Monitoring freeze injury potential to U.S. winter wheat during dormancy

U.S. winter wheat, grown primarily across the Plains, Midwest, and Northwest, is an exceptionally hardy crop. Planted in the fall, winter wheat becomes vegetatively established--exhibiting root and leaf development--before daily average temperatures fall below 40 degrees F. Winter wheat is most resistant to freeze injury during the winter months, a period of crop dormancy in much of the U.S. Wheat that has become well established and undergone sufficient cold hardening prior to dormancy can withstand temperatures as low as -5 to -10 degrees F without sustaining significant injury. Even lower temperatures are not harmful as long as winter wheat is blanketed with a protective snow cover. Therefore, it is useful to monitor potential freeze injury to the winter wheat crop using temperature and snow depth observations provided by the U.S. Cooperative Observer Network, managed and maintained by the National Oceanic and Atmospheric Administration (NOAA) of the U.S. Department of Commerce (DOC). Monitoring of winter wheat freeze injury potential and many other crop-weather assessments are provided by the Joint Agricultural Weather Facility (JAWF), jointly operated by DOC/NOAA and the U.S. Department of Agriculture's Office of the Chief Economist (USDA/OCE). Such assessments are conveyed to a broad audience in the Weekly Weather and Crop Bulletin, JAWF's flagship publication.