Assessment of plants' reaction to drought stress using THz time domain spectroscopy

The feasibility of THz time-domain spectroscopy for monitoring the leaf water content of plants has been shown in earlier publications. Here, we present extensive measurement series on different plant species. Our measurements show that the behavior of a plant under drought stress is a complex process that is controlled by physiological processes inside the plant. Thus, the loss of water from a leaf that is attached to a plant under drought stress cannot be compared to other materials like wet cloth or paper that will just physically dry when exposed to the air. As the physiological regulation differs in different plant species, these differences become apparent in our measurements.