Factors Affecting Rate of Transpiration:

Temperature:

• As temperature increases, the kinetic energy of water molecules within the plant also increases.
• This heightened kinetic energy accelerates the process of evaporation and diffusion from the mesophyll cells into the surrounding air spaces.
• Consequently, the rate of transpiration increases with higher temperatures, as more water molecules evaporate from the leaf surfaces.

Humidity:

• Humidity refers to the amount of moisture present in the air.
• Low humidity levels create a more significant difference in water vapor concentration between the leaf and the surrounding atmosphere.
• This steep concentration gradient facilitates the rapid movement of water vapor from the leaf into the drier air, increasing the rate of transpiration.
• Conversely, high humidity reduces the transpiration rate since the concentration gradient is less pronounced.

Wind Speed:

• Wind speed plays a crucial role in transpiration by affecting the boundary layer of still air surrounding the leaf.
• When there is a breeze or wind, it removes the water vapor molecules accumulating near the leaf surface, maintaining a steeper concentration gradient.
• This removal of water vapor molecules ensures that the air surrounding the leaf remains drier, allowing for a faster diffusion of water vapor from the leaf surface.
• Consequently, higher wind speeds lead to an increase in the rate of transpiration.