Blackman proposed the law of limiting factor. According to this law,
When a chemical process is affected by more than one factor, its rate will be determined by the factor which is nearest to its minimal value: It is the factor which directly affects the process if its quantity is changed.
- The rate of photosynthesis is affected mainly by the concentration of CO2 light intensity and temperature.
- As the light intensity is increased, the rate of photosynthesis increases proportionately until some other factor like CO2 or temperature may become limiting.
- Similarly, if the concentration of CO2 is increased the rate of photosynthesis increases until light may become a limiting factor.