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Testing a bell-shaped function for estimation of fully expanded leaf area in modern maize under potential production conditions

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The Crop Journal 2018年第5期6卷 527-537页

作者： Xiaoxing Zhen Hui Shao Weina Zhang Weige Huo William David Batchelor Peng Hou Enli Wang Guohua Mi Yuxin Miao Haigang Li Fusuo Zhang College of Resources and Environmental Sciences China Agricultural UniversityBeijing 100193China Biosystems Engineering Department Auburn UniversityAuburnAL 36849USA Institute of Crop Sciences Chinese Academy of Agricultural SciencesKey Laboratory of Crop Physiology and EcologyMinistry of AgricultureBeijing 100081China CSIRO Agriculture Flagship CanberraACT 2601Australia Department of Soil Water and ClimateMinnesota UniversitySt.PaulMN 55108USA

Accurate leaf area simulation is critical for the performance of crop growth models. area of fully expanded individual leaves of maize hybrids released before 1995 (defined as old hybrids) has been simulated using a bell-shaped function (BSF) and the relationship between its parameters and total leaf number (TLNO). However, modern high-yielding maize hybrids show different canopy architectures. The function parameters calibrated for old hybrids will not accurately represent modern hybrids. In this study, we evaluated these functions using a dataset including old and modern hybrids that have been widely planted in China in recent years. Maximum individual leaf area (Y_0) and corresponding leaf position (X_0) were not predicted well by TLNO (R^2= 0.56 and R^2= 0.70) for modern hybrids. Using recalibrated shape parameters a and b with values of Y_0 and X_0 for modern hybrids, the BSF accurately predicted individual leaf area (R^2= 0.95–0.99) and total leaf area of modern hybrids (R^2= 0.98). The results show that the BSF is still a robust way to predict the fully expanded leaf area of maize when parameters a and b are modified and Y_0 and X_0 are fitted. Breeding programs have led to increases in TLNO of maize but have not altered Y_0 and X_0, reducing the correlation between Y_0, X_0, and TLNO. For modern hybrids, the values of Y_0 and X_0 are hybrid-specific. Modern hybrids tend to have less-negative values of parameter a and more-positive values of parameter b in the leaf profile. Growth conditions, such as plant density and environmental conditions, also affect the fully expanded leaf area but were not considered in the original published equations. Thus, further research is needed to accurately estimate values of Y_0 and X_0 of individual modern hybrids to improve simulation of maize leaf area in crop growth models.

关键词： Hybrids leaf area leaf number Plant density Environmental conditions

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Model-based in-situ measurement of pakchoi leaf area

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International Journal of Agricultural and Biological Engineering 2015年第4期8卷 35-42页

作者： Gong Liang Chen Ran Zhao Yuanshen Liu Chengliang School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

leaf area measurement is of great significance in plant growth process *** poses challenges to perform an unattended in-situ measurement,arising from quantifying the 3-dimensional pakchoi leaf *** non-destructive measurement techniques,which usually take its projection on the horizon plane of the leaf area,inevitably cause considerable measurement *** order to improve the measurement precision for leaf area,the exemplar pakchoi leaf was modeled as a complete or a piecewise spatial plane to approximate the actual leaf surface,and a machine-vision based ad hoc measuring platform was developed to conduct the in-situ ***,the leaf image was captured by a stereo vision system and segmented via a semi-automatic process to obtain its projective area and spatial inclination ***,pakchoi leaves were modeled as spatial surfaces regarding to their projected ***,leaf areas were calculated according to the established planar spatial model,acquired inclination angles and projective *** experimental comparison among the lattice-based monotype method,projection method,and the model-based method,whose results are denoted as MA,PA,and EA respectively,showed that the proposed framework could simultaneously meet the accuracy and non-destructive measurement *** constructed platform also provided a cost-effective semi-automatic measurement approach for continuously in-situ monitoring of pakchoi growth during its whole cultivation *** is further suggested from the experimental results that the proposed methodology can offer a generic measurement solution to various kinds of plant physiological and ecological studies in future researches.

关键词： leaf area in-situ measurement non-destructive measurement stereo vision image processing

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A Computer Program for Automatic Watering Based on Potential Evapotranspiration by Penman Method and Predicted leaf area in Miniature Pot Rose Production

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Agricultural Sciences in China 2010年第3期9卷 370-377页

作者： YU Wen-jin Kitamura Ryo Kato Katsuhiko LI Lian-hua Fukui Hirokazu Agricultural College Guangxi University Nanning 530004 P.R.China The United Graduate School of Agricultural Science Gifu University Gifu 5011193 Japan Faculty of Applied Biological Sciences Gifu University Gifu 5011193 Japan Gifu Prefectural Center for Agricultural Sciences Gifu 5011152 Japan

In this study, we developed a computer program for automatic prediction of watering time point by considering the environmental factors such as solar radiation, air temperature and relative humidity based on the multiple linear regression equation of leaf area and Penman Method. The experiments were carried out for a year in two watering experimental plots, one of which was controlled by pF value, and the other by the computer program. After comparing the results of the two plots, the following findings were obtained. In the computer program plot, the observed and predicted values of both leaf area and evapotranspiration indicated significant correlation at the 1% level, which suggested that the computer program had high prediction accuracy. In addition, no significant difference was observed between the two experimental plots with respects to the plant height, plant diameter, leaf area, leaf number, fresh weight, and dry weight, which demonstrated that the plants in the computer program plot had normal growth. On the other hand, although the number of flower buds and flowering shoots showed higher values at the end of certain cultivations in the computer program plot than those in pF value plot, we proposed that it was due to the effect of cumulative daily solar radiation in the greenhouse, rather than the watering. Thus, we have reached the conclusion that the computer program for automatic prediction of watering time point developed by this study has high applicability in miniature pot rose production.

关键词： automatic watering leaf area miniature pot rose Penman Method program

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Models for Estimation of Single leaf area of Mangrove TreesModels Trees based on leaf Length and Widthbased Width

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湿地科学 2014年第2期12卷 214-219页

作者： LE Tongchao Research Institute of Forest Resource Information Techniques Chinese Academy of Forestry

leaf area is an important parameter for modeling plant growth and physiological *** is very expensive and difficult for measuring leaf area by means of leaf area Meter,therefore,it’s quite necessary to obtain one simple model for estimation of leaf area of mangrove *** models for estimation of leaf area of 3 species of mangrove trees were developed based on leaf length and ***,leaf area(LA),leaf length(L)and width(W)were measured from 450 fresh leaves of major three species of mangrove trees in Zhangjiang Estuary Mangrove National Natural Reserve,Fujian *** actual leaf area of the plant was measured with the help of ArcGIS software and regression model was *** majority of the data(80%)were used for model calibration,and the remaining data(20%)were used for model *** the leaf areas of 3 species of mangrove trees had been significant correlation between L,W,L·W,L2,W2and(L+W)2,so the factors could be constructed into a regression model with leaf *** models for estimation of leaf area selected were significantly(pleaf area and leaf length and *** means of regression analysis,the following models were developed:LA=0.28+0.66L·W(R2=0.980)for Kandelia candel,LA=0.09+0.73L·W(R2=0.983)for Avicennia marina,LA=0.52+0.72L·W(R2=0.990)for Aegiceras corniculatum,*** study provided a simple,reliable and non-destructive method for estimating single leaf *** had a good potential in the functional structural model of mangrove tree.

关键词： mangrove leaf area non-destructive measurement regression analysis

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leaf shape simulation of castor bean and its application in nondestructive leaf area estimation

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International Journal of Agricultural and Biological Engineering 2019年第4期12卷 135-140页

作者： Hailin Wei Xumeng Li Ming Li Huang Huang School of Agronomy Hunan Agricultural UniversityChangsha 410128China Hunan Academy of Forestry Changsha 410004China Hunan Academy of Agricultural Sciences Changsha 410000China

The leaf shape and leaf area measurement are crucial in plant growth *** castor bean leaf is large,palm-shaped with multiple *** leaf shape simulation and leaf area estimation were less *** circular model and nonrectangular hyperbolic model were developed to describe the standard leaf shape of castor bean in this study,providing a model for simulating the leaf shape and a nondestructive way for estimating the leaf area *** addition,a formula was established to estimate the leaf area by the parameter of the standard leaf shape of castor *** on validation results,the circular model fits the landmarks and nonrectangular hyperbolic model fits the lobe margins very *** leaf area was accurately estimated by using the established *** study could provide a theoretical reference for leaf visualization,a nondestructive and easy way to estimate the leaf area for other complex leaves with multiple lobes.

关键词： leaf shape leaf area geometrical characteristics mathematical model image processing plant growth modeling

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The Stimulating Effects of Rewatering on leaf area of Winter Wheat Suffering Water Stress

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Agricultural Sciences in China 2002年第2期1卷 177-183页

作者： LIU Xiao-ying, LUO Yuan-pei and SHI Yuan-chun( Institute of Resources and Environments , China Agricultural University, Beijing 100094 Institute of Agrometeorology, CAAS , Beijing 100081) Institute of Resources and Environments China Agricultural University Beijing 100094 Institute ofAgrometeorology CAAS Beijing 100081

After water stress at various levels and durations at different growth stages, rewatering could greatly stimulate the leaf area development of winter wheat. The results showed that the stimulation effect changed with water stress time, degree and duration. Rewatering under earlier stress had greater stimulation effect on leaf area than that under later stress. Higher stimulation effect was observed under severe water stress than that under moderate stress. Longer duration of stress resulted in low stimulation effect. In spite of the greater stimulation effect under severe and longer stress, the final leaf area in these situations was lower than that under moderate stress and shorter duration. Whenever the stress occurred, the stimulating effect was due to the increase of the leaf area of the tillers. Once the leaf on the main stem emerged during stress period, rewatering had no effect on its size, and consequently its leaf area. The stimulation of rewateirng on leaf area contributed to the final grain yield by 45% under moderate stress, and 67% under severe stress. Although the stimulation partly compensated for the loss during stress, the final leaf area and the grain yield could not reach the level without water stress.

关键词： Water stress Rewatering Winter wheat Stimulation leaf area Yield

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Application of remote sensing,an artificial neural network leaf area model,and a process-based simulation model to estimate carbon storage in Florida slash pine plantations.

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Journal of Forestry Research 2010年第2期21卷 171-176,I0005页

作者： Douglas A.Shoemaker Wendell P.Cropper Jr The Center for Applied Geographical Information Science McEniry 320University of North Carolina-Charlotte9201 University City Blvd.Charlotte School of Forest Resources and Conservation Box 110410University of Florida

Carbon sequestration in forests is of great interest due to concerns about global climate *** storage rates depend on ecosystem fluxes（photosynthesis and ecosystem respiration）,typically quantified as net ecosystem exchange（NEE）.Methods to estimate forest NEE without intensive site sampling are needed to accurately assess rates of carbon sequestration at stand-level and larger *** produced spatially-explicit estimates of NEE for 9 770 ha of slash pine（Pinus elliottii） plantations in North-Central Florida for a single year by coupling remote sensing-based estimates of leaf area index（LAI） with a process-based growth simulation *** estimates produced from a neural-network modeling of ground plot and Landsat TM satellite data had a mean of 1.06（range 0-3.93,including forest edges）.Using the neural network LAI values as inputs,the slash pine simulation model（SPM2） estimates of NEE ranged from-5.52 to 11.06 Mg·ha^-1·a^-1with a mean of 3.47 Mg·ha^-1·a^-1Total carbon storage for the year was 33920 t,or about 3.5 tons per *** estimated LAI and NEE were highly sensitive to fertilization.

关键词： artificial neural network leaf area carbon exchange slash pine NEE forest carbon

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Varietal Difference in leaf Nitrogen Content and leaf area and Their Effects to Ripening Rate During Mature Period of japonica Rice

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Journal of Northeast Agricultural University(English Edition) 1999年第2期6卷 81-88页

作者： LiRong－tian KojimaNobuyoshi 等 AgronomyCollege NortheastAgriculturalUniversityHarbin150030PRC TsukubaInternationalCentre JapanInternationalCooperationAgencyIbaraki305－0074Japan

Employing the pot experiment of the complete random block design with 6 replications,four varieties of japonica rice (Fujisaka 5,Honenwase,Akitakomachi and Taichung 65) were used to study the varietal differences in leaf nitrogen content(LNC) and leaf area during mature period,their relation and effects to the ripening *** results showed that(1) thee were varietal differences in LNC at the heading stage and the LNC decrease rate during the matue period,the high LNC at the heading stage was related to the rapid LNC decrease.(2) There were two phases of the leaf area changing process during the mature period,first was the stable,and second was the decreased *** was varietal difference in the critical time of phase 1 and phase *** hign leaf area in the phase 1 was in relation to the rapid leaf area decrease in the phase *** was not found that there was relation between the leaf quality and quantity.(3)It wa unfavorable to the ripening rate for the high leaf area at the heading stage and the rapid decrease of the leaf area during the mature period.(4)It was put forward that the super high yield rice variety should possess the not very high leaf area and high LNC at the heading stage,slow senescence in the leaf area during the mature period.

关键词： japonica rice leaf area leaf nitrogen content(LNC) mature period variety

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Single leaf area estimation models based on leaf weight of eucalyptus in southern China

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Journal of Forestry Research 2010年第1期21卷 73-76,I0003页

作者：刁军雷相东洪玲霞戎建涛石强中国林业科学研究院资源信息研究所北京100091 深圳职业技术学院深圳518055

leaf area is an important parameter for modeling tree growth and physiological processes of trees. The single young and mature leaf area estimation models of eucalyptus were developed based on leaf fresh weight. In total, leaf area and leaf weight were measured from 455 fresh leaves of 25 trees of eucalyptus in southern China. The majority of the data （80%） were used for model calibration, and the remaining data （20%） were used for model validation. The linear, compound and power models were tested. Based on goodness of fit, prediction ability and residual performance, we found that linear and power models could best describe the relationship between leaf area and weight for young leaf and mature leaf, respectively. The study provides a simple and reliable method for estimating single-leaf area, which has a good potential in the functional- structural model of eucalyptus.

关键词： eucalyptus leaf area leaf weight allometric model

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Measurement of Tomato leaf area Using Computer Image Processing Technology

Measurement of Tomato Leaf Area Using Computer Image Process...

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作者： An Dengkui Li Minzan Zhang Li Key Laboratory of Modern Precision Agriculture System Integration Research China Agricultural UniversityMinistry of Education

The change of plant shape,size and color of leaves,flower shape and fruit shape was inseparable from the nutrition state and environment *** research started from the study of color,shape and texture characters of crops,and tried to acquire plant growth information by abstracting the plant morphological characters,size and color of leaves,flower shape,fruit shape,*** digital image processing *** information would be an important reference factor when greenhouse control decision was being made.A software program was finished for crop information abstracting based on the current digital image processing *** program can be used to measure tomato leaf *** algorithm used to remove petiole combined erosion,dilation thinning algorithm and did less damage to tomato leaf image than simply use erosion and dilation algorithm.30 greenhouse tomato leaf samples were picked to examine the abstracting *** results of the image processing measurements and the measurements using portable area meter LI-3000 were analyzed and the correlation coefficient of single-leaf areas is 0.962,which shows that the algorithm is very *** characters that were abstracted in this research are not enough for analysis on the plant growth information,but the study laid a foundation for further research.

关键词： Image Processing Technology leaf area Tomato Petiole Removing Algorithm

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