COMPARISON OF THE ECO-EFFICIENCY OF CONVENTIONAL AND GLYPHOSATE-RESISTANT SUGARBEET PRODUCTION. Andrew R. Kniss, Carl W. Coburn*; University of Wyoming, Laramie, WY (131)
The rapid adoption of glyphosate-resistant sugarbeets has largely displaced conventional sugarbeet production. Eco-efficiency analysis allows the comparison of production systems by quantifying the level of output per unit of input. A study was conducted to compare the eco-efficiency of herbicide treatments in conventional and glyphosate-resistant sugarbeet production. Using herbicide environmental impact and yield data from six studies located in multiple growing regions in the U.S., a partial eco-efficiency analysis was performed on conventional and glyphosate-resistant systems. Greater values of eco-efficiency lower environmental impact per unit of sugar production. The average eco-efficiency of all glyphosate treatments was 16% less than the average of all conventional treatments including micro-rates (P=0.066). Micro-rate treatments of conventional herbicides resulted in an eco-efficiency value 1.5 and 1.4 times greater than the average of all glyphosate and conventional treatments, respectively (P=0.046 and P=0.017). Micro-rate treatments provided the maximum eco-efficiency in each study. Inclusion of a preemergence herbicide in conventional and micro-rate treatments reduced eco-efficiency values below that of glyphosate treatments. Future comparisons will include additional herbicide studies, as well as compare tillage and other inputs that differ between conventional and glyphosate-resistant sugarbeet production systems.