glyphosate
Remarks Reported to control this plant, although data are lacking in the Pacific Northwest. Follow label instructions.
Site of action Group 9: inhibits EPSP synthase
Chemical family None generally accepted
imazapyr (Arsenal)
Rate 0.75 to 1 lb ae/A or as a 1% solution with methylated seed oil adjuvant
Time Apply to actively growing foliage after plants bolt and through the fall.
Remarks Always add the appropriate surfactant.
Caution Before using, note crop rotation restrictions.
Site of action Group 2: acetolactate synthase (ALS) inhibitor
Chemical family Imidazolinone
metsulfuron (Escort)
Rate 1.2 oz ai/A (2 oz/A)
Time Apply to actively growing plants.
Remarks Using a nonionic or silicone surfactant increases effectiveness.
Caution Apply only to non-cropland sites.
Site of action Group 2: acetolactate synthase (ALS) inhibitor
Chemical family Sulfonylurea