2005 Volume 43 Issue 1 Pages 47-55
The physiological adaptation response to environmental stress of a plant can induce changes in physiological and physical conditions of the plant. These changes influence the dielectric properties of the plant, which can be detected by measuring complex dielectric properties of plant materials. The dielectric properties of tomato leaves during salt stress at NaCl concentrations of 0, 50, 100 and 200 mmo1L-1in nutrient solution were measured with an open-ended coaxial probe from 0.3 to 3 GHz, as well as changes in water content, photosynthetic rate, stomatal conductance and water potential which reflect the physiological condition of the plant. Experimental results showed the potential of microwave sensing as a method for monitoring adaptation responses in tomato plants under salt stress. In order to clarify the principle of detecting adaptation responses to salt stress by microwave method, chemical analyses were conducted. The chemical analyses results suggest an increase in the effects of osmoregulation by the tomato plant. The dynamic adaptation responses of the tomato plant to salt stress can be detected non-invasively by microwave sensing which detects the changes in complex dielectric properties of the plant.
