The effect of controlled carbon dioxide environment on in vitro shoot growth and multiplication in Feronia limonia was studied and correlated with photosynthetic performance. The effective quantum yield of in vitro shoot of F. limonia growing on sucrose containing (SCSM) medium under growth room conditions (ambient air control) was sufficient (Y-max = 0.052) for normal growth which was also revealed by 3-fold shoot multiplication rate and higher biomass. Comparatively, low value of Y-max was observed in shoots growing on medium without sucrose (SFSM) under similar conditions leading to decline in growth. When shoots were grown on SCSM under carbon dioxide enriched environment (0.6, 10.0 and 40.0 g m(-3) CO2), significantly higher Y-max and growth was observed as compared to ambient air controls. Maximum yield (0.130) was recorded in shoots growing under 10.0 g m(-3) CO2; however, the best growth was recorded at 0.6 g m(-3) CO2. When the shoots were cultured on sucrose-free medium (SFSM) under carbon dioxide enriched environment, the higher values for effective quantum yield was recorded as compared to ambient air controls. Their Y-max values were comparable with those obtained for shoots growing on SCSM under various concentrations of CO2 (0.6, 10.0 and 40.0 g m(-3)).