Temperature and CO2 are two of the main environmental factors associated with climate change. It is generally expected that elevated [CO2] will increase crop production. However, other environmental factors such as temperature along with management practices could further modify a crop’s response to CO2. The goal of this study was to determine the interactive effects of elevated [CO2] and aboveoptimum temperature on growth, development and yield of two peanut (Arachis hypogaea L.) cultivars, e.g., Pronto and Georgia Green. One of the objectives was to determine if there was any variation in response between these two cultivars with respect to possible adaptation to climate change. Peanut plants were grown in controlled environment chambers in the University of Georgia Envirotron under conditions of non-limiting water and nutrient supply. Plants were exposed to day/night air temperatures of 33/21◦C (TA), 35.5/23.5◦C (TA + 2.5◦C), and 38/26◦C (TA + 5◦C) along with CO2 treatments of 400 and 700 μmol CO2 mol−1 air. The selected range of temperatures was based on the temperatures that are common for southwest Georgia during the summer months. The results showed that LAI of both cultivars responded positively, e.g., 28.3% for Pronto and 49.3% for Georgia Green to elevated [CO2]. Overall, elevated [CO2] alone resulted in a significant increase in total biomass at final harvest across all temperatures (P < 0.0001), but decreased final seed yield (P < 0.0005), except for Georgia Green at (TA + 5◦C). The higher temperatures compared to TA reduced the relative response of total biomass to CO2 for both cultivars. It can be concluded that final seed yield response to CO2 depends on the sensitivity of individual cultivars to temperature, especially during the reproductive development stage.

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