Question

List the conditions which increase the rate of transpiration.

Answer 1

Transpiration:

1. The evaporation of water from plants is called transpiration.
2. The xylem vessels conduct water from the roots to the aerial parts of the plant from where it is evaporated.
3. Stomata enable transpiration.

Factors that affect the rate of transpiration:

Temperature:

1. A rise in temperature increases the water loss by transpiration.
2. Transpiration increases with an increase in temperature to a certain point. Stomata close when the temperature falls to very low or increases to very high ultimately ceasing the process of transpiration.

Light:

1. The stomatal pore remains open during the daytime to conduct photosynthesis.
2. Open stomata increase transpiration rate in the presence of light.

Humidity:

1. Higher relative humidity of the atmosphere lowers the water potential gradient between the leaf and its surroundings.
2. The lower water potential gradient suppresses transpiration.
3. Lower relative humidity enhances the transpiration rate due to less moisture in the atmosphere.

Wind:

1. Water vapor will not persist near the leaves in a ventilated place.
2. In the absence of wind, the leaves will be surrounded by a vapor that will reduce transpiration.