1. Assistant Professor, Dept. of Plant and Soil Science, Texas Tech Univ., P.O. Box 42122, Lubbock, TX 79409; formerly, Postdoctoral Fellow, Dept. of Plant and Environmental Sciences, New Mexico State Univ., MSC 3Q, P.O. Box 30003, Las Cruces, NM 88003 (corresponding author).
2. Statistical Programmer, PVR Technologies, King of Prussia, PA 19406; formerly, Graduate Research Assistant, Dept. of Plant and Environmental Sciences, New Mexico State Univ., Las Cruces, NM 88003.
3. Professor, Dept. of Plant and Environmental Sciences, New Mexico State Univ., Las Cruces, NM 88003.
4. Field Scientist, DOW AgroSciences Canada Inc., London, ON N6H4Z8; formerly, Associate Professor, Dept. of Extension Plant Sciences, New Mexico State Univ., Las Cruces, NM 88003.
5. Professor, Dept. of Environmental Sciences, Univ. of California, Riverside, CA 92521.