Farmers in Kansas, Oklahoma, Colorado and Texas are hoping for relief this week from persistent drought conditions that threaten yields in many of the United States most productive winter wheat growing areas. Lack of rainfall since late October along with extremely low topsoil moisture conditions are heightening concerns about lost yield potential and abandonment of winter wheat acres in key states. Depending on temperatures and location, the U.S. winter wheat crop normally breaks from dormancy in late February or early- to mid-March. Rainfall is needed either before the dormancy period ends or shortly after to avoid significant yield losses