Impact of Elevated Atmospheric CO2 Concentration on the Growth, and Yield in Two Potato Cultivars

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Concentration of CO2 in the atmosphere is likely to increase up to 550 µmol mol-1 by the middle of 21st century. Such an increase in the atmospheric CO2 would affect plant growth, and as well the productivity of crop plants. A field experiment was conducted with two potato cultivars namely Kufri Surya and Kufri Chipsona-3 grown inside Open Top Chambers (OTCs) at ambient (385±30 µmol mol-1) vs. elevated CO2 (570±50 µmol mol-1) levels during rabi (winter) season of the year 2009-2010. The photosynthetic rate significantly increased in both cultivars when under high CO2 concentration, with the enhancement being more in Kufri Chipsona-3 than in Kufri Surya. There were significantly increased accumulations of reducing, non-reducing and total sugars observed in the leaves of both cultivars as due to CO2 enrichment. Crop Growth Rate (CGR) and Tuber Growth Rate (TGR), in both cultivars, were recorded higher in plants grown under elevated CO2 as compared with the ambient CO2 content. High CO2 increased the partitioning of dry matter towards the tubers at all the harvesting stages. Potato plants grown under elevated CO2 exhibited increased tuber yield due to the enhanced number of tubers per plant. At the final harvest, total tuber fresh weight was by 36% higher, under high CO2 treatments, as compared with that in the ambient. The response of K. Chipsona-3 was more pronounced, to elevated CO2 concentration, as compared with K. Surya. It is concluded that rising atmospheric CO2 in the future climatic change scenario may be beneficial to such tuber crops like potato to enhance growth as well as tuber number and finally yield.