1. Light: If the intensity of light increases, the rate of transpiration increases. Blue light accelerates the sensation.
2. Temperature: Normal respiration occurs at a temperature of 10-250C. Evaporation rate increases as temperature increases. As a result, the transpiration increases.
3. Airflow: Airflow removes water vapor quickly. It increases the transpiration rate.
4. Atmospheric pressure: As the atmospheric pressure increases, the rate of respiration increases. Therefore, the transpiration rate is higher in high mountains.
5. Concentration of CO2 : The rate of transpiration increases as the concentration of CO2 increases. However, when the concentration of CO2 increases more, the stomata close.
6. Relative humidity: As the relative humidity of the atmosphere increases, the rate of transpiration decreases.
7. Soil water content: If the soil water content is high, the rate of transpiration increases.