An Optical Detector for Determining Chlorophyll and Nitrogen Concentration Based on Photoreaction in Apple Tree Leaves

摘要

It is a practical need for orchard production to detect chlorophyll and nitrogen concentration in apple tree leaves quickly. The interaction between apple tree leaves and sun light was analyzed through investigating the characteristics of spectral signatures of leaves, and a portable chlorophyll and nitrogen concentration detector was developed for apple tree leaves. Firstly 60 apple tree leaf samples were collected. The chlorophyll, nitrogen concentrations and reflectance were acquired in laboratories, then the spectral features of samples were analyzed, and light reaction characteristics were revealed accordingly. Therefore, the characteristic wavebands were obtained to predict the chlorophyll and nitrogen content in apple tree leaves effectively, and then the determination models for forecasting chlorophyll and nitrogen concentrations in apple leaves were established and validated. Finally a portable chlorophyll and nitrogen contents detector for apple leaves was developed based on the determination models. The performance test results showed that the detector could be used to detect the chlorophyll and nitrogen concentrations in apple leaves with high accuracy.