Canada Thistle

Summer fallow and postharvest

clopyralid (Stinger)

Rate 0.125 to 0.250 lb ae/a (0.33 to 0.66 pint/a Stinger)

Time Apply to actively growing weeds from rosette up to bud stage.

Remarks Only weeds emerged at time of application will be affected.

Caution Do not rotate to beans, lentils, peas, potatoes, or broadleaf seed crops for at least 18 months after treatment, depending on annual precipitation. Carefully follow label rotation restrictions on many other crops.

Site of action Group 4: synthetic auxin

Chemical family Pyridine

clopyralid + 2,4-D amine (Curtail)

Rate 0.095 to 0.19 lb ae/a clopyralid + 0.5 to 1 lb ae/a 2,4-D amine (2 to 4 pints/a Curtail)

Time Apply to actively growing thistles, after most basal leaves emerge but before bud stage.

Remarks For best results, wait at least 20 days before disturbing treated areas (cultivation, mowing, fertilization with shank-type applicators) to allow thorough translocation. Apply in enough total spray volume to ensure good coverage. To control perennial weeds, such as Canada thistle, use the 4 pints/a rate in fallow.

Caution Do not plant wheat, barley, oats, grasses, or field corn within 30 days of application. Do not plant sugar beets for 5 months after treatment. Do not rotate to beans, lentils, peas, potatoes, or broadleaf seed crops for up to 18 months after treatment, depending on annual precipitation. Carefully follow label rotation restrictions on many other crops.

Site of action (both) Group 4: synthetic auxin

Chemical family (clopyralid) pyridine; (2,4-D) phenoxy acetic acid

In the crop

clopyralid + 2,4-D amine (Curtail)

Rate 0.095 to 0.126 lb ae/a clopyralid + 0.5 to 0.67 lb ae/a 2,4-D amine (2 to 2.66 pints/a Curtail)

Time Apply in spring, after grain begins tillering, up to jointing stage (first node on stem detectable).

Remarks Apply after most of the weed's basal leaves have emerged, but before bud stage.

Caution Do not plant sugar beets for 5 months after treatment. Do not rotate to beans, lentils, peas, potatoes, or broadleaf seed crops for up to 18 months after treatment, depending on annual precipitation. Carefully follow label rotation restrictions on many other crops.

Site of action (both) Group 4: synthetic auxin

Chemical family (clopyralid) pyridine; (2,4-D) phenoxy acetic acid

clopyralid + fluroxypyr (WideMatch)

Rate 0.094 to 0.125 lb ae/a clopyralid + 0.094 to 0.125 lb ae/a fluroxypyr (1 to 1.33 pints/a WideMatch)

Time Apply in spring from three-leaf crop growth stage up to and including flag leaf emergence.

Remarks Apply from rosette to bud (pre-flower) stage of growth.

Caution Do not grow chickpeas, lentils, or potatoes for 18 months after application. See label and supplemental labels for other crop rotation restrictions.

Site of action (both) Group 4: synthetic auxin

Chemical family (both) pyridine

pyroxsulam + fluroxypyr + clopyralid (PerfectMatch)

Rate 0.013 lb ai/a pyroxsulam + 0.097 lb ae/a fluroxypyr + 0.097 lb ae/a clopyralid (1 pint/a PerfectMatch)

Time Apply to actively growing wheat from 3-leaf to jointing stage. Treat after most weeds have emerged.

Remarks Apply with a nonionic surfactant (0.25 to 0.5% v/v) and ammonium sulfate (1.5 lb/a). PerfectMatch works best when weeds are actively growing and not hardened off by cold weather or drought. PerfectMatch is rainfast within 4 hours after application.

Caution Do not apply more than 1 pint/a per growing season. Limit nonionic surfactant rate to 0.25% v/v when tank mixing with up to 6 fluid oz/a of EC formulated product per acre. Do not use any surfactant when total EC products exceed 6 fluid oz/a. Do not apply within 60 days of harvest.

Site of action Group 2: acetolactate synthase (ALS) inhibitor and Group 4: synthetic auxin

Chemical family (pyroxsulam) triazolopyrimidine sulfonamide; (fluroxypyr and clopyralid) pyridine