Net photosynthetic rate (Ps) increased under ECO2+ AO3 by
57.93 and 65.36% and under ECO2+ EO3by 47.17% and 21.13% at 30
and 60 DAE, respectively compared to ACO2+ AO3, while significantly decreased under ACO2+ EO3and ACO2+ AO3treatments at
both the ages compared to ACO2+ RO3(Fig. 1). Stomatal conductance (Cs) decreased under ACO2+ EO3and ACO2+ AO3at both the
ages compared to ACO2+ RO3(Fig.1). Reductions in Cswere 37.7% in
ECO2+ EO3and 27.9% in ECO2+ AO3compared to ACO2+ AO3at 60
DAE. Transpiration rate (E) and internal CO2 concentration
increased under ECO2+ AO3and ECO2+ EO3compared to ACO2+
AO3and decreased under ACO2+ EO3and AO3+ ACO2compared to
ACO2+ RO3 at both the ages (Fig. 1). WUE decreased under O3
treatments both at ambient and elevated levels compared to
ACO2+ RO3, whereas increased significantly in ECO2+ AO3 and
ECO2+ EO3compared to ACO2+ AO3(Fig. 1). Three way ANOVA test
showed that changes in Ps
, Cs
, E and WUE were highly significant
due to all the individual factors and their interactions, except
age CO2 interaction for Ps
. Changes in E rate were also not
significant due to age CO2and age CO2 O3(Table 1)