Effect of increasing relative humidity on vapor pressure gradient from leaf to air at a constant temperature of 30°C.
| Leaf and air temperature (°C) | 30 | 30 | 30 |
| Relative humidity of air (%) | 20 | 50 | 80 |
| Vapor pressure at evaporating leaf surface (kPa) | 4.24 | 4.24 | 4.24 |
| Vapor pressure in air at indicated temp.(kPa) | 0.85 | 2.12 | 3.39 |
| Vapor pressure gradient from leaf to air (kPa) | 3.39 | 2.12 | 0.85 |