Environmental Factors that Increase Transpiration Rate
- High temperature: increases capacity of atmospheric air to hold more water vapour; increases internal temperature of leaf, which in turn increases LHV and therefore enhances evaporation from the leaf cells.
- Low relative humidity: saturation deficit is high; more water vapour diffuses out of the leaf into the atmosphere
- Wind: carries away water vapour around leaves, maintaining a high diffusion gradient between the inside and outside of the leaf
- High light intensity: causes stomata to open fully, exposing sub-stomatal air into direct contact with the outside environment.
- Low atmospheric pressure/high intercellular air pressure: more water vapour is lost to the atmosphere due to the pressure deficit in the atmosphere
- Adequate water supply from the soil: walls of mesophyll cells are kept continuously wet