water is 30 ft or less. Field corn, seed corn, yellow popcorn, or grain sorghum can be planted immediately after application; wheat (4 months); alfalfa, peanuts, soybean, cotton (10 months); barley, rye, oats, millet (the spring following application); cucurbits, dry beans, peas, sugar beets and all other rotational crops (18 months). Refer to the label for all rotational restrictions. Do not apply to white popcorn, sweet corn, or ornamental (Indian) corn. Do not exceed a maximum of 3 lb ai/a of acetochlor from any product or combination of products containing acetochlor per year. Do not exceed a maximum of 0.24 ai/a of mesotrione from any product or combination of products containing mesotrione per year. Do not exceed a maximum of 0.19 lb ai/a of mesotrione applied postemergence from any product or combination of products containing mesotrione per year. Do not make more than 2 applications of this product per year (preemergence followed by postemergence or two postemergence applications are allowed). Only one postemergence application may be made if Harness Max has been used preemergence. Applications must be at least 14 days apart. Mixing Harness Max with organophosphate or carbamate insecticide will results in severe corn Injury.

Allow a minimum of 60 days before harvesting forage, grain, or stover or feeding corn forage to livestock

Site of action Groups 15 and 27: inhibiting very long chain fatty acid synthesis and 4-hydroxyphenylpyruvatedioxygenase (4-HPPD)

Chemical family Chloroacetamide + Triketone

atrazine (Aatrex 4L and several other trade names)

Rate 1.6 to 2 lb ai/a (2.5 lb ai/a maximum rate of product per season)

Time Apply preplant, preemergence, or postemergence when weeds are less than 1.5 inches tall.

Remarks Use lower rate on coarse soils (sand, sandy loams), higher rate on fine soils (silt loam, clays, silts) and soils high in organic matter. Overhead moisture required for maximum activity. East of the Cascades, postemergence applications may be made under sprinkler irrigation. Emerged annual grasses, such as barnyardgrass and green foxtail, are not adequately controlled when soil surface is dry at application and/or grasses are past the two-leaf stage. East of the Cascades, where rill irrigated, incorporate 2 inches deep before planting. If applying postemergence, control is enhanced by adding a nonionic adjuvant or a crop oil concentrate to the mix.

Caution A restricted-use herbicide. Plant only corn during the season of treatment. West of the Cascades, crops other than corn can be planted the year after treatment at 2 lb ai/a or less. East of the Cascades, do not plant any crop other than corn the year after treatment. Some populations of redroot pigweed, groundsel, kochia, and lambsquarters have evolved resistance to atrazine. Combine other herbicides with atrazine if these species are present. Do not graze treated area or feed treated forage to livestock for 21 days after application. After harvesting a treated crop, plow and thoroughly till the soil in the fall or spring to minimize possible injury to rotational spring-seeded crops.

Site of action Group 5: photosystem II inhibitor

Chemical family Triazine

dimethenamid-P (Outlook, Commit, Sortie)

Rate 0.47 to 0.98 lb ai/a (10 to 21 fl oz/a product)

Time Apply preplant or preemergence. May be applied at layby when corn is more than 12 inches tall but before it is more than 36 inches tall.

Remarks Consult label for application rate in relation to soil type. Use lower rates on coarse soils with low organic matter or low cation exchange capacity (CEC). Control is best when applied and incorporated into soil by overhead moisture or a light mechanical tillage before weed seedlings emerge. Till 1 to 2 inches deep to incorporate. May be tank mixed with atrazine or pendimethalin to improve broadleaf weed control. Consult the label for more options for tank-mixes to broaden weed control spectrum. May be applied through certain types of irrigation systems.

Caution Poor soil preparation or improper herbicide incorporation reduces weed control.

Site of action Group 15: inhibits very long chain fatty acid synthesis

Chemical family Chloroacetamide

flumioxazin (Chateau WDG)

Supplemental label for preplant residual in field corn only

Rate 0.188 to 0.38 lb ai/a (2 oz/a Chateau SW)

Time Apply 14 to 30 days before planting field corn at 2 oz/a.

Remarks Apply with preplant burndown herbicides such as glyphosate, glufosinate, or paraquat) in no till or minimum tillage fields.

Caution Do not irrigate between emergence and 2-leaf stage.

Site of action Group 14: protoporphyrinogen oxidase inhibitor

Chemical family Diphenylether

flufenacet + metribuzin (Axiom DF)

Rate 0.78 lb ai/a flufenacet + 0.19 lb ai/a metribuzin (23 oz Axiom DF)

Time Apply pre-emergence and activate with moisture prior to weed emergence.

Remarks Do not exceed 0.78 lb ai/a flufenacet, 0.19 lb ai/a metribuzin (23 oz Axiom DF) per season. If any crop treated with Axiom DF is lost, field corn may be planted immediately. DO NOT make a second application of Axiom DF.

Caution Do not apply flufenacet + metribuzin through any type of irrigation system, do not apply aerially, do not use flood irrigation to apply, activate, or incorporate flufenacet + metribuzin herbicide in the soil. Do not apply flufenacet + metribuzin in tank mixture when environmental conditions may favor drift to non-target sites.

Site of action (flufenacet) Group 15: inhibits very long chain fatty acid synthesis; (metribuzin); Group 5: PS II inhibitor

Chemical family oxyacetamide + triazinone

halosulfuron + thifensulfuron (PermitPLUS)

For preplant and postemergence residual in field corn

Rate 0.031 lb ai/a halosulfuron + 0.0036 lb ai/a thifensulfuron (0.75 oz/a)

Time When used alone, PermitPLUS can be applied over the top or with drop nozzles to 2- to 6-leaf corn (1 to 5 collars). PermitPLUS can be applied only once per season at a rate of 0.75 oz/a (0.031 lb/a halosulfuron + 0.0036 lb/a thifensulfuron). PermitPLUS can also be applied postemergence.

Remarks Following application to foliage, allow 30 days before grazing domestic livestock, harvesting forage, or harvesting silage. Apply PermitPLUS to field corn hybrids with Relative Maturity (RM) of 88 days or more, including "food grade" (yellow dent, hard endosperm), waxy, and high-oil corn.

Caution Do not irrigate between emergence and 2-leaf stage.

Site of action Group 2: Acetolactate synthase (ALS) inhibitor

Chemical family Sulfonylurea

mesotrione (Callisto)

Do not use on white popcorn

Rate 0.078 to 0.094 lb ai/a (2.5 to 3 fl oz/a)

Time Apply preemergence.

Remarks Controls several annual broadleaf weeds. If overhead moisture (0.25 inch) is not received within 7 to 10 days after application, rotary hoe to activate the herbicide. Will not control most grass weeds. May be tank mixed with preemergence grass herbicides to broaden activity. Do not mix with organophosphate (i.e. Lorsban) or carbamate insecticides due to crop injury concerns.

Caution Do not exceed 0.24 lb ai/a (7.7 oz/a product) per season. See label for crop rotation restrictions.

Site of action Group 27: inhibits 4-hydroxyphenylpyruvatedioxygenase (4-HPPD)

Chemical family Triketone

pendimethalin (Prowl H2O)

Rate 0.95 to 1.9 lb ai/a (2 to 4 pints/a Prowl H20)

Time Apply after planting but before crop or weeds emerge.

Remarks Rate depends on soil type and organic matter content. Plant in a seedbed that is firm and free of clods and trash. Plant at least 1.5 inches deep to ensure good seed coverage. See label for tank-mix combinations. Weed control is best when adequate rain or overhead irrigation is received within 7 days after application.

Caution Do not incorporate; serious corn injury can result. Make sure corn is planted 1.5 inches deep. Do not use on peat or muck soil.

Site of action Group 3: microtubule assembly inhibitor

Chemical family Dinitroaniline

pyroxasulfone (Zidua SC)

For corn grown for grain, processing, or silage, popcorn, and sweetcorn (grown for fresh, processing or seed)

Rate 1.3 to 3.4 oz ai/a (2.5 to 6.5 fl oz /a Zidua SC)

Time May be applied in a single application or in sequential applications. Apply as a single preplant surface application, preplant incorporated, or preemergence at 1.3 to 3.4 fl oz/a depending on soil texture (consult label for details). When applied as a residual component of a planned sequential (two pass program) use 0.91 to 3.4 oz ai/a depending on soil texture (consult label for details).

Remarks Zidua SC may be broadcast surface applied in the fall or winter to control winter annual weeds germinating in fall. Sequential preemergence or postemergence application can be made, but do not exceed the maximum cumulative rate allowed by soil type per season. Consult the label for preplant surface application (15 to 45 days before planting) and for preplant surface or preplant incorporated application (up to 14 days before planting). Sequential application program of Zidua SC (e.g. fall application followed by spring application or sequential applications in the spring), the maximum combined rate is 2.35 oz ai/a on coarse soils or 4.43 oz ai/a on all medium-to-fine soils per year.

Caution Corn seed must be planted a minimum 1 inch deep. Consult the label for tank mix partners. If a labeled crop treated with Zidua SC is lost to crop failure (because of environmental factors including drought, frost, hail, etc.), the crop may be replanted. However, do not repeat application of Zidua SC after crop failure. Consult the label for the interval between Zidua SC application and the planting of rotation crops. There is no preharvest interval for soybean grain, sunflower, or cotton. Consult label for detailed information and other crop rotation restrictions.

Site of action Group 15: Very long chain fatty acid synthesis inhibitor

Chemical family Chloroacetamide

pyroxasulfone + fluthiacet methyl (Anthem)

Rate 0.084 to 0.218 lb ai/a (5 to 13 oz/a)

Time Apply 15 to 45 days preplant through preemergence. See label for application timing, soil type, organic matter, and rate information.

Remarks Preplant, preplant incorporated, and early preemergence applications may be made up to 45 days prior to planting and up to crop emergence. Apply alone or in tank-mixture to broaden weed spectrum. Where emerged weeds are present at the time of application, use appropriate weed control measures to control emerged weeds. For early preplant applications in reduced-tillage systems, use the higher rate for soil type. Requires rainfall or irrigation to activate.

Caution Do not exceed a total of 16.3 oz/a of Anthem per season. See label for rotational restrictions. Preplant surface applications are not recommended on coarse soils where annual rainfall exceeds 40 inches. Do not harvest field corn for forage for 30 days after application. Do not harvest for grain for 70 days after application. Do not harvest sweet corn forage or ears until 40 days after application. Make only one preplant/preemergence application per season.

Site of action (pyroxasulfone) Group 15: inhibits long chain fatty acid synthesis; (fluthiacet methyl); Group 14 protoporphyrinogen oxidase inhibitor

Chemical family (pyroxasulfone) Chloroacetamide; (fluthiacet methyl) Imine

pyroxasulfone + fluthiacet methyl + atrazine (Anthem ATZ)

Rate 1.126 to 2.253 lb ai/a (32 to 64 oz/a)

Time Apply 15 to 45 days preplant through preemergence. See label for application timing, soil type, organic matter, and rate information.

Remarks Preplant, preplant incorporated, and early preemergence applications may be made up to 45 days prior to planting up to crop emergence. Apply alone or in tank-mixture to broaden weed spectrum. Where emerged weeds are present at the time of application, use appropriate weed control measures to control emerged weeds. For early preplant applications in reduced-tillage systems, use the higher rate for soil type. Requires rainfall or irrigation to activate.

Caution Restricted-use herbicide. Do not exceed a total of 39 oz/a of Anthem ATZ per season on coarse-textured soils or 70 oz/a on fine-textured soils. See label for rotational restrictions. Preplant surface applications are not recommended on coarse soils where annual rainfall exceeds 40 inches. Do not harvest field corn for forage for 60 days after application. Do not harvest for grain for 70 days after application. Do not harvest sweet corn forage or ears until 45 days after application. Make only one preplant/preemergence application per season.

Site of action (pyroxasulfone) Group 15: inhibits long chain fatty acid synthesis; (fluthiacet methyl) Group 14 protoporphyrinogen oxidase inhibitor; (atrazine) Group 5: photosystem II inhibitor

Chemical family (pyroxasulfone) Chloroacetamide; (fluthiacet methyl) Imine; (atrazine) Triazine

rimsulfuron (Resolve DF, Resolve SG, Pruvin, Bestow)

Field corn only

Rate 0.008 to 0.031 lb ai/a (0.5 to 2 oz/a)

Time Apply preplant or preemergence.

Remarks Check label for rates for each application timing. Apply to field corn hybrids with a relative maturity date of 77 days or more. If weeds are present at time of application, use an appropriate surfactant. Allow at least 4 weeks between preemergence and postemergence applications. Rain or sprinkler irrigation enhances control.

Caution Not all corn hybrids or Hi-Lysine hybrids have been tested for crop safety. Do not exceed 0.031 lb ai/a (2 oz/a product) per year. Consult label for re-cropping restrictions. Rimsulfuron may interact with some soil-applied organophosphate insecticides resulting in corn injury

Site of action Group 2: acetolactate synthase (ALS) inhibitor

Chemical family Sulfonylurea

saflufenacil (Sharpen)

Grain, silage, popcorn

Rate 0.044 to 0.067 lb ai/a (2 to 3.5 fl oz/a product depending on soil texture)

Time Apply early preplant surface (15 to 30 days before planting), preplant surface or incorporated (0 to 14 days before planting), and post-plant surface (before corn emergence).

Remarks Burndown broadleaf weed control with residual control dependent on rate. An adjuvant system is required for optimum broadleaf burndown activity such as methylated seed oil plus ammonium sulfate. PHI is 80 days. Tank mix with Outlook or other soil active herbicides to improve residual control.

Caution Do not apply after corn has emerged because corn will be severely injured.

Site of action Group 14 Protoporphyrinogen IX oxidase (PPO) inhibitor

Chemical family Pyrimidinedione

S-metolachlor (Dual II Magnum or Dual Magnum)

Rate 0.95 to 1.9 lb ai/a (1 to 2 pints/a Dual II Magnum (contains crop safener) or Dual Magnum or Moccasin 960 (contains no safener)

Time Apply either preplant incorporated or preemergence.

Remarks Use preplant incorporated if furrow irrigated and incorporate into the top 2 inches of soil before planting. Use lower rate on coarse soils, higher rate on fine soils. Preemergence treatment may be used when overhead moisture is expected and should be applied before weeds and corn emerge. May be combined with atrazine to better control broadleaf weeds. Dual II Magnum contains a safener to reduce injury potential to the crop.

Caution If crop treated only with S-metolachlor is lost, corn, soybeans, potatoes, safflower, and labeled pod crops can be replanted immediately. Small grains can be planted 4.5 months after application. Consult label for other crop rotation restrictions.

Site of action Group 15: inhibits very long chain fatty acid synthesis

Chemical family Chloroacetamide

S-metolachlor (Medal II EC)

Rate 1.27 to 1.9 lb ai/a (1.33 to 2 pints/a)

Time Apply either preplant surface, preplant incorporated, preemergence, post-emergence, or lay-by, using the appropriate rate specified on the label.

Remarks Rate is dependent on soil organic matter and application timing (see the label). A tillage operation may precede the application. A fall and/or a spring tillage may follow application, but do not exceed an incorporation depth greater than 2 to 3 Inches. Minimize furrow and ridge formation in the tillage operations. If a spring application is made, the total rate of the fall plus spring applications must not exceed the maximum total rate for corn, or Illegal residues may result.

Fall application for control or suppression of yellow nutsedge: For preemergent control or suppression of yellow nutsedge the following spring, apply 1.33 pints/a of Medal II EC in the fall after the harvest of the previous crop but before freeze-up.

Caution Apply no more than 1.33 pints/a in a single fall preplant application. Do not apply to frozen ground. If a fall application is made, the combined total amount applied in the fall plus spring must not exceed the maximum season S-metolachlor rate for corn (3.9 pints/a, depending on soil texture) or illegal residues may result. Do not graze or feed for age from treated areas for 30 days following application. If crop treated only with S-metolachlor is lost, consult the label for replant crops. Consult label for other crop rotation restrictions.

Site of action Group 15: inhibits very long chain fatty acid synthesis

Chemical family Chloroacetamide

S-metolachlor + atrazine (Bicep II Magnum FC)

Rate 2.9 to 3.55 lb ai/a (2.1 to 2.6 quarts/a Bicep II Magnum FC)

Time Apply either preplant, preemergence, or postemergence.

Remarks Use preplant, preemergence, or postemergence control of most annual grasses and broadleaf weeds In corn. May be tankmixed with other herbicides for weed control in conventional, minimum-till, and no-till corn. Tank mixtures are permitted only in those states where the tank mix partner is registered (see full label for details). When tank mixing or sequentially applying atrazine or products containing atrazine to corn, do not exceed an application rate of 2 lb ai/a of atrazine for any single application and the total pounds of atrazine applied must not exceed 2.5 lb ai/acre per year.

Caution Restricted use pesticide (ground and surface water concerns). For retail sale to and use only by certified applicators or persons under their direct supervision, and only for those uses covered by the certified applicator's certification Consult label for atrazine use restrictions. Bicep II Magnum contains atrazine and S-metolachlor as active ingredients. Check the label for restrictions on use on soils considered "highly erodible land" (as defined by the Natural Resource Conservation Service). Do not rotate to food or feed crops other than those listed on the label. In case of crop failure, corn or sorghum (milo) may be planted immediately. Do not apply a second application of Bicep II Magnum. Do not rotate to sugar beet, vegetables (including beans), and small grains the year after application.

Site of action (S-metolachlor) Group 15: inhibits very long chain fatty acid synthesis; (atrazine) Group 5: photosystem II inhibitor.

Chemical family (S-metolachlor) Chloroacetamide; (atrazine) Triazine

S-metolachlor + atrazine + bicyclopyrone + mesotrione (Acuron)

Rate 2.15 to 2.58 lb ai/a (2.5 to 3 quarts/a Acuron)

Time Apply either preemergence or post emergence.

Remarks Acuron is a combination of the herbicides atrazine, bicyclopyrone, mesotrione and S-metolachlor plus the safener benoxacor. Rate is dependent on soil organic matter. When tank mixing or sequentially applying atrazine or products containing atrazine with Acuron to corn, do not exceed an application rate of 2.0 lb active ingredient of atrazine per acre for any single application and the total pounds of atrazine applied (lb ai/a) must not exceed 2.5 lb active ingredient per acre per year. When applied according to directions and under normal growing conditions, Acuron will not harm the treated crop. During germination and early stages of growth, extended periods of unusually cold and wet or hot and dry weather, insect or plant disease attack, carryover pesticide residues, the use of certain soil applied systemic insecticides, or improperly placed fertilizers or soil insecticides, may weaken crop seedlings. Acuron used under these conditions could result in crop injury. Where reference is made to weeds partially controlled, partial control can either mean erratic control from good to poor or consistent control at a level below that generally considered acceptable for commercial weed control. Dry weather following preemergence application of Acuron or an Acuron tank mixture may reduce effectiveness. If possible, cultivate if weeds develop. Applying Acuron postemergence to corn that has received an at-plant application of Counter insecticide can result in severe corn injury. Temporary corn injury may occur if Acuron is applied to emerged corn where organophosphate insecticides other than Counter were applied at planting. Postemergence (emerged corn) applications of any organophosphate or carbamate insecticide within 7 days before or 7 days after a Acuron application may result in severe corn injury.

Caution Grazing Restriction: To avoid possible illegal residues, do not graze or feed forage from treated areas for 45 days following application. Pre-Harvest Interval (PHI): Corn (for grain, seed, or silage) may be treated up to 12 inches tall. Do not harvest forage within 60 days after application. Do not apply more than 3.0 quarts of Acuron per acre per growing year. Do not use aerial application to apply Acuron. Do not apply Acuron to sweet corn or yellow popcorn after the crop has emerged or severe crop injury may occur. Do not use Acuron on any crop other than corn (for grain, seed, or silage), sweet corn (preemergence applications only) or yellow popcorn (preemergence applications only). Do not use Acuron in the culture of white popcorn or ornamental (Indian) corn or injury may occur. Do not contaminate irrigation water used for crops or water used for domestic purposes. Thoroughly clean sprayer or other application device before using. Dispose of cleaning solution in a responsible manner. Do not use a sprayer or applicator contaminated with other materials, or crop damage or sprayer clogging of the application device may occur. If crop treated only with Acuron is lost, corn (field, seed, silage), sweetcorn, yellow popcorn, can be replanted immediately. Small grain cereals including wheat, barley and rye can be planted 4 months after application. Dry bean and potato can be planted 10 months and all other crops after 18 months. Consult label for complete crop rotation list.

Site of action (S-metolachlor) Group 15: inhibits very long chain fatty acid synthesis; (S-metolachlor) Group 5: photosystem II inhibitor; bicyclopyrone and mesotrione: Group 27: inhibits 4-hydroxyphenylpyruvatedioxygenase (4-HPPD).

Chemical family (S-metolachlor) Chloroacetamide; (atrazine) Triazine; (bicyclopyrone and mesotrione) Triketone

simazine (Princep 4L)

Rate 2.0 lb ai/a (2 quarts/a Simazine 4L)

Time Apply as a single preemergence application on soils that are not highly erodible (consult label for details). Total simazine applied may not exceed 2.5 lb ai/a per calendar year.

Remarks If the soil is highly erodible and covered with <30% plant residues, apply a maximum of 1.6 lb ai/a as a single application. Pre-grazing/pre-harvest interval for corn is 60 days. For preemergence application must be made before weeds and corn emergence as specified on the label. Preplant application should be broadcast in the spring after plowing at the specified rate on the label depending on plant residue cover. Apply before, during, or after final seedbed preparation. If soil is tilled or worked after application, avoid deep incorporation. Best results will be obtained when simazine is applied within 2 weeks before planting. Under dry weather conditions, preplant applications may give better weed control that preemergence. If weeds develop, particularly under relatively dry conditions, a shallow cultivation will generally result in better weed control. Simazine may be tank mixed with other herbicides as specified on the label.

Caution Do not plant any crop except corn until the following year, or injury may occur. Following harvest, plow and thoroughly till the soil in fall or spring to minimize possible injury to spring-seeded rotational crops, regardless of the rate used. Do not plant sugar beets, tobacco, vegetable (including dry beans), spring seeded small grain, or small-seeded legumes and grasses the year following application, or injury may occur. Consult label for detailed information and other crop rotation restrictions.

Site of action Group 5: inhibits photosystem II

Chemical family Triazine