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System and method for measuring water content in a leaf

Agricultureirrigation water managementleaf water contentplant wellnessterahertz enhanced visionterahertz laser


The invention aims to respond to the growing demand for quick and non-invasive tools for measuring the «plant wellness» (i.e. the best physiological condition in which the single plant can grow up), by proposing an in-field method for determining the water content of the plant (leaves) and the related apparatus and management tool. The technology employs a Terahertz enhanced vision system based on THz spectroscopy.

Technical features

The proposed method and apparatus is based on an electromagnetic sensor capable of getting the right information from the inside of the leaf without any contact and translating the internal amount of water into a useful index, i.e. measuring the fundamental parameter to determine if the plant is under suffering. The system is composed of a terahertz (THz) light source, a THz detector, a vision system and a computer for real-time data analysis. Once chosen the leaf to be examined, the Thz light passes through the leaf and reaches the detector, which transforms the light into an electronic signal; then the electronic signal is sent to the computer. At the same time, the vision system measures the coordinates of the leaf relative to the THz light, together with the leaf projective area. The whole acquisition is sent to the computer, which finally derives the amount of water contained inside the leaf.
A first lab-made prototype has been validated in field showing promising results.

Possible Applications

  • Agriculture (irrigation, crop monitoring, harvesting time, …);
  • Water management on farming soils;
  • High-value cultivars cultivation;
  • Plant nurseries.


  • Simple, fast and reliable tool;
  • Non-invasive and robust method;
  • In field or in lab measurement system;
  • Measures repeatability and accuracy (> 95% in laboratory environment);
  • Increase of crops yield (in terms of quality and also quantity).