The Effects of Elevated Concentrations of Carbon Dioxide and Ozone on Potatoe (Solanum tuberosum L.) Yield

Abstract

Potatoes (Solanum tuberosum L. cv. Bintje) were grown in open top chambers at Teagasc, Crops Research Centre, Oak Park, Carlow and exposed to ambient and elevated concentrations of CO2 in combination with ambient and elevated concentrations of O3 in the 1998 and 1999 growing seasons. Exposure to elevated concentrations of O3 caused visual damage to the leaves of the potato plants in both years of the study. In 1999, ozone damage to leaves was significantly reduced in the presence of elevated concentrations of CO2. Stomatal conductance was reduced by elevated CO2 and was reduced further by the elevated O3 treatment under elevated CO2. Exposure to elevated CO2 increased tuber fresh weight yield by 32% in both years of the study. The yield increase was attributable to larger tuber sizes and not to an increase in the number of tubers. Tuber yield was unaffected by elevated O3 at ambient concentrations of CO2 in both years of the study. In 1999, the yield increase induced by elevated CO2 was substantially reduced by the presence of elevated O3.