Question

In case of water deficiency why does the rate of photosynthesis reduce

Answer 1

Actually the water needed for photosynthesis is only one percent of total water absorbed, rest is used in transpiration and maintenance of the shape of leaves.
If the water available is less, then it will lead to wilting of leaves, closing of stomata and other effects which lead to lower surface of the leaf available for the process and hence lower photosynthesis.

Hope you will understand.

Answer 2

Answer:

Water is required for photosynthesis. Look at the letters in the image below, Sugars require Carbon, Hydrogen, and Oxygen. The plants get the carbon and oxygen from carbon dioxide, but need water for the hydrogen.

Explanation: