Growth, yield and quality attributes of a tropical potato variety (Solanum tuberosum L. cv Kufri chandramukhi) under ambient and elevated carbon dioxide and ozone and their interactions

The present study was designed to study the growth and yield responses of a tropical potato variety (Solanum tuberosum L cv. Kufri chandramukhi) to different levels of carbon dioxide (382 and 570 ppm) and ozone (50 and 70 ppb) in combinations using open top chambers (OTCs). Plants were exposed to three ozone levels in combination with ambient CO2 and two ozone levels at elevated CO2. Significant increments in leaf area and total biomass were observed under elevated CO2 in combination with ambient O-3 (ECO2+AO(3)) and elevated O-3 (ECO2+EO3), compared to the plants grown under ambient concentrations (ACO(2)+AO(3)). Yield measured as fresh weight of potato also increased significantly under ECO2+AO(3) and ECO2+EO3. Yield, however, reduced under ambient (ACO(2)+AO(3)) and elevated ozone (ACO(2)+EO3) compared to ACO(2) (filtered chamber). Number, fresh and dry weights of tubers of size 35-50 mm and > 50 mm used for direct consumption and industrial purposes, respectively increased maximally under ECO2+AO(3). Ambient as well as elevated levels of O-3 negatively affected the growth parameters and yield mainly due to reductions in number and weight of tubers of sizes >35 mm. The quality of potato tubers was also modified under different treatments. Starch content increased and K, Zn and Fe concentrations decreased under ECO2+AO(3) and ECO2+EO3 compared to ACO(2)+AO(3). Starch content reduced under ACO(2)+AO(3) and ACO(2)+EO3 treatments compared to ACO(2). These results clearly suggest that elevated CO2 has provided complete protection to ambient O-3 as the potato yield was higher under ECO2+AO(3) compared to ACO(2). However, ambient CO2 is not enough to protect the plants under ambient O-3 levels. Elevated CO2 also provided protection against elevated O-3 by improving the yield. Quality of tubers is modified by both CO2 and O-3, which have serious implications on human health at present and in future. (C) 2013 Elsevier Inc. All rights reserved.