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

Concentration of CO 2 in the atmosphere is likely to increase up to 550 µmol mol -1 by the middle of 21 st century. Such an increase in the atmospheric CO 2 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 CO 2 (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 CO 2 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 CO 2 enrichment. Crop Growth Rate (CGR) and Tuber Growth Rate (TGR), in both cultivars, were recorded higher in plants grown under elevated CO 2 as compared with the ambient CO 2 content. High CO 2 increased the partitioning of dry matter towards the tubers at all the harvesting stages. Potato plants grown under elevated CO 2 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 CO 2 treatments, as compared with that in the ambient. The response of K. Chipsona-3 was more pronounced, to elevated CO 2 concentration, as compared with K. Surya. It is concluded that rising atmospheric CO 2 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.