PMID- 32829161 OWN - NLM STAT- MEDLINE DCOM- 20210514 LR - 20210514 IS - 1873-3557 (Electronic) IS - 1386-1425 (Linking) VI - 243 DP - 2020 Dec 15 TI - Study on terahertz spectrum analysis and recognition modeling of common agricultural diseases. PG - 118820 LID - S1386-1425(20)30799-X [pii] LID - 10.1016/j.saa.2020.118820 [doi] AB - Diseases are critical factors that affect the yield and quality of crops. Therefore, it is of great research value to develop rapid and quantitative methods for identification of common agricultural diseases. This exploratory study involved data analysis of common fungal pathogens using identification modeling based on terahertz spectrum technology. The selected pathogens were Physalospora piricola, Erysiphe cichoracearum, and Botrytis cinerea, which are common fungal pathogens that cause apple ring rot, cucumber powdery mildew, and grape gray mold blight, respectively. Taking polyethylene as the control, the terahertz time-domain spectra, and frequency-domain spectra of samples of the three pathogens were both measured. The absorption and refraction characteristics of these samples in the range of 0.1-2.0 THz were calculated and analyzed, and samples were then divided using the KS algorithm. Terahertz spectrum-image data blocks of the pathogen samples were preprocessed, and the dimensions of data were reduced using non-local mean filtering and the SPA algorithm, respectively. K-nearest neighbors (KNN), support vector machine (SVM), and BP neural network (BPNN), and other algorithms were used for analysis of terahertz images at characteristic frequencies, and for investigating the identification model. The model was quantitatively evaluated, and its imaging visualization was studied. The results suggest that there are significant differences among P. piricola, E. cichoracearum, and B. cinerea in absorption and refraction in the terahertz band. SVM modeling identification results of the three pathogens at the frequency of 1.376 THz were satisfactory, with an R(p) of 0.9649, RMSEP of 0.0273, and a high (93.8212%) comprehensive evaluation index F1-score, and a clearly identifiable visualization effect. This study demonstrated the potential of terahertz spectroscopy to be used for identification of common crop pathogens and has provided technical references for the rapid diagnosis and early warning of agricultural diseases. CI - Copyright (c) 2020 Elsevier B.V. All rights reserved. FAU - Li, Bin AU - Li B AD - Beijing Research Center of Intelligent Equipment for Agriculture, Beijing, PR China; Key Laboratory of Quantitative Remote Sensing in Agriculture, Ministry of Agriculture, PR China. Electronic address: Lib@nercita.org.cn. FAU - Zhang, Dianpeng AU - Zhang D AD - Beijing Academy of Forestry and Agriculture Sciences, Beijing, PR China. FAU - Shen, Yin AU - Shen Y AD - Beijing Research Center of Intelligent Equipment for Agriculture, Beijing, PR China; Key Laboratory of Quantitative Remote Sensing in Agriculture, Ministry of Agriculture, PR China. LA - eng PT - Journal Article DEP - 20200811 PL - England TA - Spectrochim Acta A Mol Biomol Spectrosc JT - Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy JID - 9602533 RN - Botrytis cinerea SB - IM MH - Botrytis MH - Neural Networks, Computer MH - Spectrum Analysis MH - Support Vector Machine MH - *Terahertz Spectroscopy OTO - NOTNLM OT - Crop pathogen OT - Identification OT - Imaging OT - Spectroscopy OT - Terahertz OT - Terahertz data-cube COIS- Declaration of competing interest The authors declare no conflict of interest. EDAT- 2020/08/24 06:00 MHDA- 2021/05/15 06:00 CRDT- 2020/08/24 06:00 PHST- 2020/07/20 00:00 [received] PHST- 2020/08/02 00:00 [revised] PHST- 2020/08/07 00:00 [accepted] PHST- 2020/08/24 06:00 [pubmed] PHST- 2021/05/15 06:00 [medline] PHST- 2020/08/24 06:00 [entrez] AID - S1386-1425(20)30799-X [pii] AID - 10.1016/j.saa.2020.118820 [doi] PST - ppublish SO - Spectrochim Acta A Mol Biomol Spectrosc. 2020 Dec 15;243:118820. doi: 10.1016/j.saa.2020.118820. Epub 2020 Aug 11.