Elevated carbon dioxide (CO2) improves plant growth and can mitigate the negative impact of drought stress on plants. United Arab Emirates (UAE) is
under imminent drought stress and has a growing agricultural sector with huge amount of fresh water requirement for irrigation. A study was designed to quantity the benefits of the elevated CO2 in the context of the current drought stress in UAE. The aim is to investigate the drought stress mitigating effects of elevated CO2 under water stress. The combined effects of CO2 and water stress on Tabernaemontana divaricata growth was investigated using three levels each of CO2 and water stress.
Results/Conclusions
HWS (30% field capacity) and MWS (70% field capacity) water-stressed plants under enriched CO2 levels (i.e. 1000 umol/mol and 700 umol/mol) had higher leaf water potential (LWP), but lower total chlorophyll content (TCC). In addition, enriched CO2 conditions, especially 1000 umol/mol, decreased the impact of drought stress on percent maximum quantum yield of PSII (Fv/Fm) compared to ambient CO2. In comparison with ambient CO2 , the 1000 mol/mol CO2 imparted higher drought stress tolerance to plants in combination with MWS treatment by reducing the irrigation water requirement up to 30% without compromising plant performance in T. divaricata.