Author
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Ziska, Lewis |
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Submitted to: Agriculture, Ecosystems and Environment
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/20/2016 Publication Date: 9/2/2016 Citation: Ziska, L.H. 2016. The role of climate change and increasing atmospheric carbon dioxide on weed management: Herbicide Efficacy. Agriculture, Ecosystems and Environment. 231: 304-309. Interpretive Summary: Rising concentrations of carbon dioxide [CO2] and a changing climate will affect where and how agricultural weeds grow and their overall impact on crop production. The extent of any projected damage will depend, in large part, on the effectiveness of herbicides, chemicals that are used to kill weeds. However it is unclear if this effectiveness, in turn, will also be affected by climate and/or changes in [CO2]. While additional data are greatly desired, there is sufficient information currently available to begin an initial assessment of how climate change and/or [CO2] will affect herbicide effectiveness before, during and following herbicide application. The assessment provided here, while preliminary, reviews a number of physical and biological interactions that are likely, overall, to significantly reduce herbicide effectiveness. These interactions can range from climatic extremes that influence spray coverage and field access to direct effects of [CO2] or temperature on plant biochemistry and morphology. Identification of these mechanisms will be essential to both understand and strengthen herbicide management in the context of rising levels of [CO2] and an uncertain and rapidly changing climate. This information will be of value to farmers, land managers, pesticide applicators, scientists, NGOs and business. Technical Abstract: Rising concentrations of carbon dioxide [CO2] and a changing climate will almost certainly affect weed biology and demographics with consequences for crop productivity. The extent of such consequences could be minimal if weed management, particularly the widespread and effective use of herbicides, minimizes any future risk; but, such an outcome assumes that [CO2] or climate change will not affect herbicide efficacy per se. Is this a fair assumption? While additional data are greatly desired, there is sufficient information currently available to begin an initial assessment of both the physical and biological constraints likely to occur before, during and following herbicide application. The assessment provided here, while preliminary, reviews a number of physical and biological interactions that are likely, overall, to significantly reduce herbicide efficacy. These interactions can range from climatic extremes that influence spray coverage and field access to direct effects of [CO2] or temperature on plant biochemistry and morphology. Identification of these mechanisms will be essential to both understand and strengthen weed management strategies associated with rising levels of [CO2] in the context of an uncertain and rapidly changing climate. |
