This blog is the third in a five part series, titled “The Truth About Glyphosate,” sharing the facts about glyphosate and its use in the wheat industry.
Our country has the safest, most abundant food supply in the world. Other countries rely on the U.S. to set safety standards that impact people globally. Wheat growers raise their crops with care to ensure it is as safe for families everywhere as it is for their own.
As discussed in a previous blog, herbicides are one tool for any grower to manage weeds in any crop and produce the best quality product possible in any given year. U.S. wheat growers are no exception. After mandatory pesticide training to obtain an applicators license, wheat growers follow EPA approved label directions when applying any type of crop protection material.
The USDA surveys U.S. wheat growers about their agronomic practices including the use of herbicides such as glyphosate. USDA conducts personal interviews with growers across the country to understand which pesticides are used in wheat production. The examination of pesticide use trends is their objective and is critical for an informed pesticide policy debate and science-based decisions. These surveys have been done in 2000, 2004, 2006, 2009 and 2012. In 2009, 3,699 farms were chosen at random from a list of farms reporting wheat plantings to USDA. Data were collected for a single field at each farm rather than the farm as a whole.
The USDA is interested in pesticide use trends. Their surveys are designed to understand which pesticides are used to produce a given crop and how much pesticide is applied. They are not designed to understand how or when the pesticide is applied. The main difference between USDA’s National Ag Statistical Service (NASS) collected data for wheat and other sources of pesticide use survey data is the inclusion of application timing. GfK, an independent consumer research firm, asks when the application was made. This is critical in order to distinguish applications to a crop from applications made before a crop is planted or following the harvest of the crop. Applications made when the wheat crop is not present are meant to control weeds during fallow periods to prevent weeds from using valuable moisture in semi-arid regions of wheat production.
In wheat, glyphosate use is limited to a pre-harvest application. The use of pre-harvest applications has declined over time and is currently below 2 percent of total acres. Cessna et al. (1994) examined levels of glyphosate in harvested wheat treated with glyphosate at different rates and at different times near harvest as grain moisture levels declined. There was no indication that any of the application rates or timings would result in glyphosate residue levels greater than the EPA approved tolerance. These results are supported by data on glyphosate residues in cereal crops collected in the EU where pre-harvest uses of glyphosate are also allowed.
Taken together, the available data and information demonstrate that pre-harvest applications of glyphosate are not a common occurrence in U.S. wheat crops, and current application timings have little potential to result in glyphosate being present on harvested grain.
Bottom line: The U.S. food supply is safe. Using available technology to provide an abundant, safe, high-quality food supply is essential to meeting the demands of a growing world population. Remember, if you have questions about how your food is raised, ask the expert; ask a farmer.