Yield and water use of potato under elevated carbon dioxide

The increasing CO2 content in the atmosphere, due to the combustion of fossil fuels is determining a change in climate and is expected to affect the yield of crop.The present research was aimed to quantify the effect of a CO2 concentration of 560 ppm maintained in the open filed with a Free Air Carbon dioxide Enrichement (FACE) apparatus, on the tuber yield and water use of a Bintje potato crop.Vegetative habit of the plants was little affected. FACE plants were slightly smaller due to a greater partitioning of carbohydrate to underground sinks. The yield was increased by the FACE treatment of about 35% .Soil hydrological balance failed to demonstrate differences in water use by the crop, while energy balance approach worked better. Seasonal water use was over 25% higher in control plots. These two data factored to yield a water use efficiency 60% higher in FACE plots.