Risk Assessment for Biotech Alfalfa

In the future, alfalfa growers will have new biotech alfalfa varieties to choose from. New information and recommendations to growers from an Agricultural Research Service study can help prevent accidental dispersion of biotech pollen to volunteer alfalfa plants.

Pollen can carry genetically engineered genes to wild alfalfa plants that just appear in or near a field of planted crops or into a related species. That’s why ARS plant geneticist Daniel Z. Skinner and other ARS researchers conducted a 3-year biorisk assessment of mock transgenic alfalfa.

Alfalfa is pollinated by honey bees and leaf-cutter bees. A key factor in setting isolation requirements for seed production is the amount of potential pollen flow between adjacent alfalfa seed production fields.

Using a molecular marker found in alfalfa, Skinner and research associate Paul St. Amand tracked alfalfa pollen movement from seed and hay fields. Leafcutter bees, used in commercial seed production, fly directly from their hives for a distance of more than a half mile and back home. Because a minimum isolation distance of 5,109 feet from the hive may be required to prevent gene flow in alfalfa, Skinner says that producers would want to consider changing their seed production practices.

Bee hives need to be placed in the center, instead of along the side of the alfalfa field. Also, planting flowering crops like birdsfoot trefoil or sainfoin may get the bees to stop at the border of the field.

A full report on this work can be found in the Octoberissue of Agricultural Research magazine, ARS’ monthly publication.

ARS is the U.S. Department of Agriculture's chief scientific research agency. Skinner is based in Pullman, Wash., at the ARS Wheat Genetics, Quality, Physiology and Disease Research Unit.