Pepperweed, perennial (Lepidium latifolium)

2,4-D amine

Rate 4 lb ae/a

Time Apply at the bud stage of growth.

Remarks Repeat treatments if needed. Good grass cover helps control perennial pepperweed.

Caution Avoid drift to sensitive crops.

Site of action Group 4: synthetic auxin

Chemical family Phenoxy acetic acid

aminocyclopyrachlor + chlorsulfuron (Perspective)

Rate 1.8 to 3.2 oz/a aminocyclopyrachlor + 0.7 to 1.3 oz/a chlorsulfuron (4.5 to 8 oz/a of product)

Time Apply to actively growing plants in spring.

Remarks Adjuvants can be used; these include methylated seed oils 0.5 to 1% v/v, nonionic surfactants at 0.25 to 1% v/v, and crop oil concentrates at 1% v/v. Can be applied using an invert emulsion rather than water.

Caution Even low rates can kill nontarget tree and shrub species so avoid application within a distance equal to the tree height of the sensitive species. Do not allow spray to drift off target. Can injure several grass species including bromes, as well as basin wildrye.

Site of action (aminocyclopyrachlor) Group 4: Synthetic auxin; (chlorsulfuron) Group 2: ALS inhibitor

Chemical family (aminocyclopyrachlor) Pyrimidine carboxylic acid; (chlorsulfuron) Sulfonylurea

chlorsulfuron (Telar)

Rate 0.75 oz ai/a (1 oz/a)

Time Apply in fall or in spring up through bloom stage.

Remarks Adding surfactant and/or 2,4-D improves control.

Caution Do not let spray drift onto sensitive crops. Labeled for use on pasture, range, Conservation Reserve Program (CRP), and non-cropland only.

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

Chemical family Sulfonylurea

imazapic (Plateau)

Rate 0.125 to 0.188 lb ai/a

Time Apply after blossoms open (full bloom) until plants desiccate. Fall rosettes also may be treated if moisture permits.

Remarks Lightly cover foliage with spray solution. Add 1 quart/a methylated seed oil.

Caution Before using, note crop rotation restrictions.

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

Chemical family Imidazolinone

metsulfuron (Escort)

Rate Escort: 0.6 to 1.2 oz ai/a (1 to 2 oz/a)

Time Apply to actively growing perennial pepperweed.

Remarks Selective to grasses. Use a surfactant.

Caution Do not allow spray to drift onto sensitive crops. Apply only to non-crop sites.

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

Chemical family Sulfonylurea