Annual glyphosate treatments alter growth of unaffected bentgrass (Agrostis) weeds and plant community composition

Journal or Publishing Institution: PLoS One

Date of Publication: 12/04/2012

Study: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0050643

Author(s): Ahrens, C.W., Auer, C.A.

Article Type: Peer Reviewed Study

Abstract:

Herbicide resistance is becoming more common in weed ecotypes and crop species including turfgrasses, but current gaps in knowledge limit predictive ecological risk assessments and risk management plans. This project examined the effect of annual glyphosate applications on the vegetative growth and reproductive potential of two weedy bentgrasses, creeping bentgrass (CB) and redtop (RT), where the glyphosate resistance (GR) trait was mimicked by covering the bentgrass plants during glyphosate application. Five field plots were studied in habitats commonly inhabited by weedy bentgrasses including an agricultural hayfield, natural meadow, and wasteland. Results showed that annual glyphosate treatment improved bentgrass survivorship, vegetative growth, and reproductive potential compared with bentgrass in unsprayed subplots. In the second year of growth, RT plants had an 86-fold increase in flower number in glyphosate-treated subplots versus controls, while CB plants had a 20-fold increase. At the end of the three year study, plant community composition had changed in glyphosate-treated subplots in hayfield and meadow plots compared to controls. Soils in subplots receiving glyphosate had higher nitrate concentrations than controls. This is the first study to mimic the GR trait in bentgrass plants with the goal of quantifying bentgrass response to glyphosate selection pressure and understanding the impacts on surrounding plant communities.

Keywords: glyphosate, glyphosate resistance, bentgrasses, creeping bentgrass, red top, nitrate concentrations, pesticides, herbicides

Citation:

Ahrens, C.W., Auer, C.A., 2012. Annual Glyphosate Treatments Alter Growth of Unaffected Bentgrass (Agrostis) Weeds and Plant Community Composition. PLoS ONE, 7(12), e50643.

Category:

• Environmental effects
• Pesticide use

Record ID: 23