Table 2.2-13. Postemergence herbicides for corn.
- The following treatments are applied after corn emergence to control established weeds. See specific product label to determine correct rate for soil type and weed species found in individual fields.
| Herbicide¹ | Product/A | lb ai/A | Remarks |
|---|---|---|---|
| 2,4-D amine 4S | 0.5–1.0 pt | 0.2–0.5 | Use from time corn emerges until approximately 36 inches. Risk of 2,4-D injury increases as corn increases in size. Use 0.5 pt rate with drop nozzles after corn exceeds 8 inches in height. Corn is most susceptible to injury when growing rapidly. Adjust sprayer to minimize drift in order to prevent injury to nontarget plants. |
| Accent 75DF (nicosulfuron) | 0.67 oz | 0.031 | Apply when shattercane is 4–12 inches, rhizome johnsongrass 8–18 inches, foxtail 2–4 inches, and quackgrass 4–10 inchestall. Apply to corn broadcast or directed up to 24 inches tall or directed up to 36 inches tall. Include appropriate adjuvant in spray tank (see Table 2.2-16). Accent may be tank-mixed with certain herbicides. (Celebrity Plus is a premix of Accent + Distinct). Do not tank-mix with Basagran, Bladex, Laddok, or 2,4-D. Do not use Counter 15 G. Do not use Counter 20 CR in-furrow or over-the-row at cultivation; may be banded, but may cause injury, especially on soils with less than 4% organic matter. Less restrictive for IR hybrids (not IT). The use of Dyfonate, Lorsban, Thimet may result in temporary injury. There are no precautions for Non-OP insecticides. To prevent herbicide resistance, avoid repeated annual applications of soil-persistent ALS. See “Herbicide Resistance Management” in Part 2, Section 1 for more information. |
| Aim 1.9EW or 2EC (carfentrazone) | 0.5–1.0 fl oz | 0.008–0.016 | Apply to corn up to 8-leaf collar stage and when weeds generally are 1–4 inches tall. Include a nonionic surfactant (2 pt/100 gal). Tank-mix with other herbicides to increase weed control spectrum. Do not combine with EC formulation herbicides or with COC when tank-mixing. Rage D-Tech is a premix of Aim plus 2,4-D ester. |
| Atrazine 4L | 1–2 qt | 1–2 | Apply before weeds are 1.5 inches tall and before corn reaches 12 inches in height. Add 1 qt crop oil concentrate/A to spray solution. Do not include oil if corn is under stress from prolonged cold, wet weather or other factors. See atrazine use restrictions at the end of Table 2.2-7, and refer to current label for additional information. (Restricted-use pesticide and water quality advisory) |
| Basgran 4S (bentazon) | 1.5–2.0 pt | 0.75–1.0 | Apply when weeds are small and actively growing. Split treatments may be required for yellow nutsedge and Canada thistle. Include the appropriate adjuvant in the spray tank (see Table 2.2-16). Basagran poses less threat to off-target plants from drift than 2,4-D or Banvel. Basagran is weak on pigweed. |
| Beacon 75DF (primisulfuron) | 0.38–0.76 oz | 0.018–0.036 | Apply when shattercane is 4–12 inches, rhizome johnsongrass is 8–16 inches, quackgrass is 4–8 inches, fall panicum is less than 2 inches, and broadleaved weeds are less than 4–9 inches tall depending on species. Apply to corn between 4 and 20 inches in height. A second application may be made before tassel emergence (0.57 + 0.19 or 0.38 + 0.38 oz). Include the appropriate adjuvant in the spray tank (see Table 2.2-16). Beacon may be applied at a reduced rate (0.38 oz) alone or in combination with Atrazine, Accent, Banvel, Clarity, Buctril, or 2,4-D for control of certain broadleaves or grasses. (NorthStar is a prepackaged product containing Beacon + dicamba.) May be applied with drop nozzles if corn is too tall. Do not use Counter 15 G. Do not use Counter 20 CR in-furrow or over-the-row at cultivation; may be banded, but may cause injury. Do not make foliar or soil applications of an OP insecticide within 10 days before or 7 days after Beacon application. Less restrictive for IR or IMR hybrids (not IT). Dyfonate, Lorsban, Thimet, other OP’s may result in temporary injury. There are no precautions for non-OP insecticides.To prevent herbicide resistance, avoid repeated annual applications of soil-persistent ALS herbicides. See “Herbicide Resistance Management” in Part 2, Section 1 for more information. |
| Buctril 2E (bromoxynil) | 1.0–1.5 pt | 0.25–0.375 | Apply to small actively growing weeds. Buctril poses less threat to off-target plants from drift than 2,4-D or Clarity/Banvel. Buctril is weak on pigweed. |
| Callisto 4SC (mesotrione) | 3 fl oz | 0.094 | Callisto can be applied postemergence at 3 fl oz/A to corn up to 30 inches tall (8-leaf stage). Always include crop oil concentrate and UAN or AMS in the spray mixture. Do not use methylated seed oil (MSO). To broaden broadleaf weed control include atrazine (0.25–0.5 lb) in the mixture. Do not apply more than a total of 7.7 oz/A of Callisto/A/season. Do not apply Callisto postemergence in a tank mix with emulsifiable concentrate grass herbicides. Do not apply Callisto postemergence: 1) if the crop was previously treated with Counter or Lorsban insecticide, 2) with any OP or carbamate insecticide, 3) seven days before or after an OP or carbamate insecticide was applied, or 4) if Lumax or Camix was applied earlier that season. Small grains may be planted 4 months after application. Corn, soybeans, and sorghum can be planted the year after application, 10-month restriction for alfalfa and 18-month restriction for clover. |
| Clarity 4S (dicamba) or Banvel 4S |
8–16 fl oz or 0.5–1.0 pt |
0.25–0.5 | May apply Clarity or Banvel up to 1 pint before corn is 8 inches tall (5-leaf stage). Use 0.5 pint on corn between 8 and 36 inches. Take precautions to prevent drift of dicamba off the target site. Early postemergence applications are preferable for lambsquarters control. |
| Harmony SG 50WDG (thifensulfuron) | 0.125 oz (1/8 oz) | 0.063 | Harmony SG can be applied to 2–6 leaf corn (1–4 collars, up to 12 inches tall) at a rate of 1/12 oz/A. Harmony SG can be used in a tank-mix to control velvetleaf, pigweed, smartweed, wild mustard, and lambsquarters (including triazine-resistant species). Include the necessary adjuvants in the spray solution. Do not apply Harmony SG to normal or IT corn previously treated with Counter 15G or 20CR, Thimet, Dyfonate, Lorsban, or other OP insecticides, otherwise crop injury will result. No insecticide herbicide restriction with IR corn hybrids. There are no precautions for Fortress or Force insecticides. Harmony SG is an ALS inhibitor herbicide. To prevent herbicide resistance, see “Herbicide Resistance Management” in Part 2, Section 1 for more information. |
| Ignite 280 2.34L (formerly known as Liberty) (glufosinate) | 22–29 oz | 0.40–0.53 | Ignite controls most annual grasses and broadleaves. Apply over-the-top to glufosinate-resistant (e.g. LibertyLink) corn only. Do not use post if Ignite was used prior to planting. Two postemergence applications of Ignite can be applied at least 10 to 14 days apart. Broadcast applications may be made from corn emergence until corn is in the V-5 stage of growth, whichever comes first. For best results, apply 22 to 29 fl oz of Ignite when weeds are 2 to 6 inches tall. Do not apply more than 44 fl oz/A/growing season. Ignite herbicide should generally follow a soil residual herbicide program and/or be tank-mixed with an appropriate postemergence product to broaden the spectrum of control. Applications should be made between dawn and 2 hours before sunset to avoid the possibility of reduced lambsquarters or velvetleaf control. Weed control can be reduced if application is made when heavy dew, fog, or mist are present or when weeds are under environmental stress. Ignite provides no soil residual activity. See Table 2.2-16 for adjuvant information. Include ammonium sulfate (AMS) at 3 lb/A (17 lbs/100 gal) but a lower rate is recommended if temperatures exceed 85 degrees (8.5 lbs/100 gal) to reduce risk of leaf burn. Do not add any surfactants or crop oils. |
| Impact 2.8SC (topramezone) | 0.75 fl oz | 0.0164 | Impact is similar to Callisto, but has more annual grass activity. Impact can be applied postemergence at 0.75 fl oz/A to corn up to 45 days prior to corn harvest (use drop nozzles when necessary). Always include methylated seed oil (MSO) or crop oil concentrate (COC) and UAN or AMS in the spray mixture. To broaden broadleaf weed control include atrazine (0.25–1.0 lb/A) in the mixture. Do not apply more than 0.75 fl oz/A/seson or tank mix or apply in sequence with products containing isoxaflutole (Balance, Radius) or mesotrione (Callisto, Lumax, Lexar). Impact may be used after or in combination with all soil or foliar-applied insecticides registered for use in corn. Impact will control/suppress crabgrass, foxtails, and other grass species but is weak on fall panicum. Corn can be planted anytime after Impact application, 3 month restriction for small grains, 9-month restriction for alfalfa, potato, and sorghum and 18 months for other crops. |
| Laudis 3.5SC (tembotrione) | 3 fl oz | 0.082 | For best results apply Laudis at 3 fl oz/A when weeds are small (i.e., 1 to 3 inches tall). Methylated seed oil (MSO) or crop oil concentrate (COC) adjuvants are recomended by manufacturer. In addition, nitrogen fertilizer is required (UAN or AMS). Tank-mix with 0.25 to 1 lb ai/A of atrazine for improved control and to broaden the sprectrum of control. Local university data supports at least 0.5 lb ai/A of atrazine. Do not apply the tank mixture of Laudis and atrazine to corn greater than 12 inches tall. Laudis can be tank-mixed with other herbicides to improve weed control spectrum. Laudis will control/suppress crabgrass, foxtails, and other grass species, but it will not control fall panicum. Do not make more than two applications of Laudis in a growing season. Be cautious of crop rotation restrictions. See label for additional use details. |
| Option 35WDG (foramsulfuron) | 1.5–1.75 oz | 0.033–0.038 | Broadcast application of Option can be made from corn emergence to 16 inches tall (V5 growth stage); use drop nozzles when corn is 16–36 inches tall. The typical use rate is 1.5 oz/A. Include methylated seed oil (MSO) plus nitrogen fertilizer (UAN or AMS) in the spray mixture. (The use of nonionic surfactant or crop oil concentrate will result in unacceptable weed control.) Do not use Option in the same season as Counter 15G or 20CR, Dyfonate, or Thimet. There are no precautions with other insecticides, including Regent, Aztec, Force, and Lorsban. To prevent herbicide resistance, avoid repeated annual applications of soil-persistent ALS herbicides. See “Herbicide Resistance Management” in Part 2, Section 1 for more information. See Table 2.2-17 for recrop restrictions. |
| Permit 75WG (halosulfuron) | 0.67–1.33 oz | 0.032–0.063 | Apply to corn from spike through layby (last cultivation). The 0.67 oz rate is the standard rate for annual weed control. Permit is excellent on yellow nutsedge, but is weak on common lambsquarters. Tank-mix with products such as Clarity/Banvel or 2,4-D to increase the weed control spectrum. Yukon is a prepackaged product containing Permit + dicamba. Permit has no insecticide use restrictions. To prevent herbicide resistance, avoid repeated annual applications of soil-persistent ALS herbicides. See “Herbicide Resistance Management” in Part 2, Section 1 for more information. |
| Resolve 25DF (rimsulfuron) | 0.5–2.0 | 0.0078–0.03 | Resolve contains the single active ingredient rimsulfuron. Resolve can be applied pre or post in corn at 0.5–2 oz/A. Use the higher rate when applying as a tank-mix partner in pre program. The typical use rate for post applications is 1 oz/A, plus the necessary adjuvants. Resolve alone will control small seedling weeds, grasses less than 2 inches and broadleaves less than 3 inches. Resolve will control crabgrass less than ½ inch tall. Resolve can be tank-mixed with glyphosate to provide residual control of broadleaf and grass weed species emerging after the application. Resolve may be tank-mixed with full or reduced rates of other corn herbicides as well. Do not apply Resolve to corn under stress due to crop injury. Refer to the Resolve label for all restrictions concerning increased injury when tank-mixed with organo-phosphate insecticides (Counter, Lorsban, or Thimet). Do not tank-mix with Basgran or Laddock due to crop injury concern. Apply Resolve up to 12 inch tall corn or before the appearance of 6 or more collars, whichever is more restrictive. Resolve must be applied with a nonionic surfactant (NIS) and nitrogen fertilizer. Crop oil concentrate (COC) may be used in place of nonionic surfactant. When applying Resolve in tank-mixture with a glyphosate product that contains a “built-in” adjuvant system, the Resolve label does not recommend the use of extra adjuvants. To prevent herbicide resistance, avoid repeated annual applications of soil persistant ALS herbicides. See “Herbicide Resistance Management” in Part 2, Section 1 for more information. |
| Resource 0.86EC (flumiclorac) | 4–6 oz | 0.027–0.04 | Apply to corn from 2-leaf to 10-leaf stage. Good on velvetleaf up to 30 inches tall. Tank-mix with other products such as Banvel or atrazine to increase the weed control spectrum. |
| Roundup WeatherMax 4.5S
(glyphosate) or Touchdown Total 4S (glyphosate) or Duramax 4S or other glyphosate products |
22 fl oz or 24 fl oz or 24 fl oz see Table 2.2-1a |
0.75 lb ae or 0.75 lb ae or 0.75 lb ae |
Apply over-the-top to Roundup Ready corn hybrids only. Apply from corn emergence through the V8 stage (or 30 inches) in a 10–20 GPA spray solution. Do not apply more than 22 oz/A (or 0.75 lb ae/A) Roundup WeatherMax in a single in-crop application or more than 44 oz/A/season (or 2 lb ai). (*Note: Adjust application rate if using glyphosate 3S or Touchdown; for example: 22 fl oz WeatherMax = 1 qt glyphosate/Touchdown. Refer to current product label for other use restrictions.) For corn grain and silage corn, two in-crop applications of Roundup can be made; allow 10 days between applications. For best results, apply a pre residual herbicide (e.g., Harness, Harness Xtra, Bicep, Fultime, Guardsman, etc.) followed by glyphosate when weeds are 4–6 inches tall. Reduced rates of glyphosate are possible if susceptible annual weeds are small and actively growing. Early postemergence programs that include glyphosate plus a residual herbicide also are an option, but may not be as consistent as the preemergence followed by the postemergence program. Be cautious of corn height restrictions for residual herbicides. Roundup WeatherMax does not require additional adjuvants in the spray tank under most conditions. Do not harvest silage for 50 days or grain for 7 days after last application. (Refer to Table 2.2-1a for various glyphosate products and see specific product label for additional application information and restrictions.) |
| Sencor 75DF (metribuzin) | 2 oz | 0.094 | Sencor may be applied postemergence at the 2 oz rate in tank-mix combination with atrazine, Banvel, Clarity, Basagran, Laddok, Buctril, Marksman, and 2,4-D for improved control of certain broadleaf weeds (e.g., velvetleaf). Observe precautions and limitations of tank-mix partners. (Water quality advisory) |
| Stinger 3S (clopryalid) | 0.25–0.66 pt | 0.093–0.25 | Apply to corn up to 24 inches tall. Use 0.25–0.5 pt/A for ragweed, cocklebur and Jerusalem artichoke and 0.33–0.66 pt/A for Canada thistle. Delay planting soybeans or canola for 12 months following Stinger application. (Water quality advisory) |
| Mixtures | |||
| Basis 75DF (rimsulfuron + thifensulfuron) | 0.33 oz | 0.015 | Basis is a mixture of rimsulfuron and thifensulfuron (Harmony GT). Apply to corn from spike stage through 2 collars (about 6 inches tall). Do not apply to corn having 3 fully emerged collars or to corn over 6 inches tall. Basis controls some small annual grasses and broadleaves. Basis must include an adjuvant including an ammonium nitrogen fertilizer. Do not tank-mix with Basagran, Laddok, Bladex, or other ALS inhibiting herbicides. Do not use Counter 15 G. Counter 20 CR and Thimet may cause unacceptable crop injury, especially on soils with less than 4% organic matter. Less restrictive for IR hybrids (not IT). Dyfonate, Lorsban and other OP’s may result in temporary injury. There are no precautions for Force and Fortress. To prevent herbicide resistance, avoid repeated annual applications of soil persistent ALS herbicides. See “Herbicide Resistance Management” in Part 2, Section 1 for more information. |
| Buctril + atrazine 3L (bromoxynil + atrazine) | 1.5–3 pt | 0.56–1.12 | Consider previous atrazine applications and do not exceed 2.5 lb (qt)/A/year. Buctril + atrazine contains a 1:2 ratio of bromoxynil to atrazine. Apply up to 12-inch-tall corn. Surfactants or crop oil may be added to the spray tank, but the risk of crop injury increases. See atrazine restrictions at the end of Table 2.2-7. (Restricted-use pesticide and water quality advisory) |
| Celebrity Plus 70DF (nicosulfuron + dicamba + diflufenzopyr) | 4.7 oz | 0.21 | Celebrity Plus is a premix of Accent + Distinct. Apply 4.7 oz/A Celebrity Plus to corn 4 to 24 inches tall. Include a nonionic surfactant at 1–2 qt/100 gallons spray solution plus 1–2 qt/A of liquid nitrogen solution (UAN) or 1–2 lb/A of ammonium sulfate (AMS). Do not apply more than 9.4 oz/A per season. Do not use where Counter was applied in-furrow. Refer to product label for additional precautions. (Water quality advisory) |
| Curtail 2.38L (clopyralid + 2,4-D) | 2 pt | 0.6 | Curtail contains clopyralid (Stinger) and 2,4-D. Apply to corn less than 8 inches tall (V4). For increased control of Canada thistle, tank-mix Curtail with Stinger (2–6 fl oz). |
| Distinct 70DF (dicamba + diflufenzopyr) | 4–6 oz | 0.175–0.263 | Distinct contains dicamba (Clarity) plus another plant growth regulator (diflufenzopyr). Apply Distinct at 6 oz/A to 4- to 10-inch-tall corn. Apply 4 oz/A to 10–24-inch-tall corn (24–36 inches with drop nozzles). Do not exceed a total of 10 oz/A per season. Include a nonionic surfactant at 1 qt plus 5 qt of UAN (28–34% nitrogen) per 100 gallons of water. Distinct is effective on many broadleaf weeds. Do not tank-mix with products that contain 2,4-D, dicamba, or clopyralid, nor with Poast or Poast Plus. Refer to product label for additional precautions. (Water quality advisory) |
| Equip 32 WDG (formasulfuron + iodosulfuron) | 1.5 oz | 0.03 | Broadcast application of Equip can be made from corn emergence to 16 inches tall (V5 growth stage); use drop nozzles when corn is 16–36 inches tall. The typical use rate is 1.5 oz/A. Include methylated seed oil (MSO) plus nitrogen fertilizer (UAN or AMS) in the spray mixture. (The use of nonionic surfactant or crop oil concentrate will result in unacceptable weed control.) Do not use Equip in the same season as Counter 15G or 20CR, Dyfonate, or Thimet. There are no precautions with other insecticides, including Regent, Aztec, Force, and Lorsban. To prevent herbicide resistance, avoid repeated annual applications of soil-persistent ALS herbicides. See “Herbicide Resistance Management” in Part 2, Section 1 for more information. See Table 2.2-17 for recrop restrictions. |
| Halex GT 4.39EC (s-metolachlor+ mesotrione + glyphosate) | 3.6–4.0 pt | 1.98–2.2 | Halex GT contains s-metolachlor (Dual Magnum) + mesotrione (Callisto) + glyphosate (Touchdown HiTech) and can only be applied to glyphosate-resistant (RR) corn hybrids from emergence to 30 inches tall (8-leaf stage). For best results, apply to weeds before they are 4 inches tall. Include NIS and AMS in the spray mixture. Atrazine can be tank-mixed with Halex GT. Do not apply another HPPD-inhibitor herbicide (Callisto, Impact, Laudis) postemergence in the same season. Halex GT is not recommended for use as a preplant or preapplication. Halex GT can be used in a planned pre followed by post herbicide program. Use caution if applying OP or carbamate insecticides 7 days before or after Halex GT application. See label for additional use restrictions. |
| Hornet 78.5WDG (flumetsulam + clopyralid) | 2–4 oz | 0.086–0.17 | Hornet is a mixture of flumetsulam (Python) + clopyralid (Stinger). The 2–4 oz rate range is a reduced rate for post-emergence use. Apply to corn up to 20 inches tall (V6 corn stage) when broadleaf weeds are 1 to 8 inches in height depending on use rate. Include the necessary adjuvants in the mixture (Table 2.2-16). Do not use Hornet if Counter insecticide was applied. Other organophosphate insecticides such as Lorsban, Thimet, Aztec, or Dyfonate may cause temporary crop injury. Do not tank-mix with foliar postemergence organophosphate insecticides. Refer to product label for use restrictions. To prevent herbicide resistance, avoid repeated annual applications of soil persistent ALS herbicides. See “Herbicide Resistance Management” in Part 2, Section 1 for more information. See Table 2.2-17 for recrop restrictions. (Water quality advisory) |
| Laddok S-12 5L (bentazon + atrazine) | 1.3–2.3 pt | 0.82–1.45 | Consider previous atrazine applications and do not exceed 2.5 lb (qt)/A/year. Laddok S-12 contains a 1:1 ratio of bentazon to atrazine (2.5 + 2.5 lb/gal). Apply up to 12-inch-tall corn. Include the appropriate adjuvant in the spray tank (see Table 2.2-16). Use crop oil concentrate for Canada thistle or yellow nutsedge. See atrazine restrictions at the end of Table 2.2-7. (Restricted-use pesticide and water quality advisory) |
| Lightning 70DG (imazethapyr + imazapyr) | 1.28 oz | 0.9 oz | Lightning is a mixture of imazethapyr (Pursuit) + imazapyr (Arsenal) for postemergence control of annual grasses and broadleaves in IMI-corn. Apply only to IMI-corn, also known as Clearfield or CL hybrids. Apply Lightning when weeds are 4 inches or less and to corn that is generally less than 20 inches tall. Include an appropriate adjuvant with Lightning (Table 2.2-16) and refer to Table 2.2-17 for rotational crop restrictions. Lightning contains two relatively persistent ALS-type herbicides. To prevent herbicide resistance, avoid repeated annual applications of soil persistent ALS herbicides. See “Herbicide Resistance Management” in Part 2, Section 1 for more information. (Water quality advisory) |
| Marksman 3.2L (dicamba + atrazine) | 2–3.5 pt | 0.8–1.4 | Consider previous atrazine applications and do not exceed 2.5 lb (qt)/A/year. Marksman contains 1.1 plus 2.1 lb of dicamba and atrazine, respectively, per gal. Apply Marksman up to the five-leaf stage of corn. Use 3.5 pt/A on medium textured soils or 2 pt/A on coarse-textured soils. Corn tolerance is greatest to Marksman at the spike stage of growth. Be cautious of drift from Marksman. See atrazine restrictions at the end of Table 2.2-7 for additional information. (Restricted-use pesticide and water quality advisory) |
| Northstar 47.4WDG (primisulfuron + dicamba) | 5 oz | 0.148 | NorthStar is a premix of primisulfuron (Beacon) plus the sodium salt of dicamba. NorthStar can be broadcast at 5 oz/A to corn 4 to 20 inches tall. Apply on a directed spray if corn is 20 to 36 inches tall. Include necessary adjuvants in the spray solution (Table 2.2-16). Do not apply if Counter was used. Do not make a foliar post or soil application of any OP insecticide within 10 days before or 7 days after NorthStar application. To prevent herbicide resistance, avoid repeated annual applications of soil persistent ALS herbicides. See “Herbicide Resistance Management” in Part 2, Section 1 for more information. |
| Ready Master ATZ 4L (glyphosate + atrazine) | 1.5–2.0 qt | 1.5–2.0 | Apply over-the-top to Roundup Ready corn hybrids only. Ready Master ATZ contains Roundup and atrazine. Apply this product postemergence from corn emergence until corn reaches 12 inches tall and when weeds are 2–4 inches tall. A single in-crop application must not exceed 2 qt/A. May be tank-mixed with certain herbicides to increase weed control spectrum and residual activity. See atrazine restrictions at the end of Table 2.2-7. (Restricted-use pesticide and water quality advisory) |
| Require Q 54.37WDG (rimsulfuron + dicamba + safener) | 4 oz | 0.13 | Apply Require Q at 4 oz/A after corn has reached 4 inches in height. Do not apply to corn taller than 20 inches in height. Applications made after weed emergence will provide contact control of labeled weeds and limited residual control of later emergence. For controll of emerged weeds, include a nonionic surfactant and an ammonium nitrogen fertilizer. If applied in combination with a glyphosate of glufosinate herbicide that contains a built-in adjuvant system, no additional surfactant needs to be added. Resolve Q may be tank-mixed with glyphosate or glufosinate herbicides if applications are made to corn hybrids containing appropriate herbicide tolerance genes, and can be tank-mixed with full or reduced rates of other products registered for use in corn. Crop oil concentrate can be used in place of nonionic surfactant for burndown applications of Require Q. Require Q may be tank-mixed with full or reduced rates of preemergence grass and broadleaf herbicides to provide added residual activity. Require Q may negatively interact with certain OP insecticides, see label for specific details. To prevent herbicide resistance, avoid repeated applications of soil-persistant ALS herbicides. See “Herbicide Resistance Management” in Part 2, Section 1 for more information. See Table 2.2-17 for recrop restrictions. |
| Resolve Q 22.4WDG (rimsulfuron + thifensulfuron + safener) | 1.25 oz | 0.0175 | Do not confuse Resolve with Resolve Q. Resolve Q contains rimsulfuron (Resolve) plus thifensulfuron (Harmony SG and a corn safener. Apply 1.25 oz/A postemergence to corn up to 20 inches tall. Applications made after weed emergence will provide contact control of labeled weeds and limited residual control of later emergence. For control of emerged weeds, include a nonionic surfactant and an ammonium nitrogen fertilizer. If applied in combination with a glyphosate or glufosinate herbicide that contains built-in adjuvant system, no additional surfactant need to be added. Resolve Q may be tank mixed with glyphosate or glufosinate herbicides if applications are made to corn hybrids containing appropriate herbicide tolerance genes, and can be tank-mixed with full or reduced rates of other products registered for use in corn. Do not tank-mix Resolve Q with Basagran or Laddock. Resolve Q may be tank-mixed with full or reduced rates of preemergence grass and broadleaf herbicides to provide added residual activity. Resolve Q may negatively interact with certain OP insecticides, see label for specific details. To prevent herbicide resistance, avoid repeated annual applications of soil-persistent ALS herbicides. See “Herbicide Resistance Management” in Part 2, Section 1 for more information. See Table 2.2-17 for recrop restrictions. |
| Shotgun 3.25L (atrazine + 2,4-D) | 2 pt | 0.81 | The 2-pint rate contains 0.56 lb atrazine + 0.25 lb 2,4-D. Apply over the top broadcast from spike to 4-leaf stage of corn (8 inches tall). Treated crop may be brittle and subject to breaking by wind or cultivation, especially in the two weeks following application. See atrazine restrictions at the end of Table 2.2-7. (Restricted-use pesticide and water quality advisory) |
| Spirit 57WG (prosulfuron + primisulfuron) | 1 oz | 0.036 | Spirit is similar to Exceed but is a 3:1 mixture of primisulfuron (Beacon) and prosulfuron (Peak). Soybeans may be planted 10 months after a Spirit application. Apply to corn between 4 and 24 inches in height (directed after 20 inches) when broadleaf weeds are small and actively growing. May be tank-mixed with certain herbicides to increase weed control spectrum. Include the appropriate adjuvant with all Spirit applications (Table 2.2-16). Do not use Counter 15 G. Do not use Counter 20 CR in-furrow or over-the-row at cultivation; may be banded, but may cause injury. Do not make foliar or soil applications of an OP insecticide within 10 days before or 7 days after Exceed application. Less restrictive for IR or IMR hybrids (not IT). Dyfonate, Lorsban, Thimet, and other OP’s may result in temporary injury. There are no precautions for non-OP insecticides. To prevent herbicide resistance, avoid repeated annual applications of soil-persistent ALS herbicides. See “Herbicide Resistance Management” in Part 2, Section 1 for more information. See Table 2.2-17 for recrop restrictions. |
| Steadfast 75DF (nicosulfuron + rimsulfuron) | 0.75 oz | 0.56 oz | Steadfast is similar to Basis Gold but does not contain atrazine, and has a 2:1 ratio of nicosulfuron to rimsulfuron. Apply Steadfast at 0.75 oz/A to corn up to 20 inches tall (7 collars) and while weeds are young and actively growing. Always include the necessary adjuvants in the spring mixture. Steadfast can be tank-mixed to improve control and increase weed spectrum. Refer to product label for additional use restrictions. To prevent herbicide resistance, avoid repeated annual applications of soil-persistent ALS herbicides. See “Herbicide Resistance Management” in Part 2, Section 1 for more information. See Table 2.2-17 for recrop restrictions. |
| Steadfast ATZ 89.3WDG (nicosulfuron + rimsulfuron + atrazine) | 14 oz | 0.78 | Steadfast ATZ is a mixture of atrazine, Accent, and rimsulfuron. (Steadfast 75DF is similar to Steadfast ATZ but does not contain atrazine. Refer to product label for more information.) Apply to corn up to 12 inches tall. Steadfast ATZ controls several annual grasses and broadleaf weeds. Include an adjuvant (Table 2.2-16) in the spray mixture. Steadfast ATZ should not be applied to corn with a relative maturity rating of less than 77 days. Do not use Counter 15G or 20G because unacceptable crop injury may be caused, especially on soils with less than 4% organic matter. Less restrictive for IR hybrids (not IT). Dyfonate, Lorsban, and Thimet may result in temporary injury. There are no precautions for non-OP insecticides. To prevent herbicide resistance, avoid repeated annual applications of soil-persistant ALS-herbicides. See “Herbicide Resistance Management” in Part 2, Section 1 for more information. See Table 2.2-17 for recrop restrictions. (Restricted-use pesticide and water quality advisory) |
| Stout 72.5WDG (nicosulfuron + thifensulfuron) | 0.5–0.75 oz | 0.023–0.034 | Stout contains nicosulfuron (Accent) and thifensulfuron (Harmony SG). The typical use rate for Stout is 0.75 oz/A and must include a crop oil concentrate (COC) on a nonionic surfactant (NIS) is the spray mixture as well as a nitrogen fertilzer (UAN or AMS). Stout can be applied up to 16 inch tall corn with less than 6 collars, whichever is more restrictive. Stout will not control crabgrass species. Do not tank-mix Stout with Basagran or Laddok due to crop safety concerns. Do not tank-mix with 2,4-D due to reduced grass control. Refer to Stout label for restrictions regarding OP insecticides such as Counter, Lorsban, Malathion, Thimet. Do not tank-mix with other ALS-inhibitor herbicides unless stated on herbicide label. Refer to product label for additional use restrictions. To prevent herbicide resistance, avoid repeated annual applications of soil-persistant ALS herbicides. See “Herbicide Resistance Management” in Part 2, Section 1 for more information. See Table 2.2-17 for recrop restictions. |
| SureStart 4.25SE (acetohlor + flumetsulam + clopyralid) | 1.5–2 pt | 0.8–1.06 | SureStart can be applied up to the early post stage (11-inch tall corn) and is intended to be used with Roundup Ready or Liberty Link field or silage corn hybrids. When applied pre, it is designed to provide early season control of common annual grasses and broadleaf weeds to allow better timing of the in-crop application of glyphosate or glufosinate. The use rate on medium-texture soils ranges from 1.5 to 1.75 pints/A. SureStart does not contain atrazine, so it provides a nonatrazine alternative for triazine-sensitive areas. However, atrazine and other herbicides can be tank-mixed with SureStart to broaden the weed control spectrum. SureStart can be tank-mixed with glyphosate (in Roundup Ready corn) or glufosinate (Liberty Link corn) to provide residual weed control. Applications should be made to weeds 2 inches or less in height. Make sure to plant corn 1½ inches deep and be cautious of interactions with certain OP insecticides that may cause crop injury. See label for additional details. |
| Yukon 67.5WDG (halosulfuron + dicamba) | 4–8 oz | 0.17–0.34 | Yukon is a premix of halosulfuron (Permit) plus the sodium salt of dicamba. Yukon can be applied at 4–8 oz/A to corn from spike to 36 inches tall; use drop nozzles when necessary. (The 4 oz/A Yukon rate equals 0.67 oz/A Permit plus 4 fl oz/A Clarity.) Include necessary adjuvants in the spray solution (Table 2.2-16). Yukon has no insecticide use restrictions. To prevent herbicide resistance, avoid repeated annual applications of soil-persistent ALS herbicides. See “Herbicide Resistance Management” in Part 2, Section 1 for more information. See Table 2.2-17 for recrop restrictions. |
| Harvest aid applications | |||
| 2,4-D LV4 | 1–2 pt | 0.5–1.0 | Apply 1–2 pt/A after the hard dough or dent stage to suppress large weeds that may interfere with harvest and to decrease production of weed seeds. Do not forage or feed corn fodder for 7 days after application. |
| Glyphosate (preharvest aid only) | see Table 2.2-1a | up to 0.75 lb ae | Glyphosate products are labeled for preharvest applications in corn. They can be applied from a week or more prior to harvest. Apply when grain has 35% or less moisture and after maximum kernel fill is complete and corn is physiologically mature. Do not apply to corn for seed. Refer to product label for application restrictions. |
| Gramoxone Inteon 2S (paraquat) (preharvest aid only) | 1.2–2.2 pt | 0.3–0.5 | Apply after corn is mature and black layer has formed. Make application at least 7 days before harvest. Use 0.8–1.3 pt/A in most cases as a harvest aid, otherwise the 1.5 pt/A rate can be used to desiccate mature broadleaves and grasses over 18 inches tall. Include a nonionic surfactant (1 qt/100 gal) in the spray solution. |
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Atrazine Use Restrictions
Preplant or Preemergence
On highly erodible soils (as defined by the U.S. Natural Resources Conservation Service):
- Fields where more than 30 percent of the soil surface is covered with plant residue at planting, apply a maximum of 2.0 lbs of active ingredient per acre as a broadcast spray.
- Fields where less than 30 percent of the soil surface is covered with plant residue at planting, apply a maximum of 1.6 lbs of active ingredient per acre as a broadcast spray.
- Apply a maximum of 2.0 lbs of active ingredient per acre as a broadcast spray.
Postemergence
- If no atrazine was applied prior to crop emergence, use a maximum rate of 2.0 lbs of active ingredient per acre.
- If a soil-applied application was made in the same calendar year, the combined preplant or preemergence and postemergence applications may not exceed 2.5 lbs of active ingredient per acre.
Safety Precautions for Using Atrazine
- Do not mix, load, or apply within 50 feet of drinking water wells, livestock wells, agricultural drainage wells, irrigation wells, abandoned wells, or sinkholes.
- Do not mix or load within 50 feet of intermittent streams, perennial streams, rivers, lakes, or reservoirs.
- Do not apply within 200 feet of lakes or reservoirs.
- Do not apply within 66 feet of the points where surface water runoff enters intermittent streams, perennial streams, or rivers. The 66-foot buffers should be planted to a crop or seeded with grass on highly-erodible land.