The spectral signatures of crop canopies in the field provide much information relating morphological or quality characteristics of crops to their optical properties. This experiment was conducted using two winter-wheat ( Triticum aestivum) cultivars, Jingdong8 (with erect leaves) and Zhongyou9507 (with horizontal leaves). We analysiced the relation between the direction spectral characteristics and the laeves nitrogen content(LNC). The result showed that the spectral information observed at the 0° angle mainly provided information on the upper canopy and the lower layer had little impact on their spectra. However, the spectral information observed at 30° and 60° angles reflected the whole canopy information and the status of the lower layer of the canopy had great effects on their spectra. Variance analysis indicated that the ear layer of canopy and the topmost leaf blade made greater contributions to CDS. The predicted grain protein content (GPC) model by leaf layers spectra using 0° view angle was the bestwith root mean squares (RMSE) of 0.7500 for Jingdong8 and 0.6461 for Zhongyou9507. The coefficients of determination, R2 between measured and estimated grain protein contents were 0.7467 and 0.7599. Thus, grain protein may be reliably predicted from the leaf layer spectral model.
wheat canopy leaf distribution direction spectra view angle model
Chun-Hua Xiao Shao-Kun Li Ke-Ru Wang Yan-Li Lu Jun-Hua Bai Rui-Zhi Xie Shi-Ju Gao Qiong Wang Fang-Yong Wang
Key Laboratory of Oasis Ecology Agriculture of Xinjiang Construction Crop/Center of Crop High-Yield Key Laboratory of Oasis Ecology Agriculture of Xinjiang Construction Crop/Center of Crop High-Yield Key Laboratory of Oasis Ecology Agriculture of Xinjiang Construction Crop/Center of Crop High-Yield Institute of Crop Science, Chinese Academy of Agricultural Sciences / National Key Facility for Crop Key Laboratory of Oasis EcologyAgriculture of Xinjiang Construction Crop/Center of Crop High-Yield R