Elevated CO2: Overpowering the Growth-Retarding Effects of Ozone in Palak
Kumari, S., Agrawal, M. and Tiwari, S. 2013. Impact of elevated CO2 and elevated O3 on Beta vulgaris L.: Pigments, metabolites, antioxidants, growth and yield. Environmental Pollution 174: 279-288.
As expected, the results of the analysis revealed that elevated CO2 enhanced various plant growth parameters in palak, including root length, shoot length, number of leaves, leaf area, root biomass, shoot biomass, total plant biomass, and yield (compare the ECO2 values in Table 1 with the ACO2 values), while elevated concentrations of ozone had a negative effect (compare the EO3 values in Table 1 with the ACO2 + AO3 values). When enhanced ozone and enhanced carbon dioxide were tested together, however, the growth-enhancing effects of CO2 were sufficient in every instance to overpower the growth-retarding effects of ozone for every plant parameter measured (compare the ECO2 + EO3 values in Table 1 with the ACO2 + AO3 values).
Table 1. Growth parameters of palak plants under different treatments of O3 and CO2, individually and in combination at 50 days after germination (DAG). Adapted from Kumari et al. (2013).
In discussing the various findings of their work, Kumari et al. concluded that for the IPCC-predicted atmospheric concentrations of CO2 and O3 at the end of the century, "palak is going to be benefited as biomass enhancement was more under ECO2 + EO3 compared to ACO2 + AO3." And that's great news for lovers of this popular leafy vegetable in India and elsewhere across the globe.
IPCC. 2007. Climate Change 2007. The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, United Kingdom..