Exploring UAV narrow-band hyperspectral indices and crop functional traits derived from radiative transfer models to detect wheat powdery mildew

The wheat powdery mildew (WPM) is one of the most severe crop diseases worldwide, affecting wheat growth and causing yield losses. The WPM was a bottom-up disease that caused the loss of cell integrity, leaf wilting, and canopy structure damage with these symptoms altering the crop’s functional trai...

Full description

Saved in:
Bibliographic Details
Main Authors: Yang Liu, Xiaoyang Ma, Lulu An, Hong Sun, Fangkui Zhao, Xiaojing Yan, Yuntao Ma, Minzan Li
Format: Article
Language:English
Published: Elsevier 2025-07-01
Series:International Journal of Applied Earth Observations and Geoinformation
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S1569843225002742
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850209083814051840
author Yang Liu
Xiaoyang Ma
Lulu An
Hong Sun
Fangkui Zhao
Xiaojing Yan
Yuntao Ma
Minzan Li
author_facet Yang Liu
Xiaoyang Ma
Lulu An
Hong Sun
Fangkui Zhao
Xiaojing Yan
Yuntao Ma
Minzan Li
author_sort Yang Liu
collection DOAJ
description The wheat powdery mildew (WPM) is one of the most severe crop diseases worldwide, affecting wheat growth and causing yield losses. The WPM was a bottom-up disease that caused the loss of cell integrity, leaf wilting, and canopy structure damage with these symptoms altering the crop’s functional traits (CFT) and canopy spectra. The unmanned aerial vehicle (UAV)-based hyperspectral analysis became a mainstream method for WPM detection. However, the CFT changes experienced by infected wheats, the relationship between CFT and canopy spectra, and their role in WPM detection remained unclear, which might blur the understanding for the WPM infection. Therefore, this study aimed to propose a new method that considered the role of CFT for detecting WPM and estimating disease severity. The UAV hyperspectral data used in this study were collected from the Plant Protection Institute’s research demonstration base, Xinxiang city, China, covering a broad range of WPM severity (0–85 %) from 2022 to 2024. The potential of eight CFT [leaf structure parameter (N), leaf area index (LAI), chlorophyll a + b content (Cab), carotenoids (Car), Car/Cab, anthocyanins (Ant), canopy chlorophyll content (CCC) and average leaf angle (Deg)] obtained from a hybrid method combining a radiative transfer model and random forest (RF) and fifty-five narrow-band hyperspectral indices (NHI) was explored in WPM detection. Results indicated that N, Cab, Ant, Car, LAI, and CCC showed a decreasing trend with increasing disease severity, while Deg and Car/Cab exhibited the opposite pattern. There were marked differences between healthy samples and the two higher infection levels (moderate and severe infection) for Cab, Car, LAI, Deg, CCC, and Car/Cab. N and Ant only showed significant differences between the healthy samples and the highest infection level (severe infection). As Cab, Car, and Ant decreased, the spectral reflectance in the visible light region increased. The decrease in N and LAI was accompanied by a reduction in reflectance across the entire spectral range and the near-infrared area, which was exactly the opposite of Deg. The introduction of CFT greatly improved the accuracy of the WPM severity estimation model with R2 of 0.92. Features related to photosynthesis, pigment content, and canopy structure played a decisive role in estimating WPM severity. Also, results found that the feature importance showed a remarkable interchange as increasing disease levels. Using features that described canopy structure changes, such as optimized soil adjusted vegetation index, LAI, visible atmospherically resistant indices, and CCC, the mild infection stage of this disease was most easily distinguished from healthy samples. In contrast, most severe impacts of WPM were best characterized by features related to photosynthesis (e.g., photochemical reflectance index 515) and pigment content (e.g., normalized phaeophytinization index). This study help deepen the understanding of symptoms and spectral responses caused by WPM infection.
format Article
id doaj-art-265bf84cb0b64c298a69c9ba3d5bc6b7
institution OA Journals
issn 1569-8432
language English
publishDate 2025-07-01
publisher Elsevier
record_format Article
series International Journal of Applied Earth Observations and Geoinformation
spelling doaj-art-265bf84cb0b64c298a69c9ba3d5bc6b72025-08-20T02:10:06ZengElsevierInternational Journal of Applied Earth Observations and Geoinformation1569-84322025-07-0114110462710.1016/j.jag.2025.104627Exploring UAV narrow-band hyperspectral indices and crop functional traits derived from radiative transfer models to detect wheat powdery mildewYang Liu0Xiaoyang Ma1Lulu An2Hong Sun3Fangkui Zhao4Xiaojing Yan5Yuntao Ma6Minzan Li7Key Lab of Smart Agriculture System, Ministry of Education, China Agricultural University, Beijing 100083, ChinaKey Lab of Smart Agriculture System, Ministry of Education, China Agricultural University, Beijing 100083, ChinaKey Lab of Smart Agriculture System, Ministry of Education, China Agricultural University, Beijing 100083, ChinaKey Lab of Smart Agriculture System, Ministry of Education, China Agricultural University, Beijing 100083, China; Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing 100083, China; Corresponding author.State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, ChinaState Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, ChinaCollege of Land Science and Technology, China Agricultural University, Beijing 100193, ChinaKey Lab of Smart Agriculture System, Ministry of Education, China Agricultural University, Beijing 100083, China; Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing 100083, ChinaThe wheat powdery mildew (WPM) is one of the most severe crop diseases worldwide, affecting wheat growth and causing yield losses. The WPM was a bottom-up disease that caused the loss of cell integrity, leaf wilting, and canopy structure damage with these symptoms altering the crop’s functional traits (CFT) and canopy spectra. The unmanned aerial vehicle (UAV)-based hyperspectral analysis became a mainstream method for WPM detection. However, the CFT changes experienced by infected wheats, the relationship between CFT and canopy spectra, and their role in WPM detection remained unclear, which might blur the understanding for the WPM infection. Therefore, this study aimed to propose a new method that considered the role of CFT for detecting WPM and estimating disease severity. The UAV hyperspectral data used in this study were collected from the Plant Protection Institute’s research demonstration base, Xinxiang city, China, covering a broad range of WPM severity (0–85 %) from 2022 to 2024. The potential of eight CFT [leaf structure parameter (N), leaf area index (LAI), chlorophyll a + b content (Cab), carotenoids (Car), Car/Cab, anthocyanins (Ant), canopy chlorophyll content (CCC) and average leaf angle (Deg)] obtained from a hybrid method combining a radiative transfer model and random forest (RF) and fifty-five narrow-band hyperspectral indices (NHI) was explored in WPM detection. Results indicated that N, Cab, Ant, Car, LAI, and CCC showed a decreasing trend with increasing disease severity, while Deg and Car/Cab exhibited the opposite pattern. There were marked differences between healthy samples and the two higher infection levels (moderate and severe infection) for Cab, Car, LAI, Deg, CCC, and Car/Cab. N and Ant only showed significant differences between the healthy samples and the highest infection level (severe infection). As Cab, Car, and Ant decreased, the spectral reflectance in the visible light region increased. The decrease in N and LAI was accompanied by a reduction in reflectance across the entire spectral range and the near-infrared area, which was exactly the opposite of Deg. The introduction of CFT greatly improved the accuracy of the WPM severity estimation model with R2 of 0.92. Features related to photosynthesis, pigment content, and canopy structure played a decisive role in estimating WPM severity. Also, results found that the feature importance showed a remarkable interchange as increasing disease levels. Using features that described canopy structure changes, such as optimized soil adjusted vegetation index, LAI, visible atmospherically resistant indices, and CCC, the mild infection stage of this disease was most easily distinguished from healthy samples. In contrast, most severe impacts of WPM were best characterized by features related to photosynthesis (e.g., photochemical reflectance index 515) and pigment content (e.g., normalized phaeophytinization index). This study help deepen the understanding of symptoms and spectral responses caused by WPM infection.http://www.sciencedirect.com/science/article/pii/S1569843225002742Wheat powdery mildewUnmanned aerial vehicleRadiative transfer modelCrop functional traitsNarrow-band hyperspectral indices
spellingShingle Yang Liu
Xiaoyang Ma
Lulu An
Hong Sun
Fangkui Zhao
Xiaojing Yan
Yuntao Ma
Minzan Li
Exploring UAV narrow-band hyperspectral indices and crop functional traits derived from radiative transfer models to detect wheat powdery mildew
International Journal of Applied Earth Observations and Geoinformation
Wheat powdery mildew
Unmanned aerial vehicle
Radiative transfer model
Crop functional traits
Narrow-band hyperspectral indices
title Exploring UAV narrow-band hyperspectral indices and crop functional traits derived from radiative transfer models to detect wheat powdery mildew
title_full Exploring UAV narrow-band hyperspectral indices and crop functional traits derived from radiative transfer models to detect wheat powdery mildew
title_fullStr Exploring UAV narrow-band hyperspectral indices and crop functional traits derived from radiative transfer models to detect wheat powdery mildew
title_full_unstemmed Exploring UAV narrow-band hyperspectral indices and crop functional traits derived from radiative transfer models to detect wheat powdery mildew
title_short Exploring UAV narrow-band hyperspectral indices and crop functional traits derived from radiative transfer models to detect wheat powdery mildew
title_sort exploring uav narrow band hyperspectral indices and crop functional traits derived from radiative transfer models to detect wheat powdery mildew
topic Wheat powdery mildew
Unmanned aerial vehicle
Radiative transfer model
Crop functional traits
Narrow-band hyperspectral indices
url http://www.sciencedirect.com/science/article/pii/S1569843225002742
work_keys_str_mv AT yangliu exploringuavnarrowbandhyperspectralindicesandcropfunctionaltraitsderivedfromradiativetransfermodelstodetectwheatpowderymildew
AT xiaoyangma exploringuavnarrowbandhyperspectralindicesandcropfunctionaltraitsderivedfromradiativetransfermodelstodetectwheatpowderymildew
AT luluan exploringuavnarrowbandhyperspectralindicesandcropfunctionaltraitsderivedfromradiativetransfermodelstodetectwheatpowderymildew
AT hongsun exploringuavnarrowbandhyperspectralindicesandcropfunctionaltraitsderivedfromradiativetransfermodelstodetectwheatpowderymildew
AT fangkuizhao exploringuavnarrowbandhyperspectralindicesandcropfunctionaltraitsderivedfromradiativetransfermodelstodetectwheatpowderymildew
AT xiaojingyan exploringuavnarrowbandhyperspectralindicesandcropfunctionaltraitsderivedfromradiativetransfermodelstodetectwheatpowderymildew
AT yuntaoma exploringuavnarrowbandhyperspectralindicesandcropfunctionaltraitsderivedfromradiativetransfermodelstodetectwheatpowderymildew
AT minzanli exploringuavnarrowbandhyperspectralindicesandcropfunctionaltraitsderivedfromradiativetransfermodelstodetectwheatpowderymildew