scholarly journals ÁREA DO LIMBO FOLIAR DA CASTANHEIRA-DO-BRASIL POR MEDIDAS LINEARES

Nativa ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 380-388
Author(s):  
Luana Bouvié ◽  
Andréa Carvalho da Silva ◽  
Daniela Roberta Borella ◽  
Cátia Cardoso da Silva ◽  
Mariana Pizzatto
Keyword(s):  
Leaf Area ◽  
Leaf Blade ◽  
Leaf Length ◽  
Mean Square ◽  
Brazil Nut ◽  
Linear Measurements ◽  
Statistical Validation ◽  
Bertholletia Excelsa ◽  
The Mean ◽  
Statistical Performance Evaluation

Neste trabalho foram gerados e validados modelos de estimativa da área da folha da espécie Bertholletia excelsa Bonpl. (castanheira-do-Brasil) a partir das medidas lineares do limbo foliar. Foram coletadas 1500 folhas em diferentes posições da copa de árvores adultas e jovens (em função do ciclo reprodutivo), sendo usadas 1000 e 500 folhas para calibração e validação estatísticas, respectivamente. Foram obtidos como medidas do limbo da folha: comprimento (C), largura (no centro da folha, na base e no ápice) e a área foliar real (AFR). A avaliação do desempenho estatístico (validação) foi realizada pelos indicativos erro médio (MBE), raiz quadrática do erro médio (RMSE) e índice de ajustamento de Willmott (dW). Apenas a medida de largura no centro da folha e do comprimento são suficientes para estimar a área da folha de B. excelsa., que pode ser dada pela equação AF = {0,8743*{(C*L)0,9790]}-1,84, independentemente da posição da folha e da idade planta. Palavras-chave: Bertholletia excelsa; análise de regressão; indicativos estatísticos. FIELD OF THE LIMBO FOLIAR OF CASTANHEIRA-DO-BRASIL WITH LINEAR MEASURES  ABSTRACT: In this work, models of estimation of the leaf area of the species Bertholletia excelsa Bonpl. (Brazil nut) from the linear measurements of the leaf blade. 1500 leaves were collected in different positions of the crown of adult and young trees (depending on the reproductive cycle), using 1000 and 500 leaves for calibration and statistical validation, respectively. Leaf length (C), width (at the center of the leaf, at the base and at the apex) and leaf area (AFR) were obtained as measures of leaf limb. Statistical performance evaluation (validation) was performed using the mean error (MBE), root mean square error (RMSE) and Willmott's index of adjustment (dW). Only the width measure at the center of the leaf and the length are sufficient to estimate the area of the leaf of B. excelsa., Which can be given by the equation AF = {0.8743 * {(C * L) 0.9790]} -1.84, regardless of leaf position and plant age.Keywords: Bertholletia excelsa; regression analysis; statistical indicatives.

scholarly journals Estimation of leaf area for greenhouse cucumber by linear measurements under salinity and grafting

2005 ◽  
Vol 62 (4) ◽  
pp. 305-309 ◽  
Author(s):  
Flávio Favaro Blanco ◽  
Marcos Vinícius Folegatti
Keyword(s):  
Leaf Area ◽  
Direct Measurement ◽  
Leaf Length ◽  
The Other ◽  
Salinity Level ◽  
Linear Measurements ◽  
Cucumber Seedlings ◽  
Growing Period ◽  
Greenhouse Cucumber

The measurement of leaf area by linear parameters is a useful tool when plants cannot be destroyed for direct measurement. The objectives of this study were to establish equations to estimate the leaf area of greenhouse-cucumber and to evaluate the effects of salinity and grafting on this estimative. Non-grafted cucumber seedlings, cv. 'Hokushin', were transplanted in a greenhouse and were irrigated with water of different salinities (1.0, 3.2 and 5.0 dS m-1). In the second growing period, the same cultivar was grafted on Cucurbita spp. and the plants were irrigated with water of 1.4, 3.0 and 5.3 dS m-1. Leaves of different sizes were collected from both experiments and leaf area was determined by an integrating area meter. Leaf length (L) and width (W) were also recorded. An equation for estimating the leaf area from L and W was developed for a given salinity level or grafting condition and estimated well the area of leaves collected in the other treatments. The leaf area (LA) of cucumber 'Hokushin' could be estimated using the equation LA = 0.88LW - 4.27, for any grafting and salinity conditions.

scholarly journals Evaluation and reparametrization of mathematical models for prediction of the leaf area of Megathyrsus maximus cv. BRS Zuri

2020 ◽  
Vol 8 (3) ◽  
pp. 214-219
Author(s):  
Patrick Bezerra Fernandes ◽  
Rodrigo Amorim Barbosa ◽  
Maria Da Graça Morais ◽  
Cauby De Medeiros-Neto ◽  
Antonio Leandro Chaves Gurgel ◽  
...  
Keyword(s):  
Regression Model ◽  
Leaf Area ◽  
Multiple Regression ◽  
Leaf Blade ◽  
Multiple Regression Model ◽  
Leaf Length ◽  
Predictor Variables ◽  
Mato Grosso ◽  
Linear Multiple Regression ◽  
Model C

The aim of this study was to verify the precision and accuracy of 5 models for leaf area prediction using length and width of leaf blades of Megathyrsus maximus cv. BRS Zuri and to reparametrize models. Data for the predictor variables, length (L) and width (W) of leaf blades of BRS Zuri grass tillers, were collected in May 2018 in the experimental area of Embrapa Gado de Corte, Mato Grosso do Sul, Brazil. The predictor variables had high correlation values (P<0.001). In the analysis of adequacy of the models, the first-degree models that use leaf blade length (Model A), leaf width × leaf length (Model B) and linear multiple regression (Model C) promoted estimated values similar to the leaf area values observed (P>0.05), with high values for determination coefficient (>80%) and correlation concordance coefficient (>90%). Among the 5 models evaluated, the linear multiple regression (Model C: β0 = -5.97, β1 = 0.489, β2 = 1.11 and β3 = 0.351; R² = 89.64; P<0.001) and as predictor variables, width, length and length × width of the leaf blade, are the most adequate to generate precise and exact estimates of the leaf area of BRS Zuri grass.

scholarly journals Modelling of the leaf area for various pear cultivars using neuro computing approaches

2020 ◽  
Vol 17 (4) ◽  
pp. e0206
Author(s):  
Ahmet Öztürk ◽  
Bilal Cemek ◽  
Hüsnü Demirsoy ◽  
Erdem Küçüktopcu
Keyword(s):  
Linear Regression ◽  
Leaf Area ◽  
Important Variable ◽  
Leaf Length ◽  
Yield Potential ◽  
Plant Growth And Development ◽  
Estimation Model ◽  
Linear Measurements ◽  
Nutrient Use ◽  
Ann Models

Aim of study: Leaf area (LA) is an important variable for many stages of plant growth and development such as light interception, water and nutrient use, photosynthetic efficiency, respiration, and yield potential. This study aimed to determine the easiest, most accurate and most reliable LA estimation model for the pear using linear measurements of leaf geometry and comparing their performance with artificial neural networks (ANN).Area of study: Samsun, Turkey. Material and methods: Different numbers of leaves were collected from 12 pear cultivars to measure leaf length (L), and width (W) as well as LA. The multiple linear regression (MLR) was used to predict the LA by using L and W. Different ANN models comprising different number of neuron were trained and used to predict LA.Main results: The general linear regression LA estimation model was found to be LA = -0.433 + 0.715LW (R2 = 0.987). In each pear cultivar, ANN models were found to be more accurate in terms of both the training and testing phase than MLR models.Research highlights: In the prediction of LA for different pear cultivars, ANN can thus be used in addition to MLR, as effective tools to circumvent difficulties met in the direct measurement of LA in the laboratory.

scholarly journals MODELOS ALOMÉTRICOS PARA ESTIMAR A ÁREA DO LIMBO FOLIAR DE TECA

Nativa ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 129
Author(s):  
Cátia Cardoso da Silva ◽  
Adilson Pacheco Souza ◽  
Luana Bouvié ◽  
Brena Geliane Ferneda ◽  
Adelson Leite Neto ◽  
...  
Keyword(s):  
Leaf Area ◽  
Tectona Grandis ◽  
Dry Mass ◽  
Statistical Validation ◽  
Mean Error ◽  
Adult Trees ◽  
Middle Leaf ◽  
Blade Area ◽  
Statistical Performance Evaluation ◽  
Weighted Values

Objetivou-se neste trabalho gerar e validar 16 modelos simplificados para estimar a área do limbo foliar de árvores de Tectona grandis L. Foram coletadas folhas de árvores adultas em plantios homogêneos e em matrizes isoladas, nos estratos superior, médio e basal das copas, totalizando 1800 folhas. A área foliar real foi determinada usando o integrador de área foliar “Area Meter” (LI-3100C). Nos modelos de estimativa, considerou-se a área foliar como variável dependente, massa seca (MS) e as dimensões lineares da folha (comprimento – C e largura do meio da folha - L) como variáveis independentes. Para calibração e validação estatística, utilizou-se 70% e 30% das folhas, nesta ordem. Na avaliação do desempenho estatístico (validação) empregou-se o erro médio (MBE), raiz quadrática do erro médio (RMSE) e índice de ajustamento de Wilmott (dw). Empregou-se o método dos valores ponderados dos indicativos estatísticos (Vp) para definir qual a melhor modelo. Os modelos que empregam medidas conjuntas de C e L proporcionam melhores estimativas da área do limbo foliar de T. grandis, sendo indicado o modelo AF = 0,5776 C*L, que apresenta superestimava de 13,98 cm², espalhamento de 61,99 cm² e ajustamento de 0,99. Considerando a massa seca, recomenda-se o modelo AF = 91,9164 MS.Palavras-chave: Tectona grandis L.; indicativos estatísticos; morfometria foliar. ALLOMETRIC EQUATIONS FOR LEAF BLADE AREA ESTIMATION OF TEAK ABSTRACT: The objective of this work was to generate and validate 16 simplified models to estimate the leaf limb area of Tectona grandis L. trees. Leaves of adult trees were collected at homogeneous plantations and isolated matrices, in the upper, middle and basal strata of the crowns totalizing 1800 sheets. The actual leaf area was determined using the “Area Meter” leaf area integrator (LI-3100C). In the estimation models, the leaf area was considered as a dependent variable, dry mass and leaf linear dimensions (length - C and width of the middle leaf - L) as independent variables. For calibration and statistical validation, 70% and 30% of the leaves were used in this order. In the statistical performance evaluation (validation) we used the mean error (MBE), quadratic root mean error (RMSE) and Wilmott adjustment index (dw). We used the method of weighted values of statistical codes (Vp) to define the best model. Models employing C and L joint measurements provide better estimates of T. grandis leaf limb area, with the AF = 0.5776 C * L model being overestimated 13.98 cm², scattering 61.99. cm² and adjustment of 0.99. Considering the dry mass, the model AF = 91.9164 MS is recommended.Keywords: Tectona grandis L.; statistics indicatives; leaf morphometry.

scholarly journals 250 Using Leaf Area Devices (LADS) to Estimate Total Leaf Area of Coffee Plants

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 485C-485
Author(s):  
Guofan Liu ◽  
Kent D. Kobayashi
Keyword(s):  
Leaf Area ◽  
Leaf Length ◽  
Total Leaf Area ◽  
Estimation Errors ◽  
Total Leaf ◽  
Length Width ◽  
Leaf Density ◽  
Number Of Leaves ◽  
Coffee Plants ◽  
The Mean

It is difficult to estimate the total leaf area of coffee plants with accuracy due to the large number of leaves and the high leaf density of the plant canopy. In 1996, on Maui, Hawaii, 98 leaves of various sizes were randomly collected for each of five cultivars of Coffea arabica L. The cultivars used were `Guadalupe', `Guatemalan', `Mokka', `Red Catuai', and `Yellow Caturra'. Leaf length, width, and area were measured. Seventy-five leaves were used to develop leaf area models, and the remaining leaves were used to test the accuracy of the models using a 1:1 line. We then developed leaf area devices (LADs), which were made of sheet plastic and shaped to resemble coffee leaves. There were three groups of areas in the leaf area devices, based on leaf sizes. Total leaf area (TLA) contained three components. Each component related to the mean leaf area (k) and the number of leaves (n) in that group. The model for the total leaf area was: TLA = k1n1 + k2n2 + k3n3, where k is a constant in each group. The estimation errors for the different cultivars ranged from 5.6% to 12.3% for 1-year-old plants (four cultivars) and from 1.9% to 7.8% for mature plants (five cultivars). By using the LADs and counting the number of leaves, we can obtain the total leaf area for coffee plants in the field.

OCCURRENCE, DAMAGE PATTERN AND STATUS OF THE RICE LEAF FOLDER CNAPHALOCROCIS RURALIS WALKER (LEPIDOPTERA: CRAMBIDAE) IN ERIANTHUS SPP. IN INDIA

2018 ◽  
Vol 55 (3) ◽  
pp. 471-483 ◽  
Author(s):  
P. MAHESH ◽  
J. SRIKANTH ◽  
K. CHANDRAN ◽  
B. SINGARAVELU ◽  
K. P. SALIN ◽  
...  
Keyword(s):  
Leaf Area ◽  
Leaf Blade ◽  
Germplasm Collection ◽  
Leaf Length ◽  
Infestation Rate ◽  
Rice Leaf Folder ◽  
The World ◽  
Sugarcane Breeding Institute ◽  
First Occurrence ◽  
Kerala State

SUMMARYWe investigated the occurrence and status of the leaf folder Cnaphalocrocis ruralis (Walker) (Lepidoptera: Crambidae) in accessions of Erianthus spp. maintained as a part of the world germplasm collection at the Research Center of ICAR-Sugarcane Breeding Institute, Kannur, Kerala State, India. The nature, pattern, extent and year-to-year variation in damage were examined and accessions categorized based on relative incidence. The larvae of C. ruralis caused characteristic injury by feeding on chlorophyll bearing tissues leading to the formation of white and transparent streaks on the leaf blade. The grown-up larvae folded the leaf longitudinally with the adaxial surface inside the fold and exposing the abaxial surface, the edges being held in place by bands of silk thread at regular intervals. The length of leaf folds varied from 2.6 to 27.0 cm with a mean of 9.1 cm, which roughly constituted 7.3% of the mean length of the leaf blade. Leaf length, leaf width and leaf area were not correlated with either the leaf fold length or the number of webs. However, the leaf fold length was positively correlated with the number of webs. Attack rates (infestation rate) on cane basis (up to 69.0%) were generally higher than the damage rates (intensity) on leaf basis (up to 50.0%); infestation index ranged between 0.0 and 13.7%. Correlations between infestation rate and intensity varied among the three study years. Non-parametric analysis indicated significant differences among the three years for percent of infested canes and infestation index but not percent of damaged leaves. All accessions showed C. ruralis incidence in at least one experimental year, indicating that none of the accessions tested was immune to its attack. When all 74 accessions were considered on the basis of infestation index, 85.1% were placed in low and moderate categories and only 14.9% in high incidence category. Within the accessions of Erianthus spp., leaf area was not related to infestation rate of cane or damage rate of leaves but positively related to infestation index. The dynamics of the leaf folder in the predominantly paddy ecosystem were discussed in the light of its first occurrence in Erianthus spp. accessions in India and the world.

scholarly journals Brazil Nut (Bertholletia excelsa, Lecythidaceae) Regeneration in Logging Gaps in the Peruvian Amazon

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Julian Moll-Rocek ◽  
Matthew E. Gilbert ◽  
Eben N. Broadbent
Keyword(s):  
Leaf Area ◽  
Canopy Openness ◽  
Multiple Use ◽  
Brazil Nut ◽  
Total Leaf Area ◽  
Economic Resource ◽  
Bertholletia Excelsa ◽  
Brazil Nuts ◽  
Madre De Dios ◽  
Total Leaf

Brazil nut (Bertholletia excelsaBonpl.) extraction serves as an important economic resource in the Madre de Dios region of Peru simultaneously promoting forest conservation, yet, under current management, it cannot compete with other land uses. This study investigated the effects of logging gaps on Brazil nut natural regeneration. A total of 48 paired logging gap-understory sites were visited in Brazil nut concessions in the Tambopata province of Madre de Dios, Peru. At each site, the number of Brazil nut recruits was counted and canopy openness and gap area were measured. Significantly higher levels of recruit density were found in logging gaps than in understory sites. Additionally, recruit density was positively correlated with canopy openness. Further, in experimental plantings in paired gap and understory sites, canopy openness, height, total leaf area, and number were recorded from August 2011 to February 2012. Height, total leaf area, and leaf number were significantly higher for tree-fall gap grown seedlings, lending further evidence to improved recruitment success of Brazil nuts in forest gaps. These results suggest that multiple-use forest management could be considered as an alternative for the sustainable extraction of Brazil nuts but also highlight that further studies are required.

The Bordeaux Automatic Meridian Circle

1978 ◽  
Vol 48 ◽  
pp. 227-228
Author(s):  
Y. Requième
Keyword(s):  
Mean Square Error ◽  
Mean Square ◽  
Meridian Circle ◽  
The Mean ◽  
Full Automation

In spite of important delays in the initial planning, the full automation of the Bordeaux meridian circle is progressing well and will be ready for regular observations by the middle of the next year. It is expected that the mean square error for one observation will be about ±0.”10 in the two coordinates for declinations up to 87°.

The mean-square generalized delayed decision feedback sequence detector

2003 ◽  
Vol 14 (3) ◽  
pp. 265-268 ◽  
Author(s):  
Maurizio Magarini ◽  
Arnaldo Spalvieri ◽  
Guido Tartara
Keyword(s):  
Decision Feedback ◽  
Mean Square ◽  
The Mean

Limit tolerances for sums of measurement errors

2018 ◽  
Vol 934 (4) ◽  
pp. 59-62
Author(s):  
V.I. Salnikov
Keyword(s):  
Normal Distribution ◽  
Mean Square Error ◽  
Gaussian Distribution ◽  
Measurement Errors ◽  
Theory And Practice ◽  
Mean Square ◽  
The Mean ◽  
Limiting Values ◽  
Limiting Value

The question of calculating the limiting values of residuals in geodesic constructions is considered in the case when the limiting value for measurement errors is assumed equal to 3m, ie ∆рred = 3m, where m is the mean square error of the measurement. Larger errors are rejected. At present, the limiting value for the residual is calculated by the formula 3m√n, where n is the number of measurements. The article draws attention to two contradictions between theory and practice arising from the use of this formula. First, the formula is derived from the classical law of the normal Gaussian distribution, and it is applied to the truncated law of the normal distribution. And, secondly, as shown in [1], when ∆рred = 2m, the sums of errors naturally take the value equal to ?pred, after which the number of errors in the sum starts anew. This article establishes its validity for ∆рred = 3m. A table of comparative values of the tolerances valid and recommended for more stringent ones is given. The article gives a graph of applied and recommended tolerances for ∆рred = 3m.

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