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
Amount in controversy Amount in controversy Amount in controversy (sometimes called jurisdictional amount) is a term used in civil procedure to denote the amount at stake in a lawsuit, in particular in connection with a requirement that persons seeking to bring a lawsuit in a particular court must be suing for a certain minimum amount (or below a certain maximum amount) before that court may hear the case. In United States federal courts, the term currently applies only to cases brought under diversity jurisdiction, meaning that the court is able to hear the case only because it is between citizens of different states.