To expand on the answer to your question, glyphosate is used in the production of wheat in the U.S., however, its use is limited. In the majority of U.S. wheat fields, it isn’t used at all. In fact, for 2016, it was applied to only 33 percent of wheat acres in the U.S., according to an independent consumer research firm, GfK. Of this 33 percent, nearly all of the acres have glyphosate applied when a harvestable wheat crop is not present, either in fallow or no-till cropping systems prior to planting.
Another labeled, authorized use of glyphosate that growers have at their disposal is to apply to the crop prior to harvest. The U.S. Environmental Protection Agency (EPA), which regulates all pesticides including herbicides like glyphosate, refers to this use as a “pre-harvest’ treatment. Pre-harvest applications occur on very few of wheat acres in the U.S. These applications are made after the wheat plant has shut down, wheat kernel development is complete and the crop has matured. Therefore, the wheat plant is not taking up the glyphosate, but the green weeds in the fields will be killed by the glyphosate to enhance the efficiency of harvest. Published research has demonstrated that when glyphosate is applied to wheat just prior to harvest in accordance with Environmental Protection Agency (EPA) approved label directions and recommendations from university extension publications, plant uptake is minimal. The amount of glyphosate on the harvested wheat was well below EPA-approved levels—approximately 1% of those levels.
In spite of this EPA approved pre-harvest treatment, Montana growers rarely have a need to use it because of the low rainfall experienced during the growing season. Low rainfall reduces weed growth and the necessity to manage them prior to harvest.
Based on the “use” information for glyphosate in wheat, there is a very high probability that wheat sourced from producers in Montana is free from glyphosate residue in the grain.