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.
Remarks Re-treatment may be necessary. Add nonionic surfactant if not included in the formulation. Rain within 6 hours after application may reduce effectiveness. Allow at least 7 days after application before tillage or mowing of sprayed foliage. Combinations with imazapyr or triclopyr at the rates below have shown good results in testing in western Washington.
Caution Glyphosate is nonselective; spray will injure or kill vegetation contacted.
Site of action Group 9: inhibits EPSP synthase
Chemical family None generally accepted
imazapyr (Arsenal, Habitat, or others)
Rate Spot treatment at 1%: mix 1.5 fl oz of Habitat with each gal of water.
Time Apply to actively growing yellow archangel foliage.
Remarks Add 0.25% by volume of nonionic surfactant to spray mixture. Re-treatment may be necessary. Rain within 6 hr after application may reduce effectiveness. Allow at least 7 days after application before tillage or mowing of sprayed foliage.
Caution Imazapyr is nonselective; spray will injure or kill vegetation contacted.
Site of action Group 2: acetolactate synthase (ALS) inhibitor
Chemical family Imidazolinone
triclopyr ester (Garlon 4) or triclopyr amine (Garlon 3A) or triclopyr + 2,4-D (Crossbow)
Rate Spot treatment at 1.5%: mix 2 fl oz of Garlon 4, Garlon 3A, or Crossbow with each gal of water.
Time Apply to actively growing yellow archangel foliage.
Remarks Re-treatment may be necessary. Rain within 6 hr after application may reduce effectiveness. Allow at least 7 days after application before tillage or mowing of sprayed foliage.
Caution Use on rights-of-way, industrial sites, and for forestry (release and site preparation). Crossbow can be used on permanent pasture and rangeland, up to 1.5 lb ae/A. Observe all grazing and harvesting restrictions.
Site of action (all) Group 4: synthetic auxin
Chemical family (triclopyr) pyridine; (2,4-D) phenoxy acetic acid