Postemergence or Foliar Applied

bentazon (Basagran T&O)

Rate 0.5 lbs ai/a (16 oz/a Basagran)

Time Spring to early summer, depending on growth stage of weeds.

Remarks Use handheld pump-up back pack or knapsack sprayers. For control of Canada thistle and suppression of sedges and nutsedge where other options such as clopyralid are not possible. For Canada thistle, apply 2 pints/a when plants are between 8 inches tall and bud stage. Apply a second application 2 weeks later if needed. For nutsedge, apply 1.5 to 2 pints/a when plants are 6-8 in tall, and make a second application 7 to 10 days later if needed. Always add a crop oil concentrate. Use no more than 2 lb ai/a per year. Irrigate to make sure plants are actively growing before applying bentazon. Not as effective if temperatures drop below 50°F at night and in daytime does not exceed 70°F. Efficacy will be poor on drought stressed weeds.

Caution Apply as a directed spray, away from the crop. May apply over the top of some species if crop oil concentrate is not added and application is tested on a few plants to verify crop safety.

Site of action Group 6: photosystem II inhibitor

Chemical family Benzothiadiazole

clethodim (Envoy Plus and several others)

Rate 0.09 to 0.18 lb ai/a (12 to 32 oz/a).

Time Apply postemergence to actively growing annual or perennial grasses as listed on label.

Remarks For grass control in ornamental plantings. Controls annual bluegrass. Applications made to grass plants stressed by insufficient moisture, hot or cold temperatures, or to grass plants exceeding recommended growth stages may result in unsatisfactory control.

Caution Do not exceed 68 fl oz/a per season. Test for crop safety before applying to landscape species not listed on the label.

Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor

Chemical family Cyclohexanedione

clopyralid (CleanSlate)

Conifers, non-leguminous woody species, and ornamental grasses in landscapes

Rate 0.094 to 0.65 lb ae/a (0.25 to 1.5 pints/a depending on weed species present)

Time Apply to actively growing broadleaf weeds. For perennials such as Canada thistle, apply after most basal leaves have emerged and before bud stage.

Remarks Spot and directed applications are permissible. Surfactants or crop oils are generally not needed

Caution In Oregon, use is not permitted in landscapes except for golf courses. Do not allow sprays of this product to contact exposed suckers and/or roots of susceptible trees or shrubs or injury may occur. Do not apply to turf, except golf courses.

Site of action Group 4: synthetic auxin

Chemical family Pyridine

fenoxaprop ethyl (Acclaim Extra)

Rate 0.015 to 0.173 lb ai/a (3.5 to 39 fl oz/a) depending on weed species and growth stage

Remarks For grass control in many deciduous and evergreen trees, and in shrubs and herbaceous and flowering plants. Adjust rates depending on number of grass tillers (see label). Ensure thorough coverage to actively growing, susceptible grasses. Repeat after grass begins active growth, but do not exceed 120 fl oz/a per season. Inhibits fatty acid production, cell membranes, and new growth.

Caution Salvia and philodendron are not tolerant. Determine crop tolerance before extensive use.

Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor

Chemical family Aryloxyphenoxy propionate

fluazifop (Fusilade II Turf and Ornamental)

Rate 16 to 24 fl oz/a (0.25 to 0.375 lb ai/a)

Time Apply to actively growing grasses, or within 7 days after irrigation, as a directed spray with 0.25% nonionic surfactant when susceptible grasses are in the labeled growth stage.

Remarks Identify grasses, and adjust rates depending on susceptibility and stage of weed growth as label instructs. Results often are erratic if grasses are 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.

Caution Do not tank mix with other pesticides. Do not apply within 5 days of other pesticide treatments. Not for use on tulips.

Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor

Chemical family Aryloxyphenoxy propionate

glufosinate ammonium (Finale)

Spot or directed spray only

Rate 2 to 4 fl oz/gal of water

Time Apply to thoroughly cover actively growing weeds..

Remarks May be used to trim or edge landscape plantings.

Caution Do not apply as an over-the-top broadcast spray in ornamentals or shade trees. Avoid all contact with desirable foliage and green bark. REI 12 hr.

Site of action Group 10: glutamine synthase inhibitor

Chemical family Phosphinic acid

glyphosate (numerous product names)

Not for ground covers

Rate Spray: 1.5 to 5 lb ai/a or 1 to 2% solution for high-volume sprayers

Time Apply as directed spray toward base of bush, when weeds are actively growing or moving sugars to roots.

Remarks Use lower rates for annual weeds; consult label for higher rates and time of application for perennial weeds. Expedite Application Equipment contains a special formulation using small-droplet technology. Inhibits production of three amino acids and protein synthesis.

Caution Do not spray green foliage or green bark. If applications are repeated, do not exceed a total of 10.6 lb ai/a (10.6 quarts/a) per year. Repeated use in Australian orchards for several years has resulted in resistant biotypes. To avoid developing weed resistance, rotate chemicals and weed control practices.

Site of action Group 9: inhibits EPSP synthase

Chemical family None generally accepted

glyphosate (several products)

Not for ground covers

Rate Wiper: use 33% solution.

Time Apply 1 gal product to 2 gal water and wipe weeds. Avoid contact with desirable vegetation.

Remarks In severe infestations, reduce equipment ground speed or apply in two directions to ensure contact with wiper. (See remarks above.)

Site of action Group 9: inhibits EPSP synthase

Chemical family None generally accepted

halosulfuron-methyl (Sedgehammer)

Nutsedge control around established woody ornamentals in landscapes; not for use on roses or ground covers; directed spray only

Rate 0.031 to 0.062 lb ai/a (0.66 to 0.33 oz/a) to three- to eight-leaf nutsedge

Time Post-directed spray on established woody ornamentals.

Remarks For control of nutsedge. Use lower rate on light infestations and high rate on heavy infestations. Do not exceed 5.33 oz/a per year. Add a nonionic surfactant at 0.25 to 0.5% v/v. May tank mix with glyphosate. Not recommended on roses or ground covers.

Caution Do not apply over the top of desirable flowers, ornamentals, vegetables, trees, or shrubs. Avoid contact of this product to leaves of desirable plants since foliar injury, discoloration or death may result.

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

Chemical family Sulfonylurea

pelargonic acid (Scythe)

For ornamental trees and shrubs only

Rate Broadcast: use 5 to 10 gal product per 100 gal water. Spot spray: use 5 to 10% solution (6.67 to 13 fl oz/gal) to cover 400 sq ft.

Time Apply to thoroughly wet foliage, either broadcast to non-crop area or preemergence to ornamental crop; or spot treat and trim around ornamentals, trees, flower beds, paths, and drives.

Remarks Controls small, actively growing weeds and weakens established weeds by removing susceptible vegetation. Disrupts cell membranes, causing leakage and symptoms of leaf burn.

Site of action Group 26: unknown

Chemical family Carboxylic acid

sethoxydim (Segment)

For ornamental crops listed on label

Rate 0.28 to 0.47 lb ai/a (36 to 60 fl oz/a)

Time Apply at optimum growth stage of grasses listed on the label.

Remarks Identify susceptible grasses. 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. Quackgrass can be suppressed. Inhibits fatty acid production, cell, membranes, and new growth.

Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor

Chemical family Cyclohexanedione