1. Dep. of Crop, Soil, and Environmental SciencesUniv. of Arkansas 1366 W. Altheimer Drive Fayetteville AR 72704
2. Univ. of SaskatchewanDep. of Plant Sciences 51 Campus Drive Saskatoon SK 5A8 S7N Canada
3. Dep. of Biological and Agricultural EngineeringUniv. of Arkansas, Northeast Research and Extension Center P.O. Box 48 Keiser AR 72351