Factors affecting the rate of photosynthesis

The term rate always involves time, so the rate of photosynthesis can be considered to be how fast photosynthesis takes place. This can be measured by the amount of glucose produced by a plant over a given time. This topic is especially important to scientist and farmers. By understanding the factors that affect the rate of photosynthesis they can do work to try and increase the rate of photosynthesis to increase the yield of a crop.

The three main things affecting the rate of photosynthesis are:

  1. Light
  2. Temperature
  3. Carbon dioxide

These three factors are called LIMITING FACTORS.


In a process like photosynthesis which is affected by more than one factor, its rate is limited by the factor which is closest to its minimum value. So at any point in time if one of the three factors is in low supply, this factor will be the limiting factor. Only a change to the limiting factor will increase or decrease the rate of photosynthesis. Changing the other two will have no effect.


In addition to the three main factors above are other factors such as chlorophyll concentration, water and pollution. Only the three main factors identified above will be considered in further detail.