Modeling the Growth of Eucalyptus Plants Based on the Thermal Sum

Oliveira, Aline Santana de; Ribeiro, Aristides; Silva, Carla Raphaela Araújo; Xavier, Aloísio; Freitas, Alex Ferreira de

doi:10.1590/1806-90882017000200012

Cited by 4 publications

(3 citation statements)

References 15 publications

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“…In the agronomic field, the modeling has been used to estimate the period of occurrence of phenological phases (LEE et al, 2003), in the identification of intrinsic characteristics of the physiology of each species, in the form in which each organ contributes to the final growth (BENINCASA, 2003), as well as to predict crop yield (GOMES et al, 2014). Furthermore, the modeling allows to study the growth processes, relating them to the number of days since the cultivation or plant emergence (AUGOSTINHO et al, 2008), or even relating them to the meteorological variables of the environment in which the plant is found (OLIVEIRA et al, 2017). However, for these models to be reliable, it is necessary that, when fitted, they describe the phenomenon as close as possible to reality (BRITO et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Gompertz and Logistic models for morphological traits of sudangrass cultivars during sowing seasons

Pezzini

Filho

et al. 2019

SCA

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The use of mathematical models in the study plant growth allows the identification of phases important to the cultivars and comparison between cultivars of the same species. The objectives of this work were to fit the Gompertz and Logistic growth models for the traits of plant height and stem length as a function of the accumulated thermal sum and accumulated solar radiation, to compare the fittings and the behavior of the sudangrass cultivars and indicate the model that best describes the growth of the cultivars during four sowing seasons. Were conducted eight uniformity trials with sudangrass. At 15 days after emergence, were began the collect and evaluation of five plants from each trial. Were measured plant height and stem length. The models were fitted using the values obtained for the traits of the five plants in each evaluation as a function of the accumulated thermal sum and accumulated solar radiation. Were estimated the parameters, determined their interval of confidence, critical points in the growth curves and quality indicators of the fit. The intrinsic nonlinearities and the parameter effect were also quantified. The accumulated thermal sum and accumulated solar radiation are adequate for the use as an independent variable in the model fitted. Both models were adequate to describe the growth of the traits plant height and stem length of cultivars BRS Estribo and CG Farrapo. However, the Logistic model is more accurate.A utilização de modelos matemáticos no estudo do crescimento de plantas possibilita a identificação de fases importantes para a cultura e a comparação entre cultivares de uma mesma espécie. Os objetivos deste trabalho foram ajustar modelos de crescimento, Gompertz e Logístico, para os caracteres altura de planta e comprimento de colmo em função da soma térmica acumulada e da radiação solar acumulada, comparar os ajustes e o comportamento das cultivares de capim-sudão e indicar o modelo que melhor descreve o crescimento das cultivares em quatro épocas de semeadura. Foram conduzidos oito ensaios Pezzini, R. V. et al. de uniformidade com capim-sudão. Aos 15 dias após a emergência, foi iniciada a coleta e avaliação de cinco plantas de cada ensaio. Foram mensurados a altura de planta e o comprimento de colmo. O ajuste dos modelos foi realizado com os valores dos caracteres das cinco plantas em cada avaliação, em função da soma térmica acumulada e da radiação solar acumulada. Foram estimados os parâmetros, determinado o intervalo de confiança dos parâmetros, os pontos críticos das curvas de crescimento e os indicadores de qualidade do ajuste. Também foram quantificadas as não linearidades intrínseca e do efeito do parâmetro. A soma térmica acumulada e a radiação solar acumulada são adequadas para serem utilizadas como variável independente no ajuste dos modelos. Para descrever o crescimento dos caracteres altura de planta e comprimento de colmo das cultivares BRS Estribo e CG Farrapo ambos os modelos são adequados. Entretanto, o modelo Logístico apresenta maior precisão. Palavras-chave: M...

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Section: Introductionmentioning

confidence: 99%

Gompertz and Logistic models for morphological traits of sudangrass cultivars during sowing seasons

Pezzini

Filho

et al. 2019

SCA

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“…It is possible to plan periods and types of management more appropriate for the crop using these models, aiming to reach higher yields (Pereira, Morais, Scalco, & Fernandes, 2014). In addition, the fit of models in function of meteorological variables makes it possible to understand the growth according to the environmental characteristics (Oliveira, Ribeiro, Silva, Xavier, & Freitas, 2017).…”

Section: Introductionmentioning

confidence: 99%

Modeling the Growth of Sudangrass Cultivars at Sowing Times

Pezzini¹,

Filho²,

Carini³

et al. 2019

JAS

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This study aimed to fit the Gompertz and Logistic growth models to evaluate the description of fresh and dry masses of shoot as a function of accumulated thermal sum and accumulated solar radiation, to compare the fittings, and to indicate which one best describes the growth of two sudangrass cultivars at four sowing times. Eight uniformity trials were conducted with the sudangrass crop. Five plants were collected from each trial for weighing of fresh and dry shoot masses. These evaluations were carried out three times a week starting from 15 days after plant emergence. The Gompertz and Logistic models were fitted to the masses as a function of accumulated thermal sum and accumulated solar radiation. The parameters and their confidence intervals were estimated. The points of maximum acceleration, inflection, maximum deceleration and asymptotic deceleration, and fit quality indicators were calculated. The intrinsic nonlinearity and the parameter-effects nonlinearity were quantified. The independent variables accumulated thermal sum and accumulated solar radiation can be used to fit the models. Both models satisfactorily describe the growth of fresh and dry shoot masses of cultivars BRS Estribo and CG Farrapo. The Logistic model is more accurate.

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“…Assim, foram calculadas as porcentagens de anos de El Niño, La Niña e Neutros, com valores de ICA PP , ICA PA e Q ICA acima, abaixo e dentro do intervalo IQR. 2007;ABREU et al, 2015;MARTINS;ABREU, 2017;OLIVEIRA et al, 2017) até o estágio mais avançado do ciclo MENDONÇA et al, 2017), afetando o déficit de pressão de vapor e, consequentemente, o mecanismo de abertura e fechamento dos estômatos, a absorção de CO 2 e a fotossíntese, a distribuição de fotoassimilados, a respiração de manutenção e, finalmente, a produção de biomassa oriunda da fotossíntese líquida (RIBEIRO et al, 2009;TAIZ;ZEIGER, 2013).…”

Section: Avaliação Do Crescimento Do Eucalipto Em Eventos De Enosunclassified

Adaptação do modelo da zona agroecológica para a estimação do crescimento e produtividade de eucalipto

Freitas¹

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Adaptation of the agroecological zone model to estimate eucalyptus growth and yield Among the forest species, the Eucalyptus is the most planted one in Brazil, with approximately 7.8 million hectares, having a huge economic importance for the country. Therefore, a better knowledge and quantification of the factors that affect forests growth and yield is of high important. Based on that, this study had as objectives: i) to adapt, calibrate and evaluate the Agroecological Zone Model (AEZ-FAO) to estimate growth and yield of eight eucalyptus clones in different Brazilian producing regions; ii) to identify the magnitude and major causes of yield gaps of eucalyptus in different producing regions of Minas Gerais state, Brazil; and iii) to identify the influence of El Niño, La Niña and Neutral events on eucalyptus yield in 12 Brazilian producing regions. The model´s coefficients, such as correction for the harvest index (Cc), water deficit sensitivity index (ky), leaf area index curve (LAI), root growth curve (Zr) and crop coefficient (kc), were calibrated. Penalization functions for considering the occurrence of frost events (f frost) and mortality by long periods of accumulated water deficit (f wd) were also included in the model. The calibration and adaptation of the model resulted in a significant improvement of its performance (accuracy and precision), for both calibration and evaluation phases. The RMSE was 110 m 3 ha-1 in the initial phase of calibration while in the final phase, RMSE was reduced to 39 m 3 ha-1 , the R² was increase from 0.73 to 0.82, and the agreement index (d) was also improved going from 0.70 to 0.93. In relation to the yield gaps, the water deficit was the main factor of yield reduction, corresponding to 77% of the total yield gap (YG T), while losses due to sub-optimum management corresponded to 23% of YG T. In order to evaluate the eucalyptus growth under different ENSO events, from 1983 to 2016, the Current Annual Increment (CAI) in the period of maximum growth, 3rd year of the cycle, was used. The eucalyptus yield and yield gap during the ENSO events were widely variable both spatially and temporally as a consequence of the different thermal and water regimes of the producing regions. It was not possible to identify a clear pattern thee relationship between ENSO and eucalyptus yield in the different Brazilian regions assessed.

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Modeling the Growth of Eucalyptus Plants Based on the Thermal Sum

Cited by 4 publications

References 15 publications

Gompertz and Logistic models for morphological traits of sudangrass cultivars during sowing seasons

Gompertz and Logistic models for morphological traits of sudangrass cultivars during sowing seasons

Modeling the Growth of Sudangrass Cultivars at Sowing Times

Adaptação do modelo da zona agroecológica para a estimação do crescimento e produtividade de eucalipto

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