Which of the following exhibits a direct proportionality to transpiration?
Which of the following exhibits a direct proportionality to transpiration?
The correct option is C Temperature and wind
Light, especially light intensity, has an effect on opening and closing of stomatal pores and thus on the rate of transpiration. The rate of transpiration is highest during the daytime. But light intensity is not directly proportional to transpiration.
Relative Humidity (RH) is inversely proportional to the rate of transpiration. If RH increases, the air becomes moister and stomata get closed and limit the exit of water vapour from the pores. As the RH starts decreasing, the air becomes drier and rate of transpiration increases.
The rate of transpiration is fastest when the air temperature is between 20°C to 30°C. At these temperatures, the stomatal apertures or opening are generally widest. In general, the stomata close at temperatures about 0°C and progressively increase in aperture up to about 30°C.
Wind affects transpiration by removing that thin moist layer of air, called boundary layer, which lies next to the surface of a leaf. This moist air causes a lesser water potential gradient from the leaf resulting in a reduced rate of transpiration. This layer also reduces light penetration into the leaf. But with the wind, this boundary layer is replaced with drier air thus increasing water potential gradient and enhancing transpiration
Temperature and wind
Light, especially light intensity, has an effect on opening and closing of stomatal pores and thus on the rate of transpiration. The rate of transpiration is highest during the daytime. But light intensity is not directly proportional to transpiration.
Relative Humidity (RH) is inversely proportional to the rate of transpiration. If RH increases, the air becomes moister and stomata get closed and limit the exit of water vapour from the pores. As the RH starts decreasing, the air becomes drier and rate of transpiration increases.
The rate of transpiration is fastest when the air temperature is between 20°C to 30°C. At these temperatures, the stomatal apertures or opening are generally widest. In general, the stomata close at temperatures about 0°C and progressively increase in aperture up to about 30°C.
Wind affects transpiration by removing that thin moist layer of air, called boundary layer, which lies next to the surface of a leaf. This moist air causes a lesser water potential gradient from the leaf resulting in a reduced rate of transpiration. This layer also reduces light penetration into the leaf. But with the wind, this boundary layer is replaced with drier air thus increasing water potential gradient and enhancing transpiration
