1. Department of Agricultural, Food and Nutritional Science; University of Alberta, 410 Agriculture/Forestry Centre; Edmonton Alberta T6G 2P5 Canada
2. Biology Department; Rhode Island College, 251 Fogarty Life Science Building; Providence RI 02908 U.S.A.
3. Tannas Conservation Services, Box 31; Cremona Alberta T0M 0R0 Canada
4. Lethbridge Research Center; Agriculture and Agri-Food Canada, 5403 1st Avenue South; Lethbridge Alberta T1J 4P4 Canada