Vapor pressure deficit[ˈveɪpə ˈprɛʃə ˈdɛfɪsɪt]
The amount of water in the form of vapor present in the air is measured by the vapor pressure deficit or VPD. In the cannabis industry, VPD is utilized, especially by indoor growers, to affect their yields. This is because VPD influences the plant’s transpiration process, which directly impacts its health and well-being.
To calculate the VPD, growers consider the temperature, relative humidity, and saturated vapor pressure of their growing space.