George B. Frisvold
University of Arizona
Terrance M. Hurley
University of Minnesota
Paul D. Mitchell
University of Wisconsin

Weeds, along with insect pests and plant diseases, are sources of biotic stress in crop systems that reduce yields, raise production costs, and contribute to income risk to farmers (HarvestChoice, 2009). Transgenic, herbicide- resistant (HR) crop varieties, first introduced in 1996, offer the promise of more effective weed control. By 2008, more than 79 million hectares worldwide were planted to HR varieties of soybean, maize, canola, cotton, alfalfa, and sugar beets (James, 2009). Read More . . .