A. Aien - Agricultural Research Center of Jiroft and Kahnooj, Jiroft, Iran
M. Pal - Indian Agricultural Research Institute (IARI)
S. Khetarpal - Indian Agricultural Research Institute (IARI)
S. Kumar Pandey - Indian Agricultural Research Institute (IARI)

Concentration of CO۲ in the atmosphere is likely to increase up to ۵۵۰ µmol mol-۱ by the middle of ۲۱st century. Such an increase in the atmospheric CO۲ 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-۳ grown inside Open Top Chambers (OTCs) at ambient (۳۸۵±۳۰ µmol mol-۱) vs. elevated CO۲ (۵۷۰±۵۰ µmol mol-۱) levels during rabi (winter) season of the year ۲۰۰۹-۲۰۱۰. The photosynthetic rate significantly increased in both cultivars when under high CO۲ concentration, with the enhancement being more in Kufri Chipsona-۳ 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 CO۲ enrichment. Crop Growth Rate (CGR) and Tuber Growth Rate (TGR), in both cultivars, were recorded higher in plants grown under elevated CO۲ as compared with the ambient CO۲ content. High CO۲ increased the partitioning of dry matter towards the tubers at all the harvesting stages. Potato plants grown under elevated CO۲ exhibited increased tuber yield due to the enhanced number of tubers per plant. At the final harvest, total tuber fresh weight was by ۳۶% higher, under high CO۲ treatments, as compared with that in the ambient. The response of K. Chipsona-۳ was more pronounced, to elevated CO۲ concentration, as compared with K. Surya. It is concluded that rising atmospheric CO۲ 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.

Dry matter partitioning, Elevated CO۲, Photosynthesis, Potato, Sugars, Yield