1. University of Nebraska–Lincoln, Dept. of Agronomy and Horticulture, 402 W. State Farm Rd., North Platte, NE 69101, US
2. U.S. Dept. of Agriculture, Agricultural Research Service, Aerial Application Technology Research Unit, 3103 F&B Rd., College Station, TX 77845, US
3. University of Nebraska–Lincoln, Dept. of Biological Systems Engineering, Lincoln, NE 68583, US