|RUIZ-VERA, URSULA - University Of Illinois|
|SIEBERS, MATTHEW - University Of Illinois|
|JAISWAL, D - University Of Illinois|
|ORT, DONALD - University Of Illinois|
Submitted to: Plant, Cell & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/12/2018
Publication Date: 11/18/2018
Citation: Ruiz-Vera, U.M., Siebers, M.H., Jaiswal, D., Ort, D.R., Bernacchi, C.J. 2018. Canopy warming accelerates development in soybean and maize, offsetting the delay in soybean reproductive development by elevated CO2 concentrations. Plant, Cell & Environment. 41:2806-2820. https://doi.org/10.1111/pce.13410.
Interpretive Summary: Crop development is generally categorized into discreet developmental stages that represent the progression from emergence to reproduction, to eventual senescence. The rate of development, and in particular the amount of time that a plant will stay within a given developmental stage, is highly dependent on environmental conditions. Because the atmosphere and the climate is changing at a rapid rate, there is uncertainty regarding how warming temperatures and rising CO2 will impact rates of development. This experiment measured developmental stages of soybean grown under field conditions exposed to either normal growing conditions, warmer temperatures through infrared heating, higher than normal atmospheric CO2 through Free Air CO2 Enrichment techniques, or to combined warming and higher CO2. The results show that development was faster in the plants grown at higher temperature, but that CO2 itself had no effect. The results of this work can help to inform models to better represent changing developmental rates in response to increasing climate variability.
Technical Abstract: Increases in atmospheric CO2 concentrations ([CO2]) and surface temperature are known to individually have effects on crop development and yield but their interactive effects, which is most relevant to predicting impacts of global change have not been adequately investigated under field conditions. We evaluated the impacts of elevated [CO2] with and without canopy warming as a function of development in soybean and maize. We used infrared heating arrays nested within Free Air CO2 enrichment plots over three growing seasons. We found an acceleration of vegetative development in soybean with temperature plus elevated [CO2] resulting in higher node number. Reproductive development was delayed in soybean under elevated [CO2] but warming mitigated this delay. In maize, both vegetative and reproductive development were accelerated by warming whereas elevated [CO2] had no apparent effect on development. There were treatment-induced changes in the leaf carbohydrates, dark respiration rate, morphological parameters and environmental conditions that accompanied changes in plant development. Warming increased the growing degree-days threshold to reach each developmental stage, an effect which is not currently incorporated in the parametrization of the growing degree day model for warmer climates.