The National Agricultural Statistics Service (NASS) conducted the 2012 Agricultural Chemical Use Survey among wheat producers in 15 states: Colorado, Idaho, Illinois, Kansas, Minnesota, Missouri, Montana, Nebraska, North Dakota, Ohio, Oklahoma, Oregon, South Dakota, Texas, and Washington.
The 13 winter wheat program states accounted for 80% of the acreage planted in the U.S. in the 2012 crop year. The data are based on 1,371 individual questionnaires. The four spring wheat (excl. durum) program states accounted for 91% of the U.S. planted acreage in 2012. The data are based on 422 individual questionnaires. The two durum wheat program states accounted for 88% of the planted acreage in 2012, and the data are based on 214 questionnaires.
Nitrogen was the most widely used fertilizer material on wheat planted acres, applied to nearly all durum and spring (excl. durum) wheat acres and 85% of winter wheat acres. Phosphate (P2O5) and potash (K2O) were the next most widely applied fertilizer materials. Nitrogen was applied to spring (excl. durum) wheat at an average rate of 84 pounds per acre for the 2012 crop year. Average nitrogen rates for durum and winter wheat were 70 and 62 pounds per acre, respectively.
The pesticide active ingredients used on wheat are classified in this report as herbicides, insecticides or fungicides. Herbicides were the most extensively used, applied to nearly all durum and spring (excl. durum), and 61% of winter, wheat planted acres. Fungicides were applied to 49% of spring (excl. durum), 39% of durum, and 19% of winter wheat acres. Insecticides were used less extensively across all three wheat types. The specific herbicides applied varied across wheat types.
The survey asked growers to report on the pest management practices they used on wheat. Pests are defined as weeds, insects or diseases.
Wheat growers reported practices in four categories of pest management strategy:
- Prevention practices keep a pest population from infesting a crop or field through various preceding actions.
- Avoidance practices mitigate or eliminate the detrimental effects of pests through cultural measures.
- Monitoring practices involve observing or detecting pests through systematic sampling, counting, or other forms of scouting.
- Suppression involves controlling or reducing existing pest populations to mitigate crop damage.
Scouting for weeds was the most widely reported monitoring practice in 2012, used on 86%, 97% and 99%, respectively, of winter, spring (excl. durum), and durum wheat planted acres. In the wheat chemical use survey conducted in 2009, scouting for weeds was also a commonly reported monitoring practice for all three wheat types.
Among prevention practices, no-tillage or minimum tillage was the top reported practice in both the 2012 and 2009 chemical use surveys. Among avoidance practices, crop rotation was the top reported practice, although percentages varied across wheat types. The most reported suppression practice was maintaining ground covers, mulches or other physical barriers.