|Eitel, Jan -|
|Keefe, Robert -|
|Davis, Anthony -|
|Vierling, Lee -|
Submitted to: Sensors
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 25, 2010
Publication Date: March 29, 2010
Citation: Eitel, J.U., Keefe, R., Long, D.S., Davis, A., Vierling, L. 2010. Active Ground Optical Remote Sensing for Improved Monitoring of Seedling Stress in Nurseries. Sensors. 10(4):2843-2850. Available: http://www.mdpi.com/journal/sensors. Interpretive Summary: Advances in agricultural technology have led to the development of active sensors that can detect the amount of light reflected from plants as an indicator of plant health. This study investigated the potential usefulness of the Holland Scientific ACS 470 active sensor that is specially designed to provide its own illumination and measure reflectance in the red, red-edge, and near infrared portions of the electromagetic spectrum. Using the red and red-edge information, the sensor gave improved performance over conventional sensing in detecting stress in Scotts pine seedlings. This study shows that the ACS 470 sensor has the potential to detect stress in a nursery setting. Improvements could be made to adapt the sensor to sensing stress from a moving overhead irrigation boom in a nursery.
Technical Abstract: Active ground optical remote sensing (AGORS) devices mounted on overhead irrigation booms could help to improve seedling quality by autonomously monitoring seedling stress. In contrast to traditionally used passive optical sensors, AGORS devices operate independently of ambient light conditions and do not require spectral reference readings. Besides measuring red (590-670 nm) and near-infrared (>760 nm) reflectance AGORS devices have recently become available that also measure red-edge (730 nm) reflectance. We tested the hypothesis that the additional availability of red-edge reflectance information would improve AGORS of plant stress induced chlorophyll breakdown in Scots pine (Pinus sylvestris). Our results showed that the availability of red-edge reflectance information improved AGORS estimates of stress induced variation in chlorophyll concentration (r2 > 0.73, RMSE < 1.69) when compared to those without (r2 = 0.57, RMSE = 2.11).