Practices that Support Coexistence: A Survey of Alfalfa Growers

Abstract

The alfalfa industry has worked hard to foster the coexistence of genetically engineered and conventional alfalfa production by developing a set of best management practices that aim to limit adventitious presence (AP) of genetically engineered traits in conventional seed. The general goal is to minimize transgene movement by controlling inadvertent admixture (in this case admixture refers to genetically engineered material in conventional seed lot) or gene flow using practices that ensure seed is pure, sanitation is prioritized (i.e., avoidance of seed mixing), spillage is minimized, and pollination is prevented. However, the success of coexistence is dependent on grower adoption, which has not been monitored. To assess adoption we surveyed 530 alfalfa hay and seed producers in three major alfalfa production areas in the western United States in 2013. Based on a 33% response rate, we found that although many respondents reported practices that supported coexistence, the survey identified differences in grower perception and practices in the three states surveyed and identified perceptions and practices that may undermine coexistence. We found that very few respondents (4%) tested hay seed prior to planting, and no respondents in Washington reported testing seed despite reporting the highest level of export. Growers also underestimated the risk of seed spillage during planting and seed harvest and transport. Most respondents controlled feral plants, but control was limited to their own property. Some respondents were using glyphosate to control volunteers and roadside plants. Management of hay fields also varied in terms of cutting time, frequency of delayed cutting, and occurrence of field obstructions that prevented cutting. Our survey suggested that grower education would benefit coexistence, as would research to better understand the potential of genetically engineered hay fields to contribute to economically adverse AP.