Vapour-pressure deficit the plant may dry out and die. For this reason the ideal range for VPD in a greenhouse is from 0.45 kPa to 1.25 kPa, ideally sitting at around 0.85 kPa. As a general rule, most plants grow well at VPDs of between 0.8 and 0.95 kPa. In ecology, it is the difference between the actual water vapour pressure and the saturation water vapour pressure at a particular temperature. Unlike relative humidity, vapour-pressure deficit has a simple nearly straight-line relationship to the rate of evapotranspiration and other measures of evaporation. To compute the VPD, we need the ambient (greenhouse) air
Raincoat Raincoat A raincoat or slicker is a waterproof or water-resistant coat worn to protect the body from rain. The term rain jacket is sometimes used to refer to raincoats that are waist length. A rain jacket may be combined with a pair of rain pants to make a rain suit. Modern raincoats are often constructed of breathable, waterproof fabrics such as Gore-Tex or Tyvek and coated nylons. These fabrics allow some air to pass through, allowing the garment to 'breathe' so that sweat vapour can escape. The amount of pouring rain a raincoat can handle is sometimes measured in the