1. USDA ARS, Grain Marketing and Production Research Center, Engineering Research Unit, Manhattan, KS 66502. Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by the USDA implies no approval of the product to the exclusion of others that may also be suitable.
2. Corresponding author. Phone: 785-776-2753. Fax: 785-537-5550. E-mail: floyd.dowell@gmprc.ksu.edu
3. USDA ARS, Lincoln, NE.
4. University of Nebraska, Lincoln, NE.
5. University of Nebraska Panhandle Research and Extension Center, Scottsbluff, NE.