Which factor is limiting photosynthesis?

Only the factor in shortest supply sets the rate · air is about 0.04% CO₂ · optimum temperature 30 °C in this model · rates in arbitrary units

Conditions around the plant

Light intensity 60%

CO₂ concentration 0.04%

Temperature 25 °C

Rate of photosynthesis

Limiting factor

O₂ bubbles per minute

Rate against light intensity

Teal curve: current conditions · grey curve: before your last CO₂ or temperature change · dashed lines: the CO₂ and temperature limits (the lower one sets the plateau)

Change one condition at a time and watch which factor limits the rate.

On the rising part, light is limiting
More CO₂ raises the plateau
Above the optimum, the rate falls