What was done
The authors grew potato (Solanum tuberosum L. cv. Katathdin) in controlled environment chambers maintained at atmospheric CO2 concentrations of 350 and 700 ppm for two or four weeks (during tuber initiation and tuber bulking, respectively) under normal and low light conditions to study the effects of elevated CO2 and light on tuber growth during these two phenological stages.

What was learned
Under normal light conditions, elevated CO2 increased potato tuber cell numbers by 67 and 18% at tuber initiation and bulking growth stages, respectively.  These CO2-induced increases in cell numbers ultimately increased tuber biomass in normal light conditions by 36%, regardless of growth stage.  In contrast, elevated CO2 did not significantly affect tuber cell numbers at low light conditions at either tuber growth stage.

What it means
As the atmospheric CO2 concentration increases, potato plants will likely increase their photosynthetic rates, which should stimulate cell proliferation as observed in this study.  In turn, greater cell numbers should lead to enhanced tuber biomass production under normal light environments.  Thus, potato production will likely increase in the future as the air's CO2 content continues to rise.