1. College of Agriculture, California State University-Chico, Chico, CA, USA
2. Department of Genetics, “Luiz de Queiroz” College of Agriculture-ESALQ, University of São Paulo, Piracicaba, Brazil
3. USDA-ARS, Soil Management and Sugar Beet Research, Fort Collins, CO, USA
4. Department of Horticulture & Landscape Architecture, Center for Root and Rhizosphere Biology, Colorado State University, Fort Collins, CO, USA