Question

Write a note on the weighing method to check transpiration.

Answer 1

Weighing method is used for measurement of transpiration.
Transpiration is the loss of water by plants.

Complete answer: Weighing method is a method to check transpiration in which a small lightweight potted plant can be weighed before and after the end of a certain period of time. The soil surface and the pot should be fully covered to prevent evaporation from the surfaces other than the plant. The loss in weight by the plant during that time is due to the loss of water by transpiration.

Additional information: The rate of transpiration can be calculated by measuring the distance traveled by an air bubble in a capillary tube over a given time.
The faster the bubble moves, the greater the rate of water uptake and so the greater the assumed rate of transpiration. The rate of transpiration is affected by several factors, including temperature, humidity, wind speed & light intensity.

There are 3 different types of transpiration.
They are - Stomatal Transpiration, Lenticular Transpiration & Cuticular Transpiration.
Increased light intensity will increase the rate of photosynthesis, so more water is drawn into the leaves where photosynthesis primarily takes place, and therefore the rate of transpiration is greater.

Note: A potometer is a device that measures the rate at which a plant draws up water. Since the plant draws up water as it loses it by transpiration, we are able to measure the rate of transpiration.