|Benech Arnold, Roberto|
Submitted to: North Central Weed Science Society US Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 12/14/2001
Publication Date: 12/14/2001
Citation: SCURSONI, J., PETERSON, D.H., FORCELLA, F., GUNSOLUS, J., BENECH ARNOLD, R., OWEN, M., SMEDA, R., OLIVER, D., VIDRINE, R. WEED DIVERSITY IN GLYPHOSATE-TOLERANT SOYBEAN FROM MINNESOTA TO LOUISIANA. NORTH CENTRAL WEED SCIENCE SOCIETY U S PROCEEDINGS. 2001. V. 56. P. 105. Interpretive Summary:
Technical Abstract: In Europe, especially, glyphosate-tolerant crop technology has elicited great concern. Some of this concern involves the perception that this new technology kills weeds so thoroughly that biodiversity will decrease relative to traditional forms for weed management. The concern with biodiversity involves not only weeds, but also animals and microbes that depend upon weeds for food and cover. Our objectives were to examine trends in weed diversity (alpha, beta, and gamma diversity) along an environmental/longitudinal transect from Minnesota (5 sites), Iowa (3 sites), Missouri (2 sites), Arkansas (2 sites) to Louisiana (1 site); and a gradient of management intensity at each site that included the following treatments in glyphosate-tolerant soybean: (a) weedy check, (b) one-pass standard PRE plus standard POST, or standard POST only. Preliminary analyses of effective species richness (e**H') indicate that rankings of weed diversity across treatments did not change substanitally among locations. Diversity in the one-pass glyphosate treatment often was higher than that of weedy checks because the herbicide differentially suppressed dominant weed diversities. Diversity in the two-pass glyphosate treatment typically was low: near zero in the North and substantially higher than zero in the South, but still usually lower than standard herbicide treatments. Bearing in mind that our data merit much more rigorous analyses, tentative results suggest that the impacts of glyphosate-tolerant crop technology on biodiversity will vary according to latitude and the number of glyphosate applications made in the soybean crop.