Photosynthesis is a process by which plants prepare their own food in the presence of water, chlorophyll, sunlight, and CO2. This process occurs mainly in the leaves of the plants. In some other plants, the stems also perform photosynthesis. Photosynthesis occurs in the chloroplast cells of the leaves. There are several factors affecting photosynthesis- its rate and efficiency

Factor Affecting Photosynthesis

Light

It is one of the major factors affecting photosynthesis. Photosynthesis cannot occur in the dark and the source of light for the plants is sunlight. Three attributes of light are important for photosynthesis:

Intensity:Photosynthesis begins at low intensities of light and increases till it is maximum at the brightest time of the day. The amount of light required varies for different plants. Photosynthesis uses maximum up to 1.5 % light in the process and so light is generally not a limitingfactor athigh intensity. However, the light becomes a limiting factor in low intensity because no matter how much water or CO2 is present, without light photosynthesis cannot occur. At high intensities, the temperature of the plant increases which leads to increased transpiration in the plant. This leads to the closing of the stomata which leads to a reduced CO2 intake. Thus, leading to a reduction and finally stoppage of photosynthesis. Therefore, excessive light inhibits photosynthesis.

Quality:Experiments conducted by Engelmann prove that the chlorophyll most effectively absorbs red and blue wavelengths from the entire spectrum of light. Thus, maximum photosynthesis occurs when the plant is exposed to the light of these wavelengths.

Duration:The longer the plant is exposed to light, the longer the process of photosynthesis will continue. As long as the temperature of the plant remains balanced, photosynthesis will occur.