clethodim (Select Max)
Rate 0.07 to 0.12 lb ai/A (9 to 16 oz/A Envoy Plus)
Time Apply postemergence to actively growing annual or perennial grasses as listed on label.
Remarks Consider environmental and plant growth conditions that affect leaf uptake (see label). Add 0.25% v/v nonionic surfactant to improve efficacy. Use higher rates to control perennial grasses. For repeat applications make on a minimum of a 14-day interval. PHI 7 days.
Caution Do not exceed 64 fl oz/A per season. Do not apply over top of plants. Do not apply within 1 year of harvest.
Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family Cyclohexanedione
fluazifop (Fusilade DX)
Rate 0.25 to 0.375 lb ai/A (16 to 24 oz/A Fusilade DX) depending on target species and growth stage
Time Apply to actively growing grasses, or within 7 days after irrigation, as a directed spray with 1% crop oil or 0.25% nonionic surfactant.
Remarks Identify grasses and adjust rates depending on susceptibility and stage of weed growth, according to label instructions. Results often are erratic on grasses stressed from lack of vigor, drought, high temperature, or low fertility. More mature grasses and quackgrass can be controlled but may require two applications. Annual bluegrass and all fine fescues resist treatment. Inhibits fatty acid production, cell membranes, and new growth. PHI 1 day.
Caution Grazing is prohibited.
Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family Aryloxyphenoxy propionate
glyphosate (numerous products)
Rate See label
Time Apply to actively growing weeds.
Remarks Avoid contact with green foliage or suckers of crop. Preharvest interval is 14 days.
Caution Do not exceed 12.8 pints/A per year. Follow all precautions on label.
Site of action Group 9: inhibits EPSP synthase
Chemical family None generally accepted
isoxaben (Gallery 75DF or Trellis SC)
New plantings and bearing crops
Rate 0.5 to 1 lb ai/A (16 to 31 fl oz/A product) depending on target weed species
Time Apply after transplanting to firm soil, or during the nonbearing year of alternate-year production. Apply before weeds germinate and emerge. Requires sprinkler irrigation or rain (0.5 inch or more) to incorporate.
Remarks PHI 60 days. Controls several broadleaf weeds but no grasses. Partially suppresses field bindweed and curly dock at 1 lb ai/A.
Caution Do not apply more than 1 lb ai/A/year.
Site of action Group 21: inhibits cell wall biosynthesis Site B
Chemical family Benzamide
pendimethalin (Satellite Hydrocap)
New plantings and bearing crops
Rate 2 to 6 lb ai/A (2 to 6.3 quarts/A product) depending on target weed species
Time Apply after transplanting to firm soil. Apply before weeds germinate and emerge. Requires sprinkler irrigation or rain (0.5 inch or more) to incorporate. May be apply preplant incorporated. May also be applied through sprinkler and drip irrigation system.
Remarks PHI 30 days. Controls several broadleaf weeds but no grasses.
Caution Do not apply more than 6 lb ai/A/year. Use lower rates on coarse soil to avoid damage.
Site of action Group 3: microtubule assembly inhibitor
Chemical family Dinitroaniline
trifluralin (2%) + isoxaben (0.5%) (Snapshot 2.5TG)
New plantings and nonbearing crops in alternate-year systems
Rate 2.5 to 5 lb ai/A (100 to 200 lb/A Snapshot 2.5TG), depending on target weed species, length of control desired, and soil conditions.
Time Apply after transplanting to firm soil or during the nonbearing year of alternate-year production. Apply before weeds germinate. Requires sprinkler irrigation or rain (0.5 inch or more) to activate. Results are best if activated within 3 days of application.
Remarks Controls several broadleaf weeds and grasses. Partially suppresses field bindweed and curly dock at 200 lb/A.
Caution Do not apply within 1 year of harvest.
Site of action (isoxaben) Group 21: inhibits cell wall synthesis Site A; (trifluralin) Group 3: microtubule assembly inhibitor
Chemical family (isoxaben) benzamide; (trifluralin) dinitroaniline
napropamide (Devrinol DF-XT, Devrinol 2-XT)
Rate 4 lb ai/A (8 lb/A Devrinol DF-XT, 8 quarts/A Devrinol 2-XT)
Time Apply after transplanting to a firm, weed free soil surface. Apply in fall through spring for early weed emergence control.
Remarks The day of treatment, wet soil 2 to 4 inches deep to reduce degradation by sun and to activate herbicide. If convenient, shallow mechanical incorporation appears to improve activation. Inhibits root growth.
Site of action Group 15: inhibits very long chain fatty acid synthesis
Chemical family Acetamide
oryzalin (Surflan AS, Fugitive)
Rate 2 to 6 lb ai/A (2 to 6 quarts/A product) Maximum allowed per season: 12 lb ai/A (12 quarts/A product)
Time Apply after transplanting to firm soil, before weeds germinate.
Remarks Do not allow transplant roots to contact treated soil. Requires sprinkler irrigation, rain, or shallow cultivation (1 to 2 inches) for activation. Inhibits cell division or mitosis, primarily in roots.
Site of action Group 3: microtubule assembly inhibitor
Chemical family Dinitroaniline
sethoxydim (Poast)
Rate 0.47 lb ai/A (2.5 pints/A Poast) Maximum allowed per season: 0.94 lb ai/A (5 pints/A Poast)
Remarks Identify susceptible grasses and apply at optimum growth stage listed on the label. Add 2 pints/A of a nonphytotoxic crop oil concentrate to improve leaf absorption. Control often is erratic on grasses stunted or stressed from drought, high temperatures, or low fertility. Resistant grasses include annual bluegrass and all fine fescues, but quackgrass can be suppressed. Inhibits fatty acid production, cell membranes, and new growth. Preharvest interval is 45 days.
Caution Do not allow livestock to graze or feed in treated field.
Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family Cyclohexanedione
simazine (Princep 4L)
Rate 2 to 4 lb ai/A (2 to 4 quarts/A Princep 4L) Maximum allowed per season: 4 lb ai/A (4 quarts of Princep 4L)
Time Apply in spring within 2 weeks after transplanting if soil is settled around plant roots. Apply before weeds are established. In plantings less than 6 months old, use half the above rate.
Remarks Requires sprinkler irrigation or rain to activate.
Caution Do not apply on sandy or gravelly soils.
Site of action Group 5: photosystem II inhibitor
Chemical family Triazine