- 作者: CHWEN-MING YANG AND CHING-HUAN CHENG
- 中文摘要: Spectral characteristics of rice plants at various levels of infestation by the brown planthopper, Nilaparvata lugens (Stal), (Homoptera:Delphacidae), in the early grain-filling stage were measured and analyzed using a spectroradiometer. Plant damage was classified into six scales, i.e., 0 (CK), 1, 3, 5, 7 and 9, based on the scale of infestation displayed on the surfaces of plant parts. Results showed that mean curves of reflectance spectra (350 - 1800 nm) from different scales of insect infestation were clearly differentiated, especially in the region of 737 - 925 nm, where reflectance was in the order of severity. There were significant differences in reflectance among infestations at wavelengths of 755 and 890 nm particularly. Spectral parameters such as the normalized difference vegetation index (NDVI) and cumulative reflectance may also be used to discriminate levels of infestation. Twelve wavelengths from apparent peaks and valleys of individual spectra were selected as characteristic wavelengths making up the spectral signature of each infestation.
- 英文摘要: --
- 中文關鍵字: spectral characteristics, spectral signature, rice, brown planthopper (Nilaparvata lugens), reflectance spectrum
- 英文關鍵字: --