The role of climate change and increasing atmospheric carbon dioxide on weed management: Herbicide efficacy

Abstract

Rising concentrations of carbon dioxide [CO 2 ] and a changing climate will almost certainly 7 affect weed biology and demographics with consequences for crop productivity. The extent of such 8 consequences could be minimal if weed management, particularly the widespread and effective use of 9 herbicides, minimizes any future risk; but, such an outcome assumes that [CO 2 ] 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 [CO 2 ] 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 [CO 2 ] in the context of an uncertain and rapidly changing climate.

Invasive alien plant species: Their impact on environment, ecosystem services and human health

“…have invaded different Himalayan regions, which exacerbate the future climate change scenario, as predicted by the species distribution modelling (Shrestha et al, 2018). Climate change interactions with the IAPS are argued to have an increased invasion through complex intricate changes in IAPS physiognomy, anatomy and biochemistry (Ziska, 2016). Reduction in leaf protein levels of the IAPS under unpredictably changing climate can minimize effectiveness and persistence of herbicides in farmlands (Ziska, 2016).…”

“…Climate change interactions with the IAPS are argued to have an increased invasion through complex intricate changes in IAPS physiognomy, anatomy and biochemistry (Ziska, 2016). Reduction in leaf protein levels of the IAPS under unpredictably changing climate can minimize effectiveness and persistence of herbicides in farmlands (Ziska, 2016).…”

Climate Change and Pest Management: Unanticipated Consequences of Trophic Dislocation

“…In addition to evolutionary effects on weed competition, pesticide efficacy might also suffer with increasing temperatures. Ziska [56] has identified several pathways for herbicide efficacy to be reduced in response to elevated temperatures and CO 2 : morphological and physiological adaptation of weeds to increased temperatures and CO 2 could lead to increased weed vigor and fitness; persistence of herbicides on the crop could be reduced by elevated temperatures and increased frequency and/or severity of stormy weather would interfere with efficient pesticide application. These and other implications for weed management remain to be examined.…”

Indiana ’s Agriculture in a Changing Climate: A Report from the Indiana Climate Change Impacts Assessment

“…These species include Palmer amaranth, common waterhemp and redroot pigweed, which are significant problems in Indiana. Many weeds allocate increased amounts of carbon to tissues underground as CO 2 increases, making them more difficult to control with herbicides (Ziska 2016). Increased rain makes applying herbicides more difficult, too.…”