Effects of elevated CO2 concentration on seedling growth rate and photosynthesis in Hevea brasiliensis.

To study the effect of elevated CO2 concentration on plant growth and photosynthesis, two clones of Hevea brasiliensis were grown in polybags and exposed to elevated concentration (700 :::l:: 25 ppm) for 60 days. There was higher biomass accumulation, leaf area and better growth when compared to ambient air grown plants. From A/Ci curves it is clear that photosynthetic rates increases with increase in CO2 concentrations. After 60 days of exposure to higher CO2 concentration, a decrease in the carbon assimilation rate was noticed.