The Importance of Measuring Vapor Pressure Deficit

VPD chart- cannabis

What is Vapor Pressure Deficit? Vapor Pressure Deficit (VPD) is a pressure value that combines both temperature and relative humidity(RH). VPD allows growers to understand stress in their plants. It is a measure of the evaporation potential, or the difference in “wetness” (the amount of water vapor), of the air at the leaf versus the […]