Climate Change and Potato: Effects of Carbon Dioxide, Temperature, and Drought On Gas Exchange and Growth.

Potatoes are the fifth largest produced crop in the world according to 2010 Food and Agriculture Organization of the United Nations (FAOSTAT) statistics. As with most other plants that use the C3 carbon fixation pathway, potato generally exhibits positive responses to increases in atmospheric carbon dioxide concentration (CO2). Under non-limiting nutrient and water conditions, higher photosynthetic rates, dry matter production, water use efficiency, and reduced transpiration have been observed. Despite its agronomic importance, however, considerably less is known about how temperature or varying degrees of soil water availability influence potato responses under elevated CO2 conditions. A recent series of soil-plant-atmosphere research (SPAR) chamber studies has been conducted for several potato varieties to explore and characterize interactive effects of CO2 and temperature, CO2 and long-term drought, and CO2 and short-term drought on physiological and agronomic responses. This presentation will summarize the unique datasets, and common responses observed across multiple experiments, of the effects of CO2 in combination with either temperature or water stress on: whole plant gas exchange rates, dry matter production, carbon allocation, water use, and plant development.  As future climate change predictions indicate an increased frequency of drought periods in conjunction with elevated CO2 and temperature, such data is critical for improving our assessment tools for developing adaptation strategies.