Files
Abstract
Climate change is a pressing global concern with far-reaching consequences, including its impact on ecosystems and agriculture. Rising temperatures, elevated carbon dioxide (CO2) levels, and various stressors pose long-term threats to individual plants, plant communities, and entire ecosystems. In agricultural settings, climate change can disrupt food production, availability, and accessibility, with weed management facing new challenges due to shifting dynamics and the emergence of herbicide-resistant weeds.This study focuses on Palmer amaranth, a notorious weed in the US and worldwide, to investigate its growth and response to climate change conditions. We assessed the impact of elevated CO2 and temperature levels on Palmer amaranth biotypes, both glyphosate-susceptible (GA2005) and glyphosate-resistant (GA2017), over multiple growth seasons. Our findings suggest that susceptible biotypes may outcompete others in environments without herbicide pressures, but caution is warranted when generalizing these results to field conditions.
Notably, this research demonstrates that CO2 levels had a more pronounced effect on Palmer amaranth growth than temperature, challenging previous assumptions about C4 plants' limited response to elevated CO2. The study also highlights the importance of deeper physiological investigations to understand the underlying mechanisms of observed changes.
Furthermore, we examined the absorption, translocation, and composition of epicuticular waxes in response to glyphosate under current and elevated CO2 and temperature levels. Surprisingly, all biotypes exposed to higher CO2 and temperature exhibited increased glyphosate absorption, with the susceptible biotype showing substantial movement above the treated leaf. The presence of polar compounds in epicuticular waxes, more prevalent under raised CO2 and temperature, may facilitate herbicide absorption.
This research underscores the intricate interplay between climate change, agriculture, and herbicide-resistant weeds. Palmer amaranth's adaptability and genetic diversity present significant challenges for studying its growth, emphasizing the need for comprehensive research. Understanding how this weed responds to climate change is essential for developing effective and sustainable weed management strategies. Moreover, the study serves as a foundation for investigating how other plant species adapt to changing climates, contributing to broader ecological and agricultural insights.