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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Dairy Forage Research » Research » Publications at this Location » Publication #244466
Title: Review of Roundup Ready Alfalfa

Author
item UNDERSANDER, DAN - University Of Wisconsin
item Martin, Neal
item HALL, MARVIN - Pennsylvania State University
item MUELLER, SHANNON - University Of California

Submitted to: Forage and Grazinglands
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/28/2009
Publication Date: 10/19/2009
Citation: Undersander, D.J., Martin, N.P., Hall, M.H., Mueller, S.C. 2009. Review of Roundup Ready Alfalfa. Forage and Grazinglands. Available: http://www.plantmanagementnetwork.org/sub/fg/review/2009/alfalfa/

Interpretive Summary: Roundup Ready (RR) alfalfa is the first forage species commercially released with a genetically modified trait. RR alfalfa is able to withstand glyphosate (Roundup), one of the environmentally safest herbicides in the farmer’s arsenal to control weeds, so that farmers may apply it to kill weeds without killing the alfalfa. While not needed by all farmers who grow alfalfa, RR alfalfa may allow some farmers to more effectively establish alfalfa and control certain weed problems. But the potential for gene flow (from genetically modified to conventional alfalfa crops) is a concern in alfalfa seed and forage production systems because approximately 30% of alfalfa seed produced in the U.S. is sold in countries not allowing crops from genetically modified organisms (GMOs), and some markets within the U.S. require GMO-free seed. Unresolved issues over gene flow resulted in RR alfalfa seed sales being enjoined in 2006 pending completion of an Environmental Impact Assessment by USDA to address the potential of gene flow to non RR alfalfa seed and forage fields. Our review of the literature on this topic shows that, with proper isolation distances and management practices, conventional and organic production can be protected from RR alfalfa in order to maintain existing domestic and export markets that may be sensitive to GMOs. The literature also shows that it is crucial that farmers use appropriate stewardship practices to minimize weed shifts and/or an increase in glyphosate resistant weeds in agricultural systems. Also, the commercialization of other GMO traits in alfalfa (such as reduced lignin for increased digestibility, high bypass protein, and increased disease and insect resistances) are dependent on the success of RR alfalfa. Since the commitment to research is less for alfalfa than many grain crops, market failure of this trait will increase the cost of future biotech efforts with alfalfa and likely eliminate the use of this technology in alfalfa improvement efforts. This review will help those in the alfalfa industry, and also policy makers, understand the benefits of using RR alfalfa and how concerns of gene flow have been addressed by the alfalfa industry.

Technical Abstract: Roundup Ready (RR) alfalfa is the first forage species commercially released with a genetically modified trait. While not needed by all farmers who grow alfalfa, RR alfalfa may allow some farmers to more effectively establish alfalfa and control certain weed problems. Gene flow potential in alfalfa seed and forage production systems is a concern because approximately 30 % of alfalfa seed produced in U.S.A. is sold in countries not allowing GMO crops and some markets within U.S.A. require GMO-free seed. Unresolved issues over gene flow between GE and conventional alfalfa fields resulted in RR alfalfa seed sales being enjoined in 2006 pending completion of an environmental Impact Assessment by USDA addressing potential gene flow to non RR alfalfa seed and forage fields. Glyphosate is one of the environmentally safest herbicides in the farmer’s arsenal to control weeds. Roundup Ready alfalfa provides some farmers with another tool to increase the efficiency of crop production, however it will not be used by farmers who use a nurse crop or who mix grass with the alfalfa at seeding. With proper isolation distances and management practices, conventional and organic production can be protected in order to maintain existing domestic and export markets that may be sensitive to GE. It is crucial that farmers use appropriate stewardship practices to minimize weed shifts and/or an increase in glyphosate resistant weeds in agricultural systems. The commercialization of other GMO traits in alfalfa, such as low lignin for increased digestibility, high bypass protein, and increased disease and insect resistances are dependent on the success of RR alfalfa. Since the commitment to research is less for alfalfa than many grain crops, market failure of this trait will increase the cost of future biotech efforts with alfalfa and likely eliminate the use of this technology in alfalfa improvement efforts.