Table 1. Herbicides that have activity on musk thistle.
Common Name
Trade Name
Rate/A
Efficacy
Comments
2,4-D
Many
1.5-2 pt.
Fair
See specific product's label for details. Amine and ester formulations are both effective. Do not graz dairy cattle for 7 days after treatment and remove livestock from treated fields at least 3 days before slaughter. Do not apply to grass in the boot to milk state if seed productions are desired. Can injure legumes.
Dicamba
Banvel, Clarity, Sterling, Oracle
1.5-3 pt.
Excellent
Labeled in pasture, hay, non-crop lands. Remove livestock from treated fields at least 30 days before slaughter. Do not graze lactating animals for 7 to 10 days depending on rate used. See specific product label. Will injure legumes.
Clopyralid
Stinger
0.7-1.3 pt.
Excellent
Labeled for permanent grass pastures, rangeland, non-crop lands, and CRP. New grass seedlings may be injured. Will injre legumes. Allow 6 to 8 hours between applications and rainfall. There are no grazing restrictions. Allow 7 days before transferring animals from treated pastures to sensitive crop pastures. Apply only once per 12 month period.
Clopyralid+2,4-D
Curtail
2-4 qt.
Excellent
Labeled for permanent grass pastures, rangeland, non-crop, and CRP. Will injure legumes. Do not graze lactating dairy cattle for 14 days. Animals should be removed from treated areas for 7 days before slaughter (not necessary if 12 weeds have passed since application). Allow 7 days before transferring animals from treated pastures to sensitive crop pastures. Do not cut for hay for 30 days after treatment.
Glyphosate
Many
2% solution
Good
See specific product's for details. Roundup Weathermax is labeled in pastures, rangeland, CRP, and non-crop areas. It is generally labeled for renovating, spot treatments, and rope wick applications. Will injure desired legumes and grasses. Spray foliage of musk thistle completely and uniformly, but not to the point of run off.
Metsulfuron Methyl
Ally/Cimmaron
0.2-0.3 oz.
Excellent
Labeled for grass pastures and rangeland. Grasses should be well establlished. May stunt, yellow, and suppress seed head formation in fescues and Timothy should be at least 6" tall. Tank mixing with 2,4-D may reduce injry to fescues. Ryegrass is highly sensitive. There are not grazing restrictions. Due to a long residual period, see label for rotation and reseeding restrictions.
Metsulfuron Methyl+Dicamba+2,4-D
Cimmaron Max
Co-pack 0.25 oz. part A + 1 pt. part B
Excellent
Labeled for grass pastures, rangeland, and established grasses in the CRP. Will injure legumes. Do not apply to Timothy for 12 months after establishment. Do not graze lactating animals for 7 days. Meat animals have to be removed from treated ares 30 days before slaughter. Do not harvest for dry hay for 37 days after treatment. Due to a long residual period, see label for rotation and reseeding restrictions.
Triclopyr+2,4-D
Crossbow
1.5% solutions or 4 qt.
Excellent
Labeled for perminant grass pastures, rangeland, CRP, and non-crop lands. Willl injure legumes. Do not graze dairy animals for 14 days. Remove meat animals from treated areas at least 3 days before slaughter.