found pesiticide residues in 90 of 96 cereal crop samples tested. However, it concluded that "None of the residues detected by the laboratory would be expected to have an effect on health."
Glyphosate is sometimes used as a desiccant to alter the timing of wheat harvests, ensure even ripening, and to make harvesting easier. While it's not a widespread practice, it does happen in the US.
Actually, it's a relatively popular harvesting practice for non-organic crops -- kill them all at the same time so they're all ready to harvest. Differs by region, but afaik in the US foods labelled as organic can't be harvested in this way.