Scouting and keeping good weed records are just one of the ways to manage weed resistance in your fields
by PAT LYNCH
There are at least four known ways that weeds develop resistance to glyphosate. They do it by mutations where genes mutate to deal with glyphosate. One of these methods is called exclusion. In this system, the glyphosate is controlled in the vacuole of the cell plant and not allowed to translocate through the rest of the plant.
This system is temperature related. It is the system found in glyphosate-resistant Canada Fleabane. Interesting that in the United States, when this fleabane is sprayed at temperatures above 23 C, it escapes. When sprayed with glyphosate at temperatures below 8 C, it is controlled.