|Kim, M - USDA/ARS|
|McMurtrey Iii, James|
|Mulchi, C - UNIVERSITY OF MARYLAND|
|Deitzer, Gerald - UNIVERSITY OF MARYLAND|
|Chappelle, E - NASA|
Submitted to: Applied Optics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 1, 2000
Publication Date: January 5, 2000
Interpretive Summary: An evaluation of fluorescence imaging system technology was conducted. Fluorescence imaging systems have been developed for monitoring crop stress conditions in plants leaves. Current methods for accurately quantifying crop stress across the leaf surface are difficult, tedious, and time consuming. There is a need for rapid and precise fluorescence techniques to quantify the variability across crop leaves under going plant stress conditions. Development of portable bench level fluorescence sensing instrumentation, methods, and techniques will greatly enhance the ability of quick assessment of plant stress conditions while remedial corrective actions can still be implemented. The study determined favorable advantages to fluorescence imaging technologies when assessing live plant condition and physiological status in leaves.
Technical Abstract: The performance of a four band fluorescence imaging system (FIS) for steady-state fluorescence properties of live plant leaves was assessed. The imaging system consisted of a UV excitation source, sample holder, four interference filters, a CCD digital camera, a 12 bit resolution A/D converter, and a computer interface for instrument control and data collection. Evaluation of the linear responsiveness of the CCD as a function of integration time and intensity on a flat field target demonstrated a near linear relationship (r2=.99). FIS image of plant leaves showed the utility of assessing leaf morphology and plant stress damage across leaves. The FIS instrumentation was able to measure fluorescence from the entire leaf surface which allows an assessment of the distribution of the spacial variability across the leaf surface. This enables a more accurate assessment of the total leaf surface than previous methods which used individual integrated-point measurements across the leaf.