1. Department of Biological Sciences, University of Lethbridge, 4401 University Dr., Lethbridge, AB T1K 3M4, Canada.
2. Agriculture and Agri-Food Canada, Lethbridge Research & Development Centre, 5403 1st Ave. S., Lethbridge, AB T1J 4B1, Canada.
3. Department of Economics, University of Lethbridge, 4401 University Dr., Lethbridge, AB T1K 3M4, Canada.
4. Alberta Agriculture and Forestry, Crop Diversification Centre South, 301 Horticultural Station Rd. E., Brooks, AB T1R 1E6, Canada.