ICT International

Advancing soil, plant and environmental decision making

PSY1 Psychrometer (Stem & Leaf) for plant water potential

Continuous plant water potential measurement in megapascals (MPa)

Measuring plant water potential (or plant water stress), the ICT International Psychrometer is a unique, non-destructive, standalone, and in-situ logging device. Applying the research of Dixon and Tyree (1984), the PSY1 Psychrometer is a scientifically validated and widely accepted method for the continuous measurement of plant water potential.

The measurement of water potential in the Soil-Plant-Atmosphere Continuum requires accurate measurements of plant water potential. Traditionally, this has been undertaken using pressure chambers, such as the Scholander Pressure Chamber; however, these require manual measurements to be made at discrete times of the day in a destructive manner. In contrast, the PSY1 Psychrometer continuous (every 10 minutes) measurements of plant water potential in megapascals (MPa). The PSY1 Psychrometer time series data can be combined with other data collected to measure the Soil-Plant-Atmosphere Continuum, such as the SFM1x and SFM1 Sap Flow Meter, or to better understand the water potential gradients that drive ecosystem water flows and govern many plant functions.

The continuous measurement of plant water potential is frequently used to select drought tolerant species in plant breeding.

The Psychrometer logger is available with either a:

  1. Stem chamber (PSY1-Stem)
  2. Leaf Chamber (PSY1-Leaf)

Accessories are available to provide consistent installations:

  • The PSY-IK Psychrometer Installation Kit ensures a correct and successful installation of ICT International Psychrometers.
  • Different stem clamps sizes are available for the PSY1-Stem, to accommodate smaller to larger plant stems or branches
  • A dedicated leaf clamp is available for the PSY1-Leaf.
  • To measure osmotic potential of plant material there is a dedicated Osmotic Potential Insulator (PSY-OPI).