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Detecting Sorghum Plant and Head Features from Multispectral UAV Imagery

Plant Phenomics 2021年第1期3卷 337-350页

作者： Yan Zhao bangyou Zheng Scott CChapman Kenneth Laws barbara George-Jaeggli Graeme LHammer David RJordan Andries B.Potgieter The University of Queensland Queensland Alliance for Agriculture and Food InnovationCentre for Crop ScienceGattonQueensland 4343Australia CSIRO Agriculture and Food St.LuciaQueensland 4072Australia The University of Queensland School of Agriculture and Food SciencesSt.LuciaQueensland 4072Australia Department of Agriculture and Fisheries Agri-Science QueenslandWarwickQueensland 4370Australia

In plant breeding,unmanned aerial vehicles(UAVs)carrying multispectral cameras have demonstrated increasing utility for high-throughput phenotyping(HTP)to aid the interpretation of genotype and environment effects on morphological,biochemical,and physiological traits.A key constraint remains the reduced resolution and quality extracted from“stitched”mosaics generated from UAV missions across large areas.This can be addressed by generating high-quality reflectance data from a single nadir image per plot.In this study,a pipeline was developed to derive reflectance data from raw multispectral UAV images that preserve the original high spatial and spectral resolutions and to use these for phenotyping applications.Sequential steps involved(i)imagery calibration,(ii)spectral band alignment,(iii)backward calculation,(iv)plot segmentation,and(v)application.Each step was designed and optimised to estimate the number of plants and count sorghum heads within each breeding plot.Using a derived nadir image of each plot,the coefficients of determination were 0.90 and 0.86 for estimates of the number of sorghum plants and heads,respectively.Furthermore,the reflectance information acquired from the different spectral bands showed appreciably high discriminative ability for sorghum head colours(i.e.,red and white).Deployment of this pipeline allowed accurate segmentation of crop organs at the canopy level across many diverse field plots with minimal training needed from machine learning approaches.

关键词： breeding backward Plant

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Challenges and opportunities in remote sensing-based crop monitoring: a review

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National Science Review 2023年第4期10卷 203-219页

作者： bingfang Wu Miao Zhang Hongwei Zeng Fuyou Tian Andries B.Potgieter Xingli Qin Nana Yan Sheng Chang Yan Zhao Qinghan Dong Vijendra boken Dmitry Plotnikov Huadong Guo Fangming Wu Hang Zhao bart Deronde Laurent Tits Evgeny Loupian State Key Laboratory of Remote Sensing Science Aerospace Information Research Institute Chinese Academy of Sciences School of Resources and Environment University of Chinese Academy of Sciences Executive Committee of Group on Earth Observations Global Agricultural Monitoring (GEOGLAM) Queensland Alliance for Agriculture and Food Innovation The University of Queensland Department of Remote Sensing Flemish Institute of Technological Research Department of Geography and Earth Science University of Nebraska-Kearney Department of Satellite Monitoring Technologies Space Research Institute of Russian Academy of Sciences

building a more resilient food system for sustainable development and reducing uncertainty in global food markets both require concurrent and near-real-time and reliable crop information for decision making.Satellite-driven crop monitoring has become a main method to derive crop information at local, regional,and global scales by revealing the spatial and temporal dimensions of crop growth status and production.However, there is a lack of quantitative, objective, and robust methods to ensure the reliability of crop information, which reduces the applicability of crop monitoring and leads to uncertain and undesirable consequences. In this paper, we review recent progress in crop monitoring and identify the challenges and opportunities in future efforts. We find that satellite-derived metrics do not fully capture determinants of crop production and do not quantitatively interpret crop growth status; the later can be advanced by integrating effective satellite-derived metrics and new onboard sensors. We have identified that ground data accessibility and the negative effects of knowledge-based analyses are two essential issues in crop monitoring that reduce the applicability of crop monitoring for decisions on food security. Crowdsourcing is one solution to overcome the restrictions of ground-truth data accessibility. We argue that user participation in the complete process of crop monitoring could improve the reliability of crop information.Encouraging users to obtain crop information from multiple sources could prevent unconscious biases.Finally, there is a need to avoid conflicts of interest in publishing publicly available crop information.

关键词： crop monitoring crop condition crop production Ground data Remote Sensing

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From Prototype to Inference:A Pipeline to Apply Deep Learning in Sorghum Panicle Detection

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Plant Phenomics 2023年第1期5卷 94-109页

作者： Chrisbin James Yanyang Gu andries potgieter Etienne David Simon Madec Wei Guo Frédéric baret Anders Eriksson Scott Chapman School of Agriculture and Food Sciences The University of QueenslandBrisbaneAustralia School of Information Technology and Electrical Engineering The University of QueenslandBrisbaneAustralia Queensland Alliance for Agriculture and Food Innovation The University of QueenslandBrisbaneAustralia Arvalis Institut du VégétalParisFrance Graduate School of Agricultural and Life Sciences The University of TokyoTokyoJapan Institut National de la Recherche Agronomique ParisFrance

Head(panicle)density is a major component in understanding crop yield,especially in crops that produce variable numbers of tillers such as sorghum and wheat.Use of panicle density both in plant breeding and in the agronomy scouting of commercial crops typically relies on manual counts observation,which is an inefficient and tedious process.because of the easy availability of red–green–blue images,machine learning approaches have been applied to replacing manual counting.However,much of this research focuses on detection per se in limited testing conditions and does not provide a general protocol to utilize deep-learning-based counting.In this paper,we provide a comprehensive pipeline from data collection to model deployment in deep-learning-assisted panicle yield estimation for sorghum.This pipeline provides a basis from data collection and model training,to model validation and model deployment in commercial fields.Accurate model training is the foundation of the pipeline.However,in natural environments,the deployment dataset is frequently different from the training data(domain shift)causing the model to fail,so a robust model is essential to build a reliable solution.Although we demonstrate our pipeline in a sorghum field,the pipeline can be generalized to other grain species.Our pipeline provides a high-resolution head density map that can be utilized for diagnosis of agronomic variability within a field,in a pipeline built without commercial software.

关键词： crops breeding utilize

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Estimating Photosynthetic Attributes from High-Throughput Canopy Hyperspectral Sensing in Sorghum

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Plant Phenomics 2022年第1期4卷 324-341页

作者： Xiaoyu Zhi Sean Reynolds Massey-Reed Alex Wu andries potgieter Andrew borrell Colleen Hunt David Jordan Yan Zhao Scott Chapman Graeme Hammer barbara George-Jaeggli The University of Queensland Queensland Alliance for Agriculture and Food Innovation(QAAFI)Hermitage Research FacilityWarwickQLDAustralia The University of Queensland Queensland Alliance for Agriculture and Food Innovation(QAAFI)St LuciaQLDAustralia The University of Queensland Queensland Alliance for Agriculture and Food Innovation(QAAFI)GattonQLDAustralia Agri-Science Queensland Department of Agriculture and Fisheries(DAF)Hermitage Research FacilityWarwickQLDAustralia School of Agriculture and Food Sciences The University of QueenslandGattonQLDAustralia

Sorghum,a genetically diverse C_(4) cereal,is an ideal model to study natural variation in photosynthetic capacity.Specific leaf nitrogen(SLN)and leaf mass per leaf area(LMA),as well as,maximal rates of Rubisco carboxylation(V cmax),phosphoenolpyruvate(PEP)carboxylation(V pmax),and electron transport(J max),quantified using a C_(4) photosynthesis model,were evaluated in two field-grown training sets(n=169 plots including 124 genotypes)in 2019 and 2020.

关键词： capacity maximal Sorghum

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Dust Suppression on Open Pit Drill Rigs--Case Study from Skorpion Zinc Mine

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Journal of Earth Science and Engineering 2015年第8期5卷 512-519页

作者： Stefanus andries Jakobus potgieter Johannes Jacobus Labuschagne du Plessis Skorpion Zinc Mine Rosh Pinah Namibia Department of Mining Engineering Faculty of Engineering Build Environment and Information Technology University oJPretoria Pretoria 0028 South Africa

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High-Throughput Phenotyping of Dynamic Canopy Traits Associated with Stay-Green in Grain Sorghum

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Plant Phenomics 2020年第1期2卷 269-278页

作者： J.D.Liedtke C.H.Hunt b.George-Jaeggli K.Laws J.Watson A.b.potgieter A.Cruickshank D.R.Jordan University of Hohenheim 70593 StuttgartGermany Agri-Science Queensland Department of Agriculture and FisheriesWarwickQLD 4370Australia Queensland Alliance for Agriculture and Food Innovation The University of QueenslandWarwickQLD 4370Australia Queensland Alliance for Agriculture and Food Innovation The University of QueenslandGatton CampusToowoomba QLD 4343Australia

Drought is a recurring phenomenon that puts crop yields at risk and threatens the livelihoods of many people around the globe.Stay-green is a drought adaption phenotype found in sorghum and other cereals.Plants expressing this phenotype show less drought-induced senescence and maintain functional green leaves for longer when water limitation occurs during grain fill,conferring benefits in both yield per se and harvestability.The physiological causes of the phenotype are postulated to be water saving through mechanisms such as reduced canopy size or access to extra water through mechanisms such as deeper roots.In sorghum breeding programs,stay-green has traditionally been assessed by comparing visual scores of leaf senescence either by identifying final leaf senescence or by estimating rate of leaf senescence.In this study,we compared measurements of canopy dynamics obtained from remote sensing on two sorghum breeding trials to stay-green values(breeding values)obtained from visual leaf senescence ratings in multienvironment breeding trials to determine which components of canopy development were most closely linked to the stay-green phenotype.Surprisingly,canopy size as estimated using preflowering canopy parameters was weakly correlated with stay-green values for leaf senescence while postflowering canopy parameters showed a much stronger association with leaf senescence.Our study suggests that factors other than canopy size have an important role in the expression of a stay-green phenotype in grain sorghum and further that the use of UAVs with multispectral sensors provides an excellent way of measuring canopy traits of hundreds of plots grown in large field trials.

关键词： breeding drought hundreds

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Exploring the Potential Impacts of Climate Variability on Spring Wheat Yield with the APSIM Decision Support Tool

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Agricultural Sciences 2015年第7期6卷 686-698页

作者： Louis Kouadio Nathaniel Newlands andries potgieter Greg McLean Harvey Hill International Centre for Applied Climate Sciences University of Southern Queensland Toowoomba Australia Science and Technology (S & T) Environmental Health Agriculture and Agri-Food Canada (AAFC) Lethbridge Research Centre Lethbridge Canada Queensland Alliance for Agriculture and Food Innovation University of Queensland Toowoomba Australia Queensland Department of Agriculture and Fisheries Toowoomba Australia National Agroclimate Information Service S & T-AAFC Saskatoon Canada

Assessing the impacts of climate variability on agricultural productivity at regional, national or global scale is essential for defining adaptation and mitigation strategies. We explore in this study the potential changes in spring wheat yields at Swift Current and Melfort, Canada, for different sowing windows under projected climate scenarios (i.e., the representative concentration pathways, RCP4.5 and RCP8.5). First, the APSIM model was calibrated and evaluated at the study sites using data from long term experimental field plots. Then, the impacts of change in sowing dates on final yield were assessed over the 2030-2099 period with a 1990-2009 baseline period of observed yield data, assuming that other crop management practices remained unchanged. Results showed that the performance of APSIM was quite satisfactory with an index of agreement of 0.80, R2 of 0.54, and mean absolute error (MAE) and root mean square error (RMSE) of 529 kg/ha and 1023 kg/ha, respectively (MAE = 476 kg/ha and RMSE = 684 kg/ha in calibration phase). Under the projected climate conditions, a general trend in yield loss was observed regardless of the sowing window, with a range from ?-24% to -94% depending on the site and the RCP, and noticeable losses during the 2060s and beyond (increasing CO2 effects being excluded). Smallest yield losses obtained through earlier possible sowing date (i.e., mid-April) under the projected future climate suggested that this option might be explored for mitigating possible adverse impacts of climate variability. Our findings could therefore serve as a basis for using APSIM as a decision support tool for adaptation/mitigation options under potential climate variability within Western Canada.

关键词： Climate Variability APSIM Crop Modelling Spring Wheat

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Parametric study of spark plasma sintering of Al_(20)Cr_(20)Fe_(25)Ni_(25)Mn_(10) high entropy alloy with improved microhardness and corrosion

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International Journal of Minerals,Metallurgy and Materials 2022年第1期29卷 119-127页

作者： andries Mthisi Nicholus Malatji A.Patricia I.Popoola L.Rudolf Kanyane Department of Chemical Metallurgical and Materials EngineeringTshwane University of TechnologyP.M.B.X680PretoriaSouth Africa

Multicomponent Al_(20)Cr_(20)Fe_(25)Ni_(25)Mn_(10) alloys were synthesized using spark plasma sintering at different temperatures(800,900,and 1000℃)and holding times(4,8,and 12 min)to develop a high entropy alloy(HEA).The characteristics of spark plasma-synthesized(SPSed)alloys were experimentally explored through investigation of microstructures,microhardness,and corrosion using scanning electron microscopy coupled with energy dispersive spectroscopy(EDS),Vickers microhardness tester,and potentiodynamic polarization,respectively.Xray diffraction(XRD)characterization was employed to identify the phases formed on the developed alloys.The EDS results revealed that the alloys consisted of elements selected in this work irrespective of varying sintering parameters.The XRD,EDS,and scanning electron microscopy collectively provided evidence that the fabricated alloys were characterized by globular microstructures exhibiting face-centered cubic phase,which was formed on a basis of solid solution mechanism.This finding implies that the SPSed alloy showed the features of HEAs.The alloy produced at 1000℃ and holding time of 12 min portrayed an optimal microhardness of HV 447.97,but the value decreased to HV 329.47 after heat treatment.The same alloy showed an outstanding corrosion resistance performance.The increase in temperature resulted in an Al_(20)Cr_(20)Fe_(25)Ni_(25)Mn_(10) alloy with superior density,microhardness,and corrosion resistance over the other alloys developed at different parameters.

关键词： high entropy alloy spark plasma sintering microhardness corrosion

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Systematic characterization of cleanroom-free fabricated macrovalves,demonstrating pumps and mixers for automated fluid handling tuned for organ-on-chip applications

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Microsystems & Nanoengineering 2022年第3期8卷 163-176页

作者： Elsbeth G.b.M.bossink Anke R.Vollertsen Joshua T.Loessberg-Zahl andries D.van der Meer Loe l.Segerink Mathieu Odijk bIOs Lab on a Chip Group MESA+instituteTechnical Medical CenterMax Planck Institute for Complex Fluid DynamicsUniversity of TwenteEnschedeThe Netherlands Applied Stem Cell Technologies Group Technical Medical CenterUniversity of TwenteEnschedeThe Netherlands

Integrated valves enable automated control in microfuidic systems,as they can be applied for mixing,pumping and compartmentalization purposes.Such automation would be highly valuable for applications in organ-on-chip(OoC)systems.However,OoC systems typically have channel dimensions in the range of hundreds of micrometers,which is an order of magnitude larger than those of typical microfluidic valves.The most-used fabrication process for integrated,normally open polydimethylsiloxane(PDMS)valves requires a reflow photoresist that limits the achievable channel height.In addition,the low stroke volumes of these valves make it challenging to achieve flow rates of microliters per minute,which are typically required in OoC systems.Herein,we present a mechanical'macrovalve'fabricated by multilayer soft lithography using micromilled direct molds.We demonstrate that these valves can close off rounded channels of up to 700μm high and 1000μm wide.Furthermore,we used these macrovalves to create a peristaltic pump with a pumping rate of up to 48μL/min and a mixing and metering device that can achieve the complete mixing of a volume of 6.4μL within only 17 s.An initial cell culture experiment demonstrated that a device with integrated macrovalves is biocompatible and allows the cell culture of endothelial cells over multiple days under continuous perfusion and automated medium refreshment.

关键词： pumping mixer pump

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Elevated skin autofluorescence is strongly associated with foot ulcers in patients with diabetes: a cross-sectional, observational study of Chinese subjects

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Journal of Zhejiang University-Science b(biomedicine & biotechnology) 2012年第5期13卷 372-377页

作者： Hang HU Chun-mao HAN Xin-lei HU Wan-lan YE Wen-juan HUANG andries J.SMIT Department of burns and Wound Center the Second Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhou 310009China Department of Endocrine and Diabetic Center the Seeond Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhou 310009China Departrnent of Internal Medicine University Medical Center Groningen9700 RB Groningenthe Netherlands

Objective: This study was designed to evaluate the association between skin autofluorescence (AF), an indicator of advanced glycation end-products (AGEs), and foot ulcers in subjects with diabetes. Methods: In this study, 195 Chinese diabetic subjects were examined. Their feet were examined regardless of whether an ulcer was present or not. Skin AF was measured with an AGE reader. Demographic characteristics and blood data were recorded. Results: The mean values of skin AF were 2.29±0.47 for subjects without foot ulcers, and 2.80±0.69 for those with foot ulcers, a significant difference (Pbetes. After adjusting for these factors, multivariate logistic regression showed that skin AF was independently associated with foot ulcerations. Conclusions: Skin AF is independently associated with diabetic foot ulcerations. It might be a useful screening method for foot ulceration risk of diabetic patients.

关键词：自体荧光糖尿病溃疡皮肤足部患者 logistic回归分析中国

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