aminocyclopyrachlor + metsulfuron (Streamline)
Rate 7.5 to 11.5 oz/A
Time Apply to actively growing vegetation.
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.
Caution Do not apply to the root zone of desirable trees and shrubs. May injure or kill some grass species.
Site of action (aminocyclopyrachlor) Group 4 Synthetic auxin; (metsulfuron) Group 2: Acetolactate synthase (ALS) inhibitor
Chemical family (aminocyclopyrachlor) Pyridine; (metsulfuron) Sulfonylurea
aminocyclopyrachlor + imazapyr + metsulfuron (Viewpoint)
Rate 16 to 20 oz/A
Time Apply to actively growing vegetation.
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.
Caution Do not apply to the root zone of desirable trees and shrubs. May injure or kill some grass species.
Site of action (aminocyclopyrachlor) Group 4 synthetic auxin; (imazapyr, metsulfuron) Group 2: acetolactate synthase (ALS) inhibitor
Chemical family (aminocyclopyrachlor) Pyridine; (imazapyr) Imidazolinone; (metsulfuron) Sulfonylurea
imazapyr (Arsenal)
Rate 0.5 to 1 lb ae/A (3 to 4 pints/A)
Time Apply to actively growing vegetation.
Remarks Add 0.25% by volume of nonionic surfactant, or 1 to 2 pints/A methylated seed soil or crop oil concentrate to spray mixture. Re-treatment may be necessary.
Caution Imazapyr is nonselective; spray will injure or kill vegetation contacted.
Site of action Group 2: acetolactate synthase (ALS) inhibitor
Chemical family Imidazolinone
metsulfuron (Escort and others)
Rate 0.6 to 1.8 oz ai/A (1 to 3 oz/A)
Time Apply to actively growing vegetation.
Remarks Add 0.25% by volume of nonionic surfactant to spray mixture. Application sites differ between products; consult labels.
Caution Avoid contacting sensitive crops. Apply only to pasture, rangeland, and non-crop sites.
Site of action Group 2: acetolactate synthase (ALS) inhibitor
Chemical family Sulfonylurea
picloram (Tordon)
Rate 0.5 to 1 lb ae/A
Time Apply when plants are fully leaved and actively growing.
Caution Most formulations are restricted-use herbicides. See label for grazing restrictions. Do not contaminate water. Potatoes, beans, and many other crops are very sensitive to picloram. Do not use in diversified cropping areas. At rates above 0.5 lb ae/A (1 quart/A), apply only as spot treatment not to exceed 25% of a landowner's acreage in a given watershed in a single season.
Site of action Group 4: synthetic auxin
Chemical family Pyridine