Using transpiration chambers to detect initial transpiration in cuttings and quantify transpiration in seedlings

A controlled environment chamber was developed to quantify transpiration in dogwood seedlings (Cornus florida and Cornus kousa) and poinsettia (Euphorbia pulcherrima) cuttings. The chamber included both incandescent and fluorescent lights mounted on an adjustable shelf to accommodate a range of plant heights and replicated transpiration stations consisting of one infrared temperature sensor and scale per station. This system was used to detect transpiration on seedlings gravimetrically and by an increase in leaf temperature. For cuttings, the chamber consisted of solely an incandescent light source and three scales. Both systems used an air conditioning system which also permitted control of the vapor pressure deficitair. In both the seedlings and cuttings, the chamber system was able to maintain a constant VPDair and detect and record transpiration.