ISHS Acta Horticulturae 440: International Symposium on Plant Production in Closed Ecosystems
APPLICATION OF SYSTEM IDENTIFICATION TO DIAGNOSIS OF RECOVERY OF ROOT FROM TRANSPLANTING INJURY |
| Authors: | T. Torii, T. Okamoto, T. Mukai |
| Keywords: | cross-correlation function, diagnosis, hydroculture, recovery, transplanting injury |
| Abstract:
The need for greenery, especially for hydroculture has been increasing in the office and home. During transplanting from soil culture to hydrocultur, plant roots are injured. From the viewpoint of cost, it is desirable to shorten the curing time for the plants to recover from the transplanting injury. The main goal of this study was to develop a method to diagnose when the roots had sufficiently recovered from the transplanting injury. In this study, two kinds of tests were done under different lighting conditions: step response test and variation test. In these tests, plant responses to light intensity, such as changes in stem diameter and vapor transpiration, were measured. In the step response test, the light intensity was increased from 0 to 120μEm-2s-1 to produce step input. In the variation test, the light intensity was varied by a pseudo random signal (M sequence). Cross-correlation functions of light intensity and plant responses were calculated to understand the similarity of the response to the input quantitatively. The results showed that the response of transpiration approached that before transplanting at three to four weeks after transplanting. The time lag of diameter 1, 2, and 3 approached their original at 4, 7, and 8 week after transplanting. In these results, when the plants had recovered from the root injury, time lags converged to near the pre-transplanting levels. Therefore, it was suggested that we could determine that the plant was recovered from the transplanting injury when the time lag of plant stem diameters from top to the lower part of the plant approached the original pre-transplanting level. | |
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