1. Remote Sensing to Estimate Chlorophyll Concentration Using Multi-Spectral Plant Reflectance P. R. Weckler Asst. Professor M. L. Stone Regents Professor N. Maness Professor R. Jayasekara Research Engineer C. Jones Research Engineer

2. Objective Estimate Chlorophyll concentration using chlorophyll content and biomass

3. Sensors Passive Sensor - OSU Plant Reflectance sensor Active Sensor - Patchen Weedseeker™ PHD 600 Sensor - Ntech Greenseeker™ Sensor Multi-Spectral Camera

4. Sensing Equipment Spring, 1999 and 2000Fall, 2000 and Spring, 2001 Fall, 2002 OSU Reflectance Sensor Patchen Weedseeker™ PHD 600 Sensor OSU Reflectance Sensor Ntech Greenseeker™ Sensor No camera usedOlympus D-360L digital camera DuncanTech MS3100 multispectral camera

5. Sensors

6. Experimental Plots Vegetation Through Multi-spectral Camera Spinach Plot with Reflectance Targets

7. Results

9. StudyNDVI vs Biomss NDVI vs. Chlorophyll Yield % Vegatative Coverage vs. Biomass NDVI/%VC vs. Chlorophyll Concentration Spring,19990.80 No camera data ----------- Spring, 20000.810.77No camera data ----------- Fall, 20000.930.73 0.02 Spring, 20010.930.870.980.38 Fall, 20020.940.920.850.03

10. Conclusions The NDVI readings gathered by the handheld sensors and the multispectral camera were sensitive to changes in plant biomass and plant chlorophyll content in spinach. This study reaffirmed the correlation between %VC and dry biomass found by Lukina et al. (1999, 2000) and Ter-Mikaelian and Parker (2000). High correlation was observed between the %VC of the spinach as measured with digital imagery and the spinach biomass as measured in the laboratory (r 2 = 0.73 to 0.98).

11. Conclusions The findings of Lukina et al. (1999, 2000) and Sembiring (1998) were also supported regarding NDVI readings producing a stronger estimate of chlorophyll content then of chlorophyll concentration. NDVI derived from processing images from a multispectral camera correlated well with handheld sensor NDVI. The multispectral camera provided accurate %VC information that correlated well with biomass results.

12. Further Studies Low correlations when predicting chlorophyll concentration from estimates of biomass and NDVI may suggest further investigation in following areas: - canopy stacking - background interference with sensors

13. QUESTIONS? Acknowledgments Dr. Jerry Brusewitz Ted Kersten D. Chrz Bruce Bostian Oklahoma Vegetable Research Station,Bixby,Oklahoma