
In last 250 years, CO2 levels have increased from 280 to 390 ppm (IPCC 2007). Elevated CO2 reduces N content and alters the concentrations of secondary metabolites in plants (Sun et al. 2013). Therefore, the present studies were undertaken on the effects of increased levels of CO2 on enzymatic activity and secondary metabolites in chickpea. Helicoverpa armigera damages chickpea plants at all the stages.