Kentucky Bluegrass-East of the Cascades

Note Also see GRASS SEED-New and Established for herbicides that may be used on many species of grass grown for seed.

bromoxynil + pyrasulfotole (Huskie)

Rate 0.185 to 0.205 lb ai/A bromoxynil + 0.033 to 0.036 lb ai/A pyrasulfotole (13.5 to 15 oz/A Huskie)

Time Apply from preemergence to established Kentucky bluegrass. See label for weed size recommendations and application timings, but control of most species is best at the 15 fl oz/A rate when weeds have from one to six leaves. Two applications of Huskie can be made per year separated by at least 30 days.

Remarks For most consistent weed control under adverse growing conditions, add AMS or an ammonium nitrogen source as directed by the spray additives section of the label, but do not use these additives if grass crop injury is a concern. Huskie may be tank mixed with a variety of other broadleaf and grass herbicides and other pesticides; see label for instructions.

Caution See label for crop rotation restrictions. Wheat, triticale, and oats may be planted 1 month after application; most other crops may be planted 9 months after application. Do not graze or cut grass for forage within 7 days of application, or cut grass for hay within 30 days of application. Do not exceed 30 oz/A of Huskie per year. Aerial and chemigation applications are prohibited.

Site of action (bromoxynil) Group 6: photosystem II inhibitor;(pyrasulfotole) Group 28: inhibits 4hydroxyphenylpyruvatedioxygenase (4-HPPD)

Chemical family (bromoxynil) nitrile; (pyrasulfotole) isoxazole

dicamba (several trade names)

Rate 0.25 to 2 lb ae/A

Time Apply before broadleaf weeds have more than two true leaves in fall or late summer. Spray within 10 days after the first fall irrigation or fall rain to start weed germination.

Remarks Suppresses downy brome (cheatgrass), rattail fescue, and other grassy and broadleaf weeds in bluegrasses. Spray when soil is moist.

Caution Spray on well-established grass stands. Uniformly burn fields and mechanically spread unburned residues before spraying. See specific labels for grazing restrictions.

Site of action Group 4: synthetic auxin

Chemical family Benzoic acid

dimethenamid-P (Outlook)

Rate 0.66 to 0.98 lb ai/A (14 to 21 fl oz/A Outlook)

Time Apply in the fall before targeted weeds emerge, or in midwinter in a sequential-use program with other herbicides that control emerged weeds.

Remarks Grass seed crops must be established at least 1 year or have had at least one seed crop harvested before Outlook is applied. Apply higher rates where denser weed infestations are expected. Excessive straw on the field after harvest may reduce weed control. Sufficient rain or irrigation after application is needed for optimum weed control. May be applied by ground or by air (see label).

Caution Do not apply Outlook in tank-mixtures with other herbicides unless risk of crop injury is acceptable. Subsequent applications may injure crop. Do not allow livestock to graze treated fields for 60 days after application. Treated straw, seed, or seed screenings may be fed to livestock following harvest.

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

Chemical family Chloroacetamide

diuron (several trade names)

East of Cascades in Idaho, Oregon, and Washington

Rate 0.8 to 2.4 lb ai/A (1 to 3 lb/A of an 80DF formulation)

Time Apply in spring, before bluegrass begins rapid growth and when windgrass is small. Do not use on coarse, sandy soils. Note all precautions for diuron in the west of the Cascades Kentucky bluegrass entry. Special local needs label ID-870007 and ID-890007.

Caution There are several suppliers of diuron. See labels for crop and geographical restrictions.

Site of action Group 7: photosystem II inhibitor

Chemical family Substituted urea

ethofumesate (several trade names)

Rate 1.0 lb ai/A

Time Apply to moist soil surface after fall rains start. Apply to annual bluegrass preemergence through three-leaf stage and to rattail fescue, volunteer wheat and wild oat before the two-leaf stage.

Remarks Controls most annual broadleaf and grass weeds but not annual or perennial ryegrass.

Caution Spray only fields seeded at least 12 months. Burn or mechanically remove all crop residue before spraying. If previous crop was burned, rain or overhead irrigation must be sufficient to dissipate the charcoal residue. Do not tank mix with other herbicides. Do not graze treated fields. Do not rotate with any crops other than sugar beets or ryegrass for 12 months after application.

Site of action Group 16: unknown

Chemical family Benzofuran

flucarbazone (Everest 2.0)

Rate 0.027 lb ai/A (1.0 fl oz/A Everest 2.0)

Time Apply to recently emerged, actively growing weeds in first year stands when the crop is growing vigorously.

Remarks Apply only once per year. Straw and screenings from harvested fields may not be fed to livestock. Do not graze treated fields. Special local needs labels ID-110003, WA-110004, and OR-110008.

Caution Some cultivars may be injured; follow label directions. Do not apply to Kentucky bluegrass under stress. Do not use Everest 2.0 in annual production systems of Kentucky bluegrass grown for seed. Do not apply to Kentucky bluegrass after the establishment year. See additional cautions and use restrictions on the Everest 2.0 SLN labels for each state.

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

Chemical family Sulfonylaminocarbonyltriazolinone

flufenacet + metribuzin (Axiom DF)

Idaho, and Washington, and Oregon except for Jefferson County

Rate 0.3 to 0.4 lb ai/A flufenacet + 0.076 to 0.111 lb ai/A metribuzin (9 to 13 oz/A Axiom)

Time Apply before weeds emerge or no later than the two-leaf stage of volunteer grasses. Applications after mid-November may result in crop injury and/or poor weed control.

Remarks For established grass seed fields only (at least 1 year old, or after first seed harvest). Excessive straw on field after harvest may reduce weed control. Rain or irrigation after application is needed for good weed control.

Caution Do not apply in tank-mixtures with postemergence herbicides. Applying oxyfluorfen or photosynthesis-inhibiting postemergence herbicides within 4 weeks of Axiom applications may injure crop. Do not allow animals to graze treated fields for a minimum of 30 days following application. Preharvest interval is 120 days. Do not apply more than once per year.

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

Chemical family (flufenacet) oxyacetamide; (metribuzin) triazinone

mesotrione (Callisto)

Rate 0.094 to 0.188 lb ai/A (3 to 6 oz/A Callisto)

Time Apply preemergence to bare soil or early postemergence to bluegrass grown for seed.

Remarks Use higher application rates for control and suppression of grass and broadleaf weed species and for extended soil residual control. The addition of a crop oil concentrate or nonionic surfactant at a rate of 1% v/v is recommended to optimize activity of postemergence applications. In addition, urea ammonium nitrate at 2.5% v/v or ammonium sulfate at a rate of 8.5 lb/100 gal of spray solution may be added, but increases the risk of grass seed crop injury at rates above 3 oz/A of Callisto.

Caution Preharvest interval for seed and straw harvest is 60 days. Do not graze or feed forage from treated fields within 14 days after harvest of seed or straw, and at least 74 days after application. Do not exceed two applications or 9 oz/A of Callisto per year. Do not tank mix Callisto with other pesticides with EC formulations because crop injury will result from postemergence applications.

Site of action Group 28: inhibits 4hydroxyphenylpyruvatedioxygenase (4-HPPD)

Chemical family Triketone

metribuzin (several trade names)

In Oregon, only Crook, Deschutes, Jefferson, and Wasco counties

Rate 0.25 to 0.38 lb ai/A

Time When volunteer grasses are in the one- to two-leaf stage after fall rain or irrigation but before active spring growth.

Remarks Established grass crops only. Improve volunteer crop and grass weed control by adding a surfactant or crop oil blend at rates recommended on wetting agent label.

Caution Allow at least 28 days after application before grazing. Preharvest interval is 120 days. See additional cautions on individual labels.

Site of action Group 5: photosystem II inhibitor

Chemical family Triazinone

oxyfluorfen (Goal 2XL or Galigan 2E)

Oregon and Washington only

Rate 0.125 to 0.375 lb ai/A (8 to 24 oz/A Goal 2XL or Galigan 2E)

Time Apply on established stands in fall and midwinter, before and soon after weeds emerge. Apply first before weeds (grass) seedlings to be controlled exceed the two-leaf stage, preferably before December 15. Make final applications before mid-January.

Remarks Apply to established fields with at least six tillers per plant. Fields may be treated more than once, but do not exceed 24 oz/A total in a crop season. Goal and Galigan SLN labels vary by state.

Caution Applications may substantially discolor crop foliage; leaf chlorosis and reduced vegetative growth are typical plant responses. If tank mixed with diuron, do not exceed 1.2 lb ai/A diuron in a season. Review the specific oxyfluorfen SLN you are using for updated preharvest and grazing restrictions.

Site of action Group 14: protoporphyrinogen oxidase inhibitor

Chemical family Diphenylether

pendimethalin (Prowl H2O)

Rate 2 to 3 lb ai/A (4.2 to 6.3 pints/A Prowl H2O)

Time Apply at the beginning of significant fall rains and before weeds germinate. Treatments are most effective with adequate rain or overhead irrigation within 7 days after application.

Remarks For established grass fields only (six or more tillers). Prowl will not control established weeds. See label for specifics on tank-mixes with other herbicides. Removing excessive straw and crop residues may increase effectiveness. Fall applications made to perennial grasses which exceed 6 inches in height may result in reduced weed control due to reduced spray coverage to bare soil.

Caution May temporarily injure grass stands. Tank-mixtures and applications in extreme weather and to weak stands may increase crop injury. Do not harvest forage from treated fields within 45 days of application or harvest hay from treated fields within 60 days of application. The PHI for seed production is 90 days and grass seed screenings may not be used in livestock feed. Grass seed straw from treated fields may be fed to livestock and treated fields may be grazed after harvest. Refer to main labels for crop rotation restrictions.

Site of action Group 3: microtubule assembly inhibitor

Chemical family Dinitroaniline

primisulfuron-methyl (Beacon)

Oregon and Washington only

Rate 0.0356 lb ai/A (0.76 oz/A Beacon)

Time Apply to recently emerged, actively growing weeds no larger than the size listed on the label. The Kentucky bluegrass crop should be growing vigorously under favorable conditions at application time.

Remarks For postemergence applications on seedling and established stands of Kentucky bluegrass that have at least one tiller (4-5 leaves) but before jointing. Applications can be split, but do not exceed 0.76 oz/A Beacon in one crop season. Special local needs indemnified labels OR-960025 and WA-960002. Visit http://www.syngenta.com to obtain label and indemnification agreement.

Caution Applications may injure Kentucky bluegrass crop. Take special care in cleaning spray equipment; read label for directions. Do not apply to bluegrass under stress. Do not irrigate within 4 hours of application. Do not graze or use forage from treated fields until after harvest. Straw and screenings from harvested fields may be fed to livestock. Do not graze within 120 days of application. Preharvest interval is 60 days.

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

Chemical family Sulfonylurea

S-metolachlor (several trade names)

Rate 0.95 to 1.27 lb ai/A

Time Apply to established stands just before, during, or immediately after the first fall rains or an irrigation. Treat target weeds before they emerge.

Remarks Apply only to stands harvested for seed at least once, or planted at least 1 year before treatment. Rain or irrigation is required after application and before weeds emerge for best weed control.

Caution Apply only once per crop season. Do not apply after November 15. Tank-mixtures with postemergence herbicides may injure crop. See specific labels for grazing and feeding restrictions based on geography.

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

Chemical family Chloroacetamide

terbacil (Sinbar WDG)

Rate 0.4 to 0.8 lb ai/A (0.5 to 1 lb/A Sinbar WDG)

Time Apply in the fall, 4 to 6 weeks after burning fields, and after 2 inches of rain or irrigation has dispersed ash.

Remarks Controls downy brome (cheatgrass), rattail fescue, and other grassy and broadleaf weeds in bluegrass.

Caution One inch of moisture is required within 2 weeks after application for satisfactory weed control. Apply only to well-established fields harvested at least once for seed. Herbicide residues remain in soil up to 2 years. Do not graze treated fields. May injure crops stressed by weather, insects, or disease. See label for soil type restrictions.

Site of action Group 5: photosystem II inhibitor

Chemical family Uracil