Studies On The On-line Non-invasive Automatic Monitoring Technique Of Plant Water Potential

As a parameter describing the direction and amount of water movement in the body of plants,water potential is a fundamental physiological parameter of plants which plays important role in many fields of scientific research. So measuring techniques of plant water potential as means of scientific research is intensively interested. While at present various measuring techniques of plant water potential have been developed and used mainly for the study of plant physiology,these existing measuring techniques are not well fit for other application fields such as water-saving agriculture and monitoring and control of structured agriculture environments. In order to meet the requirements of methodology in the study of plant water potential and promote the development of related measuring techniques,the paper is dedicated to the research of on-line non-invasive automatic monitoring technique of plant water potential.The paper expounds on the following aspects.Firstly,on the basis of analysis of current techniques for measuring plant water potential and with the dynamic characteristics of vapor diffusion in consideration,the relationship between the transient process of humidity at the position of the sensor and the water potential of the plant sample is studied in depth,and the corresponding testing apparatus for the on-line non-invasive automatic monitoring of plant water potential is designed.Secondly,with the demands of monitoring plant water potential in mind,the apparatus has been tested with satisfactory resultsThirdly,utilizing that testing apparatus and NaCl solutions at 20 C,a study is preformed to investigate the on-line non-invasive automatic monitoring technique of plant water potential,with some models of monitoring plant water potential properly established. Results show that the second model of monitoring plant water potential is desirable after comparing. Then,comparative measurements are done with KC1 solutions,using both the testing apparatus and the commercial Wescor waterpotential meter. Positive results are obtained on the feasibility of the model used for on-line non-invasive automatic monitoring of plant water potential.Finally,the design of a practical system for the on-line non-invasive automatic monitoring of plant water potential is presented on the basis of the above research work.At the end of the paper,the results of the research are summarized for further improvement.