David J. Pannell
University of Western Australia
Pascal Tillie and Emilio Rodríguez-Cerezo
European Commission, Institute for Prospective Technological Studies (IPTS), Joint Research Center (JRC)
David Ervin
Portland State University
George B. Frisvold
University of Arizona

This article presents comparative perspectives from Australia, the European Union, and the United States from a plenary session, “Herbicide resistance: Challenges for Farmers and Implications for the Environment” at the 19^th Annual Conference of the International Consortium on Applied Bioeconomy Research. Herbicide- resistant (HR) weeds threaten the sustainability of herbicidetolerant (HT) crops, pose environmental risks from alternative weed control methods, and are altering public and private research and development programs. Institutional responses to HR weeds across the three regions, while confronting similar problems (in some respects, but not others), are taking different forms. The article discusses public policies and private-sector strategies to address weed resistance problems. Considerations of HR weeds are already transforming regulatory approval processes for new HT crop varieties. We conclude by discussing over-arching public policy and agricultural research challenges.

Key words: Australia, biotechnology, economics, European Union, herbicide-resistant crops, herbicide-resistant weeds, integrated weed management, regulation, United States, weed seed control.