If tillage alone is used to terminate the alfalfa stand, it must be aggressive enough to sheer roots. Often aggressive tillage is not an option for highly erodible soils.
Herbicides need to be applied before a killing freeze and when there is sufficient alfalfa growth (generally 4 to 6 inches). Ideally, temperatures for a few days following the application should be above 50°. Often the combination of an herbicide application followed by tillage a week or more later provides the best control. Herbicide selection will be dictated by the composition of the stand. Though growth-regulating herbicides such as 2,4-D and dicamba in combination are very effective for terminating alfalfa, they won't kill perennial grass species. This is when glyphosate must be added to the mixture. As mentioned earlier, glyphosate alone often does not do an effective job of completely killing alfalfa. Of course, glyphosate will be totally ineffective on Roundup Ready alfalfa.
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