1. Dep. of Plant Science Univ. of Manitoba 222 Agriculture Building, 66 Dafoe Road Winnipeg MB R2T 2N2 Canada
2. Dep. of Soil Science Univ. of Manitoba 362 Ellis Building, 13 Freedman Cresent Winnipeg MB R3T 2N2 Canada
3. Northwest Research and Outreach Center 2900 University Ave Crookston MN 56716 USA