Exotic C4 grasses have increased tolerance to glyphosate under elevated carbon dioxide.

Anthony Manea, Michelle Leishman, Paul Downey

Research output: Contribution to journalArticlepeer-review

49 Citations (Scopus)


The increase in atmospheric CO2 levels can influence the growth of many invasive exotic plant species. However, it is not well-documented, especially for C4 plants, how these growth responses will alter the effectiveness of the worldâ¿¿s most widely used herbicide for weed control, glyphosate. We aimed to address this question by carrying out a series of glasshouse experiments to determine if tolerance to glyphosate is increased in four C4 invasive exotic grasses grown under elevated CO2 in nonlimiting water conditions. In addition, traits including specific leaf area, leaf weight ratio, leaf area ratio, root : shoot ratio, total leaf area, and total biomass were measured in order to assess their contribution to glyphosate response under ambient and elevated CO2 levels. Three of the four mature grass species that were treated with the recommended concentration of glyphosate displayed increased tolerance to glyphosate under elevated CO2. This was due to increased biomass production resulting in a dilution effect on the glyphosate within the plant. From this study, we can conclude that as atmospheric CO2 levels increase, application rates of glyphosate might need to be increased to counteract the growth stimulation of invasive exotic plants.
Original languageEnglish
Pages (from-to)28-36
Number of pages9
JournalWeed Science
Issue number1
Publication statusPublished - 2011
Externally publishedYes


Dive into the research topics of 'Exotic C4 grasses have increased tolerance to glyphosate under elevated carbon dioxide.'. Together they form a unique fingerprint.

Cite this