Do GE Hay Fields Affect Genetic Purity in Conventional Seed Fields?.

Alfalfa is an important livestock feed, especially for dairy production and horses. It was the first perennial crop genetically engineered (GE) to resist glyphosate herbicide and was available to farmers in 2011. In 2014, another GE trait, low-lignin stacked with glyphosate-resistant alfalfa was deregulated, and will be available sometime soon. Since alfalfa is predominantly insect-pollinated the potential for gene flow has been widely recognized. The US is a major exporter of alfalfa seed and hay and the organic dairy industry is one of the fastest growing agricultural sectors. In addition to meeting domestic needs, large amounts of alfalfa seed and hay produced in the US are being exported overseas. Due to cross-contamination of GE traits many alfalfa producers are impacted by market sensitivity. Our objective was to quantify the extent of transgene movement from GE hay fields to conventional seed fields and to define pollen dispersion curves based on the spatial distribution of commercial seed fields. Alfalfa seed and hay fields were mapped in Canyon/Owyhee County, ID. Canyon/Owhyee County has been designated an Adventitious Presence-Sensitive Grower Opportunity Zone where no GE alfalfa seed is produced. GE hay fields (source fields) and 5 conventional seed fields (sink fields), located at various distances from GE sources were identified in spring 2013. Sink fields were combine and hand harvested along field edges every 30 m. Original seed lot (seed used to plant the field in 2013) and overall harvested seed sample of the 2013 harvest were obtained for sink fields for baseline and overall AP assessment. Harvested seed samples were threshed, cleaned, scarified, and tested for the transgene using seedling germination assay. Distance from GE hay fields, pollinator abundance, elevation, aspect, and slope was also obtained. The relationship between AP proportion and distance to GE source fields will be modeled using nonlinear models. Pending completion of the analysis, further results will be presented.