Banvel, Roundup, Tordon, 2,4-D, Curtail, and Stinger are herbicides that have the greatest activity on Canada thistle. Highest rates should be used without interfering with next years cropping pattern. Situations may occur where spot treatment with herbicides at high rates may be viewed as the best Canada thistle management program even if the carryover may injure next year's crop. Timing is a critical factor. Herbicide application after a frost at 32 degrees F may enhance control but application in late October when leaf tissue was destroyed by frost may result in less control due to lack of herbicide uptake.
Tillage can be a critical factor.
If lower herbicide rates or less effective herbicides are used, tillage is very important. If tillage is not planned then use the most effective herbicide or tank-mix at higher rates. Spray rosettes of actively growing plants. The EU pays farmers a support payment, called an area payment, on top of high internal prices. World wheat production has been forecast at 591 million tonnes in 1998, the second-largest world crop on record.