Winter Wheat—Irrigated, East of Cascades
Bob Parker and Dan Ball 
Revised December 8, 2008
WINTER WHEAT—Irrigated East of Cascades—Wild Oat and Grasses
•  triallate (Far-Go)
Rate  1.25 lb ai/A (1.25 quarts/A Far-Go)
Time  Apply and incorporate before or after planting but before wild oat germinates.
Remarks  Herbicide must be incorporated immediately 1 to 2 inches deep. Soil should be in good tilth with residue incorporated. Do not graze livestock on treated crop. Do not use on clay knobs. Do not use on fields where seeding will be shallow.
Site of action  Group 8: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family  Thiocarbamate
•  diclofop (Hoelon)
Rate  0.75 to 1 lb ai/A (2 to 2.67 pints/A Hoelon)
Time  Apply before grass weeds reach the four-leaf growth stage. Apply before jointing stage of wheat growth.
Remarks  Diclofop has some soil activity and controls some later-germinating grasses. Control is best if most grass weeds are in the one- to three-leaf stage of growth and less herbicide is required. Apply in at least 10 gal/A water carrier. Do not let livestock graze treated fields. Do not apply more than once per growing season. See Hoelon label for tank-mixes with Harmony Extra and bromoxynil. Do not apply other broadleaf herbicides within 5 days of diclofop application or weed control will be reduced.
Caution  A restricted-use herbicide.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
•  tralkoxydim (Achieve)
Rate  0.18 to 0.24 lb ai/A (0.44 to 0.6 lb/A Achieve 40DG or 6.9 to 9.2 fl oz/A Achieve Liquid)
Time  Apply to actively growing wild oats when in one- to six-leaf stage.
Remarks  Use the high rate when soil is dry, weeds are large, weed population is high, or crop canopy is dense. Add Supercharge adjuvant to the spray solution at 4 pints/100 gal water (0.5% v/v). Add ammonium sulfate to the spray solution at 15 lb/100 gal when spray water contains over 400 ppm bicarbonate ions or the when weeds are stressed.
Caution  Do not harvest for 60 days after application. Do not apply to crops that have a heavy dew cover. Cereal grains and leafy crops may be planted 30 days after application; all other rotational crops can be planted 106 days after application. Do not tank-mix with amine formulations of labeled herbicides or any other herbicide or pesticide or product not recommended on the Achieve label; poor grass control and/or unacceptable crop injury may result. Weed control can be reduced if Achieve is applied to fields treated with sulfonylurea herbicides within the previous 12 mo.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Cyclohexanedione
•  mesosulfuron-methyl (Osprey)
Rate  0.009 to 0.0134 lb ai/A (3.2 to 4.75 oz/A Osprey)
Time  Fall or spring: Apply as a postemergence broadcast spray to young, actively growing weeds (one-leaf to two-tiller growth stage). Apply from crop emergence to jointing stage.
Remarks  For Italian ryegrass, use 4.75 oz/A Osprey. If wild oat is the only target weed, use 3.2 oz/A Osprey. A nonionic surfactant (0.5% v/v) with ammonium nitrogen (1 to 2 quarts/A) or ammonium sulfate fertilizer (1.5 to 3 lb/A) must be tank-mixed with Osprey. Do not exceed one application or 4.75 oz/A Osprey per winter wheat season.
Caution  Do not apply through irrigation systems. Certain crops cannot be replanted for up to 12 mo after treatment; see label for crop rotation restrictions. Crop may be affected if frost occurs shortly after application to actively growing wheat. See label for broadleaf tank-mix options with Osprey and additional cautions.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
•  fenoxaprop (Puma)
Rate  0.0825 lb ai/A (0.66 pint/A Puma)
Time  Apply to actively growing grass weeds in the one- to two-tiller stage of growth and when crop has emerged up to six-leaf stage.
Remarks  Adequate soil moisture and temperatures lower than 85°F for several days before application enhance grass control. Grass weeds germinating after fenoxaprop application will not be controlled.
Caution  Do not harvest within 70 days of application. Do not tank-mix with amine formulations of labeled herbicides or any other herbicide or pesticide or product not specifically recommended on the Puma label; poor grass control may result.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
•  clodinafop (Discover)
Rate  0.05 to 0.625 lb ai/A (3.2 to 4 oz/A Discover)
Time  Apply to wheat from two-leaf to emergence of fourth tiller. Apply to wild oat in the one- to six-leaf stage and to green and yellow foxtails  in one- to five-leaf stage. Apply to Italian ryegrass and Persian darnel at one- to five-leaf stage.
Remarks  Wild oat will be controlled up to emergence of the fourth tiller. Use DSV adjuvant (supplied with Discover) at 10.2 oz/A for wild oat and 12.8 oz/A for other grass weeds. Do not graze treated fields for 30 days after application. Do not harvest for 60 days after application. Do not apply to winter wheat in the fall. Special local needs labels OR‑030004, ID‑010005, and WA‑010010.
Caution  Avoid drift to crop oats and corn. Small grains except wheat may be planted 30 days after applying.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
WINTER WHEAT—Irrigated East of the Cascades—Annual Grass and Broadleaf Weeds
•  pyroxsulam (PowerFlex)
Rate  3.5 oz PowerFlex/A
Time  Apply in the spring or fall to actively growing winter wheat from 3-leaf to jointing stage when the main flush of target weeds shown in the table on the label have emerged.
Remarks  Controls certain broadleaf and grass weeds. When not tank-mixed use an 80% active ingredient nonionic surfactant at1 to 2 quarts/100 gal spray solution nonionic surfactant or crop oil concentrate at 0.8 gal/100 gal spray solution to enhance weed control. Occasional temporary slight yellowing or height reduction of the wheat may be observed.
Caution  Do not apply more than 3.5 oz of PowerFlex/A per growing season. Do not use additives that lower the spray solution below pH 6.0. Do not graze within 7 days of application or cut for hay within 28 days following application. Do not harvest within 60 days of application. Refer to the label for specific crop rotation intervals.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea

WINTER WHEAT—Irrigated East of Cascades—Broadleaf Weeds
•  2,4-D
Rate  0.25 to 0.95 lb ae/A
Time  Apply in spring after wheat has at least four tillers and 12 leaves but before wheat begins to joint.
Remarks  Do not apply to winter wheat in the fall. Avoid drift to susceptible plants. Check 2,4-D regulations for your area. Do not graze treated field or feed straw within 14 days after treatment.
Caution  Do not permit 2,4-D to drift off target.
Site of action  Group 4: synthetic auxin
Chemical family  Phenoxy acetic acid
•  MCPA
Rate  0.25 to 1 lb ae/A
Time  Apply in spring to wheat with at least three tillers and nine leaves but before jointing.
Remarks  MCPA typically is less likely to injure wheat than 2,4-D and may be applied somewhat earlier in spring. Generally, the same use precautions and remarks for 2,4-D apply to MCPA.
Caution  Do not permit MCPA to drift off target.
Site of action  Group 4: synthetic auxin
Chemical family  Phenoxy acetic acid
•  dicamba (Banvel, Rifle, or Clarity)
Rate  0.06 to 0.125 lb ae/A
Time  Apply before wheat begins to joint.
Remarks  Other herbicides often are combined with dicamba and sold under various trade names. See label for rates, time of application, use restrictions, and precautions for each mixture.
Caution  Do not permit dicamba to drift off target.
Site of action  Group 4: synthetic auxin
Chemical family  Benzoic acid
•  bromoxynil (Buctril 2EC)
Rate  0.5 lb ai/A (2 pints/A Buctril)
Time  After wheat emerges and before weeds are in four-leaf stage, 2 inches high, or 1 inch in diameter, whichever is first.
Remarks  Bromoxynil controls certain 2,4-D-resistant weeds. Thorough spray coverage is essential. Do not graze treated fields for 45 days after application.
Caution  0.5 lb ai/A may be used with chemigation.
Site of action  Group 6: photosystem II inhibitor
Chemical family  Nitrile
•  bromoxynil + MCPA (Bronate Advanced)
Rate  0.25 to 0.5 lb ai/A bromoxynil + 0.25 to 0.5 lb ai/A MCPA (0.8 to 1.6 pints/A Bronate Advanced)
Time  Apply after wheat has at least three to four leaves and before weeds are wider than 1 to 1.5 inches.
Remarks  Controls many 2,4-D-tolerant weeds and generally injures wheat less than 2,4-D does.
Caution  Do not let MCPA drift off target. May use 0.5 lb ai/A bromoxynil + 0.5 lb ai/A MCPA with chemigation.
Site of action  (bromoxynil) Group 6: photosystem II inhibitor; (MCPA) Group 4: synthetic auxin
Chemical family  (bromoxynil) nitrile; (MCPA) phenoxy acetic acid
•  clopyralid + 2,4-D amine (Curtail)
Rate  0.095 to 0.126 lb ae/A clopyralid + 0.5 to 0.67 lb ae/A 2,4-D amine (2 to 2.66 pints/A Curtail)
Time  Apply in spring to young, actively growing weeds after grain begins tillering up to jointing stage (first node on stem detectable).
Remarks  Consult label for crop rotation restrictions before using Curtail. This combination is particularly effective on members of the sunflower family such as Canada thistle and mayweed. Controlling tough winter annual weeds such as corn gromwell and fiddleneck requires tank-mixing with other herbicides. Check Curtail label for details on mixtures. Apply to Canada thistle after most basal leaves emerge but before bud stage.
Caution  Do not plant wheat, barley, oats, grasses, or field corn within 30 days of application. Do not plant sugar beets in the same growing season after treatment. Do not rotate to beans, lentils, peas, potatoes, or broadleaf seed crops for at least 18 mo after treatment, depending on annual precipitation. Carefully follow label on rotation restrictions on many other crops.
Site of action  (both) Group 4: synthetic auxin
Chemical family  (clopyralid) phenoxy acetic acid; (2,4-D) pyridine
•  fluroxypyr (Starane)
Rate  0.125 to 0.25 lb ae/A
Time  Apply to actively growing wheat from the two-leaf up to the flag-leaf stage.
Remarks  Apply to actively growing weeds under 8 inches tall. Controls only weeds emerged at treatment.
Caution  Plant only wheat, barley, or oats within 120 days after applying fluroxypyr. Do not apply in more than 40 gal/A water. Do not apply more than once per season. Preharvest interval is 40 days.
Site of action  Group 4: synthetic auxin
Chemical family  Pyridine
•  thifensulfuron (Harmony GT) +
•  another broadleaf herbicide with a different mode of action
Rate  0.23 to 0.45 oz ai/A (0.3 to 0.6 oz/A Harmony GT) + 0.25% nonionic surfactant
Time  After crop is in two-leaf stage but before flag leaf is visible.
Remarks  Results are best when weeds are young and actively growing, temperatures are 60°F or higher, and soil moisture is adequate before, during, and immediately after treatment. Sequential treatments may be made if the Harmony GT total does not exceed 1 oz/A.
Caution  Do not let spray drift to adjacent crops or land. Do not apply during an air temperature inversion. Immediately after spraying, thoroughly clean chemical from mixing and spraying equipment. Do not plant any crop other than wheat, barley, field corn, or oats within 45 days after application.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
•  thifensulfuron + tribenuron (Harmony Extra) +
•  another broadleaf herbicide with a different mode of action
Rate  0.23 to 0.45 oz ai/A (0.3 to 0.6 oz/A Harmony Extra) + 0.25% nonionic surfactant
Time  After crop is in two-leaf stage but before flag leaf is visible.
Remarks  Results are best if weeds are young and actively growing, temperature is 60°F or higher, and soil moisture is adequate before, during, and immediately after treatment. Do not let spray drift onto adjacent crops or land. Refer to most recent grass herbicide label to determine tank-mix restrictions.
Caution  Do not apply during an air temperature inversion. Right after spraying, thoroughly clean mixing and spray equipment. Wheat, barley, and oats may be replanted any time after application. After application, sugar beets, winter rape, and canola can be planted in 60 days, all other crops can be planted in 45 days.
Site of action  (both) Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  (both) sulfonylurea
•  thifensulfuron + tribenuron (Affinity Broadspec) +
•  another broadleaf herbicide with a different mode of action
Rate  0.4 to 1 oz/A (use 0.4 to 0.6 oz/A in combination with other registered herbicides) + 0.25% nonionic surfactant
Time  Apply after wheat is in two-leaf stage but before flag leaf is visible.
Remarks  Results are best if weeds are young and actively growing, temperatures are 60°F or higher, and soil moisture is adequate before, during, and immediately after treatment. Refer to most recent grass herbicide label to determine tank-mix restrictions.
Caution  Do not let this herbicide drift off target. Do not plant any crop except wheat or barley for 45 days after application. Sugar beets, winter rape, and canola cannot be planted until 60 days after application.
Site of action  (both) Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  (both) sulfonylurea
•  thifensulfuron + tribenuron (Affinity TankMix) +
•  another broadleaf herbicide with a different mode of action
Rate  0.6 to 1 oz/A + 0.25% nonionic surfactant
Time  Apply after wheat is in two-leaf stage but before flag leaf is visible.
Remarks  Results are best if weeds are young and actively growing, temperatures are 60°F or higher, and soil moisture is adequate before, during, and immediately after treatment. Refer to most recent grass herbicide label to determine tank-mix restrictions.
Caution  Do not permit this herbicide to drift off target. Do not plant any crop except wheat or barley for 45 days after application. Sugar beets, winter rape, and canola cannot be planted until 60 days after application.
Site of action  (both) Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  (both) sulfonylurea
•  tribenuron (Express) +
•  another broadleaf herbicide with a different mode of action
Rate  0.13 to 0.25 oz ai/A (0.17 to 0.33 oz/A Express) + 0.25% nonionic surfactant
Time  After crop is in two-leaf stage but before flag leaf is visible.
Remarks  Results are best if weeds are young and actively growing, temperatures are 60°F or higher, and moisture is adequate before, during, and immediately after treatment.
Caution  Do not allow spray to drift to adjacent crops or land. Do not apply during an air temperature inversion. Immediately after spraying, thoroughly clean mixing and spraying equipment. Wheat, barley, and oats may be replanted any time after applying. Sugar beets, winter rape, and canola can be planted 60 days after applying. All other crops can be planted 45 days after applying.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
•  carfentrazone (Aim)
Rate  0.008 to 0.031 lb ai/A (0.5 to 2 fl oz/A Aim EC)
Time  Apply to actively growing weeds up to 4 inches tall and rosettes less than 3 inches across and to wheat up to the jointing stage.
Remarks  Adjust rate for weed species and density of weed stand. Add 0.25% (v/v) nonionic surfactant. If wheat grows in very dry soil, a sprayable liquid nitrogen fertilizer may be used in addition to the nonionic surfactant. After applying Aim, registered crops may be planted anytime. Root and leafy vegetables may be planted 30 days after application. All other crops may be planted 12 mo after application. Good spray coverage is essential.
Caution  Crop injury may increase with tank-mixes of carfentrazone with emulsifiable concentrate (EC) formulations of other herbicides, fungicides, or insecticides or with crop oil concentrate, methylated seed oil, or silicone-based adjuvants or when applied at rates above 0.16 lb ai/A (1 fl oz/A Aim EC or Aim EW). Adding nitrogen or ammonium sulfate with nonionic surfactant may increase leaf injury. Do not exceed 0.031 lb ai/A Aim per season.
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  Triazinone
•  carfentrazone + 2,4-D (Rage D-Tech) 
Rate  0.38 to 0.76 lb ai/A (8 to 16 fl oz/A Rage D-Tech)
Time  Apply from 3-tiller stage to jointing of grain and when weeds are up to 4 to 6 inches tall.
Remarks  Include a nonionic surfactant at 0.25% v/v (2 pints/100 gal spray solution). A high-quality sprayable liquid nitrogen fertilizer may be used at 2% to 4% v/v or AMS at 2 to 4 lb/A in addition to the nonionic surfactant. Adjuvants other than nonionic surfactants are not recommended. Consult label for more information. 
Caution  Do not exceed 1.513 lb ai/A Rage D-Tech per year. Tank-mixes with EC or ester formulations of other herbicides may increase leaf speckling. Do not apply to foliage wet from dew, rain, or irrigation, or crop injury may increase. 
Site of action  Group 14: protoporphyrinogen oxidase inhibitor; Group 4: synthetic auxin
Chemical family  (carfentrazone) triazinone; (2,4-D) phenoxy acetic acid

WINTER WHEAT—Irrigated East of Cascades—Preharvest Weed Control
•  glyphosate (several products)
Rate  0.38 to 0.75 lb ae/A (16 to 32 oz/A Roundup)
Time  Hard dough stage. Less than 30% grain moisture. Apply at least 7 days before harvest.
Remarks  Controls annual and perennial weeds. Add 0.5% to 1% (v/v) agriculturally approved nonionic surfactant. Apply in 3 to 10 gal/A by air or ground.
Caution  Do not apply to wheat grown for seed.
Site of action  Group 9: inhibits EPSP synthase
Chemical family  None generally accepted
•  glyphosate + 2,4-D (Landmaster BW)
Rate  0.375 to 0.59 lb ae/A glyphosate + 0.63 to 0.98 lb ae/A 2,4-D (54 to 84 oz/A product)
Time  Hard dough stage (under 30% grain moisture). Apply at least 7 days before harvest.
Remarks  Controls annual broadleaf weeds and suppresses field bindweed). Apply in 3 to 10 gal/A by air or ground.
Caution  Do not apply to wheat grown for seed. Do not feed treated straw to livestock. Do not permit dairy animals or meat animals being finished for slaughter to forage treated grain fields within 2 weeks after treatment.
Site of action  (glyphosate) Group 9: inhibits EPSP synthase; (2,4-D) Group 4: synthetic auxin
Chemical family  (glyphosate) none generally accepted; (2,4-D) phenoxy acetic acid
•  2,4-D (several trade names)
Rate  0.48 to 1.425 lb ae/A (1 to 3 pints/A product)
Time  Apply when wheat is in at least the soft dough stage.
Remarks  Consult label; labels differ among manufacturers. Results are best on actively growing weeds. Use higher rate to suppress perennial weeds.
Caution  Do not graze dairy animals or meat animals being finished for slaughter in treated fields within 14 days of application. If using 1.425 lb/A (3 pints/A), do not feed treated straw to livestock.
Site of action  Group 4: synthetic auxin
Chemical family  Phenoxy acetic acid
•  carfentrazone (Aim)
Rate  0.016 to 0.031 lb ai/A (1 to 2 fl oz/A Aim EC)
Time  Apply when crop is mature and the grain has begun to dry down.
Remarks  Adding a nonionic surfactant, methylated seed oil, or crop oil concentrate is required. Good spray coverage is essential. After applying Aim, registered crops may be planted anytime. Root and leafy vegetables may be planted 30 days after application. All other crops may be planted 12 mo after application. 
Caution  Do not exceed 0.031 lb ai/A Aim (2 fl oz/A product) per season including that which may have been applied during the growing season.
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  Triazinone
•  carfentrazone + 2,4-D (Rage D-Tech)
Rate  0.76-1.51 lb ai/a (16 to 32 fl oz/A Rage D-Tech)
Time  Apply when grain is in hard dough stage to control weeds that will interfere with harvest.
Remarks  A nonionic surfactant, methylated seed oil, or crop oil concentrate is required. Coverage is essential for satisfactory performance.
Caution  Do not exceed 1.513 lb ai/A Rage D-Tech per year. Do not apply closer than 7 days before harvest. Do not feed straw to livestock. Do not graze dairy or meat animals being finished for slaughter for 14 days after application.
Site of action  Group 14: protoporphyrinogen oxidase inhibitor , Group 4: synthetic auxin
Chemical family  (carfentrazone) triazinone; (2,4-D) phenoxy acetic acid