Plant Health and Measuring the Red Edge

Measuring plant health in the field can be done with a field portable spectroradiometer from Spectral Evolution. The PSR+ is a full range 350-2500nm NIR spectrometer that is ideally suited for taking vegetation measurements using our unique leaf clip and ILM-105 illumination source.

Many factors can affect plant health:

  • Lack of water
  • Over watering
  • Under fertilization
  • Pest infestation
  • Poor drainage
  • Soil compaction
  • Lack of nutrients

Using a PSR+ agricultural spectroradiometer and leaf clip, you can scan individual plant leaves and measure health and stress by looking at the red edge in the 680-760nm range of the leaf spectra. The red edge is usually centered around 720nm. In healthy plants the red edge shifts to the longer wavelengths – to the right on the spectra. There is also a deeper absorption feature at 680nm indicating there is more photosynthesis going on (more light being absorbed). In a stressed plant, the red edge is further to the left – toward the shorter wavelengths and there is less absorption and more reflectance in a feature at 630nm.

The PSR+ combines high resolution with high sensitivity as well as rugged construction for field use. All solid state arrays mean no moving optical parts for greater reliability. Lightweight and with 2 slide-in lithium-ion batteries for a full day in the field, the PSR plus is designed for single-user operation. The leaf clip has an external trigger for ease-of-use and an external illumination source to keep heat away from your samples.

Our leaf clip is ergonomically designed for a single user. It features an external trigger, built-in reference panel, and external illumination source to keep heat from affecting your sample measurements.