1. Dep. of Agronomy & HorticultureUniv. of Nebraska-LincolnNorth PlatteNE69101
2. Dep. of Plant and Soil SciencesMississippi State Univ.Mississippi StateMS39762
3. Dep. of Plant SciencesNorth Dakota State Univ.FargoND58108
4. USDA-ARS Aerial Application Technology Research UnitCollege StationTX77845
5. Dep. of Biological Systems EngineeringUniv. of NebraskaLincolnNE68583