In order to detect apple tree growth status fast and accurately, four sensitive wavebands (364nm, 652nm, 766nm, 810nm)
were obtained by analyzing the correlation between the apple leaves spectra and their nitrogen contents plus adopting the
segment reduced precise sampling methods. A rapid determination model of apple leaf nitrogen content suitable for
portable detector was built. Then a portable spectroscopy-based device was developed. It consists of an optical unit and a
control unit. The optical channel was consisted of convex lens, optical filter, photoelectric detector and airtight
mechanical exine. The optical unit was used to capture, transit, transform and submit the optical signal. The controller
was consisted of operation, input, display, data storage and power control unit adopting JN5139 as main control unit.
Controller was the coordinator in building the wireless network. And it was also responsible for receiving the measured
data from sensor, calculating vegetation index, and displaying and storing the calculated results. The experiments
showed that the correlation coefficient between the measured nitrogen content and the predicted nitrogen content reached
to 0.857. It illustrated that the apple tree nitrogen detector was practical and could be used to detect leaf nitrogen content
in apple orchard.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yao Zhang ; Lihua Zheng ; Minzan Li ; Xiaolei Deng and Xiaofei An
"Development of a portable spectroscopy-based device to detect nutrient status of apple tree", Proc. SPIE 8527, Multispectral, Hyperspectral, and Ultraspectral Remote Sensing Technology, Techniques and Applications IV, 852716 (November 9, 2012); doi:10.1117/12.977403; http://dx.doi.org/10.1117/12.977403