Weed Management Handbook

Remarks Although PNW data are preliminary, imazapyr and glyphosate provided good control in initial trials when applied as cut stem treatments.

Site of action (imazapyr) Group 2: acetolactate synthase (ALS) inhibitor; (glyphosate) Group 9: inhibits EPSP synthase

Chemical family (imazapyr) imidazolinone; (glyphosate) none generally accepted

glyphosate

Rate Full strength for cut stem treatments.

Time Apply any time of year, including when plants are dormant or actively growing.

fluazifop (Fusilade)

Rate 2 to 4 oz ai/A (8 to 16 fl oz/A)

Time Apply in spring to control seedlings, and treat established plants through summer until fall.

Remarks Two to three years of treatment will be necessary to achieve control. Fine leaf fescues are tolerant to fluazifop. Native broadleaves should not be injured by fluazifop.

2,4-D amine

Rate Broadcast treatment: 2 lb ae/A (2.1 quarts/A)

Time Apply in spring to seedlings. Treatments from mid-summer to autumn may help control more established plants.

Remarks 2,4-D is usually not able to fully control these species, so combining with other products is generally recommended for full control.

Remarks Fenoxaprop, flufenacet, pendimethalin, pinoxaden, pyroxulam, and triallate are used in cereal crops. Grass herbicides (clethodim, fluazifop, quizalofop, and sethoxydim) and glyphosate may also be effective. See specific crop section for these herbicides in cropland recommendations.

Remarks Control is unknown. No herbicides are currently recommended.

Remarks Although PNW data are preliminary, foliar-applied imazapyr and cut-stem treatments of imazapyr, picloram, or triclopyr + 2,4-D gave good results in initial trials.

Site of action (imazapyr) Group 2: acetolactate synthase (ALS) inhibitor; (2,4-D, picloram, triclopyr) Group 4: synthetic auxin

Chemical family (imazapyr) imidazolinone; (2,4-D phenoxy acetic acid; (picloram, triclopyr) pyridine

aminopyralid + metsulfuron (Opensight, Chaparral)

Rate 2.5 to 3 oz product/A

Time Apply preemergence in the fall or postemergence in spring to seedlings or rosettes.

Site of action (metsulfuron) Group 2: acetolactate synthase (ALS) inhibitor; (aminopyralid) Group 4: synthetic auxin

Remarks Although PNW data are preliminary, metsulfuron, sulfometuron, glyphosate, aminocyclopyrachlor, and imazapyr appear promising in initial trials.

Site of action (metsulfuron, sulfometuron, imazapyr) Group 2: acetolactate synthase (ALS) inhibitor; (glyphosate) Group 9: inhibits EPSP synthase; (aminocyclopyrachlor) Group 4: synthetic auxin

glyphosate

Rate Spot treatment at 2.5%: mix 3.2 fl oz of 3 lb ae glyphosate formulation with each gal of water in a backpack sprayer.

Time Apply to actively growing yellow archangel foliage.