scholarly journals Nonlinear models in the height description of the Rhino sunflower cultivar

2022 ◽  
Vol 52 (3) ◽  
Author(s):  
Anderson Chuquel Mello ◽  
Marcos Toebe ◽  
Rafael Rodrigues de Souza ◽  
João Antônio Paraginski ◽  
Junior Carvalho Somavilla ◽  
...  

ABSTRACT: Sunflower produces achenes and oil of good quality, besides serving for production of silage, forage and biodiesel. Growth modeling allows knowing the growth pattern of the crop and optimizing the management. The research characterized the growth of the Rhino sunflower cultivar using the Logistic and Gompertz models and to make considerations regarding management based on critical points. The data used come from three uniformity trials with the Rhino confectionery sunflower cultivar carried out in the experimental area of the Federal University of Santa Maria - Campus Frederico Westphalen in the 2019/2020 agricultural harvest. In the first, second and third trials 14, 12 and 10 weekly height evaluations were performed on 10 plants, respectively. The data were adjusted for the thermal time accumulated. The parameters were estimated by ordinary least square’s method using the Gauss-Newton algorithm. The fitting quality of the models to the data was measured by the adjusted coefficient of determination, Akaike information criterion, Bayesian information criterion, and through intrinsic and parametric nonlinearity. The inflection points (IP), maximum acceleration (MAP), maximum deceleration (MDP) and asymptotic deceleration (ADP) were determined. Statistical analyses were performed with Microsoft Office Excel® and R software. The models satisfactorily described the height growth curve of sunflower, providing parameters with practical interpretations. The Logistics model has the best fitting quality, being the most suitable for characterizing the growth curve. The estimated critical points provide important information for crop management. Weeds must be controlled until the MAP. Covered fertilizer applications must be carried out between the MAP and IP range. ADP is an indicator of maturity, after reaching this point, the plants can be harvested for the production of silage without loss of volume and quality.

2018 ◽  
Vol 10 (12) ◽  
pp. 157 ◽  
Author(s):  
Jéssica Andiara Kleinpaul ◽  
Alberto Cargnelutti Filho ◽  
Daniela Lixinski Silveira ◽  
Ismael Mario Marcio Neu ◽  
Cirineu Tolfo Bandeira ◽  
...  

Adjusting nonlinear Gompertz and Logistic models will help in the understanding of the growth pattern of the rye crop and also in the height response of the plant, when planted in different environmental conditions. The the aims of this study were to adjust the nonlinear Gompertz and Logistic models for plant height and indicate the one that best describes growth of two rye cultivars in five sowing times. Ten uniformity trials were conducted with the rye crop in the 2016 harvest. In each trial, ten randomly selected plants were evaluated from the first expanded leaf weekly. In each plant height was measured. The adjustment of the Gompertz and Logistic models as a function of the accumulated thermal sum was performed with the average plant height at each evaluation. The parameters a, b, and c were estimated for each model. The confidence interval for each parameter and the inflection points, maximum acceleration, maximum deceleration and asymptotic deceleration were calculated. The quality of fit of the models was verified by the coefficient of determination, Akaike's information criterion and residual standard deviation. Intrinsic non-linearity and non-linearity of the parameter effect were quantified. Both models describe satisfactorily the plant height. The model that best describes the growth of rye cultivars is Logistic.


Author(s):  
Jéssica A. Kleinpaul ◽  
Alberto Cargnelutti Filho ◽  
Fernanda Carini ◽  
Rafael V. Pezzini ◽  
Gabriela G. Chaves ◽  
...  

ABSTRACT This study aimed to adjust the Gompertz and Logistic nonlinear models for the fresh and dry matter of aerial part and indicate the model that best describes the growth of two rye cultivars in five sowing seasons, as well as to characterize the growth of the cultivars regarding the fresh and dry matter of aerial part. Ten uniformity trials were conducted with the rye crop in 2016. A weekly sampling and evaluation of 10 plants per trial was performed from the time the plants presented one expanded leaf. For each plant, the fresh and dry matter of aerial part were weighed. The Gompertz and Logistic models were adjusted to the accumulated thermal time based on the measures of each trait in each assessment. Also the parameters a, b, and c for each model were estimated and calculated the interval of confidence for each parameter, as well as the inflection points, maximum acceleration, maximum deceleration and asymptotic deceleration. The quality of the model adjustments was verified using the coefficient of determination, Akaike information criterion, and residual standard deviation. The intrinsic nonlinearity and nonlinearity of the parameter effect was quantified. Both models satisfactorily describe the behavior of the fresh and dry matter of aerial part. The Logistic model best describes the growth of rye cultivars. The growth of the cultivars BRS Progresso and Temprano is distinct between sowing seasons. Cultivar BRS Progresso requires a lower thermal time until reaching 50% of its growth when compared to the Temprano cultivar.


2017 ◽  
Vol 48 (1) ◽  
Author(s):  
Thais Destefani Ribeiro ◽  
Taciana Villela Savian ◽  
Tales Jesus Fernandes ◽  
Joel Augusto Muniz

ABSTRACT: The goal of this study was to elucidate the growth and development of the Asian pear fruit, on the grounds of length, diameter and fresh weight determined over time, using the non-linear Gompertz and Logistic models. The specifications of the models were assessed utilizing the R statistical software, via the least squares method and iterative Gauss-Newton process (DRAPER & SMITH, 2014). The residual standard deviation, adjusted coefficient of determination and the Akaike information criterion were used to compare the models. The residual correlations, observed in the data for length and diameter, were modeled using the second-order regression process to render the residuals independent. The logistic model was highly suitable in demonstrating the data, revealing the Asian pear fruit growth to be sigmoid in shape, showing remarkable development for three variables. It showed an average of up to 125 days for length and diameter and 140 days for fresh fruit weight, with values of 72mm length, 80mm diameter and 224g heavy fat.


2018 ◽  
Vol 39 (3) ◽  
pp. 1327
Author(s):  
Cleber Franklin Santos de Oliveira ◽  
João Marcos Novais Tavares ◽  
Gerusa Da Silva Salles Corrêa ◽  
Bruno Serpa Vieira ◽  
Silvana Alves Pedrozo Vitalino Barbosa ◽  
...  

The aim of this study was to compare mathematical models describing growth curves of white-egg layers at different population densities. To fit the models, 4,000 growing white-egg layers were utilized. The experimental design was completely randomized, with population densities of 71, 68, 65, 62, and 59 birds per cage in the starter phase and 19, 17, 15, 13, and 11 birds per cage in the grower phase, with 10 replicates each. Birds were weighed weekly to determine the average body weight and the weight gain. Gompertz and Logistic models were utilized to estimate their growth. The data analysis was carried out using the PROC NLMIXED procedure of the SAS® statistical computer software to estimate the parameters of the equation because mixed models were employed. The mean squared error, the coefficient of determination, and Akaike’s information criterion were used to evaluate the quality of fit of the models. The studied models converged for the description of the growth of the birds at the different densities studied, showing that they were appropriate for estimating the growth of white-egg layers housed at different population densities. The Gompertz model showed a better fit than the Logistic model.


2018 ◽  
pp. 7104-7107
Author(s):  
Aureliano Juárez-Caratachea ◽  
Iván Delgado-Hurtado ◽  
Ernestina Gutiérrez-Vázquez ◽  
Guillermo Salas-Razo ◽  
Ruy Ortiz-Rodríguez ◽  
...  

Objective. Determine the best non-linear model to fit the growth curve of local turkeys managed under confinement in Michoacan, Mexico. Material and methods. Twenty-four and 43 female and male turkeys, reared under commercial conditions were given commercial feed. Birds were weighed weekly from hatch to 29 weeks of age. The Gompertz, Brody, Richards, von Bertalanffy and Logistic models were chosen to describe the age-weight relationship. Results. The best fitting model was selected based on the multiple determination coefficient (R2), the Akaike information criterion (AIC) and visual analysis of the observed and predicted curves. In both female and male, von Bertalanffy was the best model. The highest estimates of parameter A (mature weight) for both females and males were obtained with the von Bertalanffy model followed by the Gompertz and Logistic. The estimates of A were higher for males than for females. The highest estimates of parameter k (rate of maturity) for both females and males were, in decreasing order, for the Logistic, Gompertz, and von Bertalanffy models. k values for female turkeys was higher than for males. The age at the point of inflection (TI) and body weight at the age of point of inflection (WI) varied with the model used. The largest values of TI and WI corresponded to the Logistic model. Between sexes, the largest TI and WI values corresponded to males. Conclusions. The best models to describe turkey growth was the von Bertalanffy because it present the highest R2 and lowest AIC values.


2019 ◽  
Vol 49 (2) ◽  
pp. 81-90 ◽  
Author(s):  
Reinaldo Imbrozio BARBOSA ◽  
Perla Natalia RAMÍREZ-NARVÁEZ ◽  
Philip Martin FEARNSIDE ◽  
Carlos Darwin Angulo VILLACORTA ◽  
Lidiany Camila da Silva CARVALHO

ABSTRACT Allometric models defining the relationship between stem diameter and total tree height in the Amazon basin are important because they refine the estimates of tree carbon stocks and flow in the region. This study tests different allometric models to estimate the total tree height from the stem diameter in an ecotone zone between ombrophilous and seasonal forests in the Brazilian state of Roraima, in northern Amazonia. Stem diameter and total height were measured directly in 65 recently fallen trees (live or dead). Linear and nonlinear regressions were tested to represent the D:H relation in this specific ecotone zone. Criteria for model selection were the standard error of the estimate (Syx) and the adjusted coefficient of determination (R²adj), complemented by the Akaike Information Criterion (AIC). Analysis of residuals of the most parsimonious nonlinear models showed a tendency to overestimate the total tree height for trees in the 20-40 cm diameter range. Application of our best fitted model (Michaelis-Menten) indicated that previously published general equations for the tropics that use diameter as the independent variable can either overestimate tree height in the study area by 10-29% (Weibull models) or underestimate it by 8% (climate-based models). We concluded that our site-specific model can be used in the ecotone forests studied in Roraima because it realistically reflects the local biometric relationships between stem diameter and total tree height. Studies need to be expanded in peripheral areas of northern Amazonia in order to reduce uncertainties in biomass and carbon estimates that use the tree height as a variable in general models.


2020 ◽  
Vol 66 (No. 9) ◽  
pp. 375-382
Author(s):  
Aleksandr Lebedev

The accuracy of determining the height of trees is essential both in forestry and in scientific research. Height is usually determined using specific models, where it is a function of the diameter at breast height. On the materials of 23 sample plots with the measurement of model trees in birch stands, the parameters were determined for 29 two-parameter and three-parameter models that are most often found in literary sources. The following metrics evaluated the quality of the models: root mean square error, mean absolute percentage error, coefficient of determination, adjusted coefficient of determination, Akaike information criterion, and Bayesian information criterion. Three-parameter models of the dependence of height on diameter by a set of metrics show somewhat better quality than two-parameter models. Nevertheless, in general, the differences between most models are minor. Along with the models selected as the best, the Näslund and Chapman-Richards equations, which are often used in the literature as the most flexible, showed good quality. The methodology of this study allows you to repeat the same work for tree species and forest conditions, for which information on the nature of the relationship of height with diameter is incomplete or missing.


2017 ◽  
Vol 38 (3) ◽  
pp. 1265
Author(s):  
Josiane Pasini ◽  
Lucimara Rogéria Antoniolli ◽  
Renar João Bender

Pears have a very sensitive epidermis and are prone to signal mechanical blemishes, which result in reduced visual quality and low consumer acceptance. The objective of this work was to identify critical points and the magnitude of impact forces on a packing line at a commercial packinghouse. The effect of injuries on ripening and quality of ´Packham´s Triumph´ pears was also evaluated after cold storage. The packing line was scrutinized on its transfer points, fruit drop heights and cushioning overlays, which allowed to acquire the maximum accelerations on each spot. The maximum acceleration forces were reproduced in the lab with ‘Packham’s Triumph’ pears to evaluate the effects on fruit quality after cold storage. Four critical points were noticed on the packing line: at the transfer from the conveyor belt to the lifting rollers, at the transfer from the lifting rollers to the washing ramp with rotatory brushes, at the entrance to the singulator at the end of the conveyor belt and at the drop from the sizer to the packing stalls. Ripening of ‘Packham’s Triumph’ pears invariably came about during cold storage, and independently of the imposed impacts. The impacts under the circumstances of the test did not affect the quality of ´Packham´s Triumph´ pears kept for up to 120 days at cold storage followed by five days at room temperature.


2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Edilson Marcelino Silva ◽  
Ariana Campos Fruhauf ◽  
Sérgio Alberto Jane ◽  
Édipo Menezes da Silva ◽  
Joel Augusto Muniz ◽  
...  

Litter is an important source of nutrients for trees and can improve the quality of degraded soils. The objective of this study was to describe the dynamics of carbon mineralization in litter soils using nonlinear models, estimating half-life times. Soil carbon mineralization under three types of forest cover was evaluated: Atlantic forest fragment (capoeira), Acacia auriculiformis trees (acacia), and Mimosa caesalpiniifolia (sabiá) from a reforested area with a history of degradation. Twelve measurements of the mineralized carbon were made up to 222 days after the beginning of the incubation of litter soils. Stanford and Smith, Juma, and Cabrera models were fitted by the least squares method using the Gauss-Newton algorithm in the R software. The Stanford and Smith model was more appropriate in describing all treatments, based on the Akaike Information Criterion, with estimates of half-life for Acácia, Capoeira, and Sabiá soils at 25, 44, and 51 days, respectively. The Stanford and Smith and Juma nonlinear models satisfactorily described the carbon mineralization of soils of all treatments.


Author(s):  
А.В. Лебедев ◽  
В.В. Кузьмичев

Важное значение как в лесохозяйственных работах, так и при проведении научных исследований имеет точность определения высоты деревьев. Высота обычно определяется с использованием конкретных моделей, где она является функцией от диаметра дерева на высоте груди. Наиболее простыми моделями зависимости высоты деревьев от диаметра на высоте груди являются двухпараметрические, и они находят широкое применение в лесотаксационных работах. На материалах 23 пробных площадей с измерением модельных деревьев, заложенных в березовых древостоях Лесной опытной дачи Тимирязевской сельскохозяйственной академии, проводилось определение параметров для 14 двухпараметрических моделей, наиболее часто встречающихся в литературных источниках. Параметры моделей вычислялись путем минимизации среднеквадратической ошибки. Качество моделей оценивалось по следующим метрикам: квадратный корень из среднеквадратической ошибки, коэффициент детерминации, информационный критерий Акаике, информационный критерий Байеса. Полученные результаты подтвердили целесообразность использования на практике ряда уравнений, которые среди двухпараметрических моделей показывают приемлемое качество. Результаты анализа данных показывают, что со статистической точки зрения полученные различия в качестве моделей не являются значимыми на 5-м уровне (t-тест). Обоснованные в качестве лучших модели зависимости высоты от диаметра на высоте груди могут быть использованы на практике при выполнении лесохозяйственных и научно-исследовательских работ в березовых древостоях, произрастающих в центральных регионах европейской части России. Методика проведенного исследования позволяет повторить аналогичную работу для древесных пород и лесорастительных условий, для которых информация о характере связи высоты с таксационным диаметром является неполной или отсутствует. The accuracy of determining the height of trees is important both in forestry and in scientific research. Height is usually determined using specific models, where it is a function of the diameter at breast height. The simplest models of the dependence of tree height on diameter at breast height are two-parameter, and they are widely used in forest taxation researches. On the materials of 23 sample plots with the measurement of model trees laid in birch stands of the Forest Experimental District of the Timiryazev Agricultural Academy, the parameters were determined for the 14 bi-parameter models that are most often found in literary sources. Model parameters were calculated by minimizing the standard error. The quality of the models was evaluated by the following metrics: the square root of the standard error, the coefficient of determination, the Akaike information criterion, the Bayes information criterion. The obtained results confirmed the feasibility of using in practice several equations, which among the biparameter models show acceptable quality. The results of data analysis show that, from a statistical point of view, the differences obtained in the quality of models are not significant at the 5 level (t-test). Substantiated as the best models of the dependence of height on diameter at breast height can be used in practice when performing forestry and research work in birch stands growing in the central regions of the European part of Russia. The methodology of the study allows you to repeat the same work for tree species and forest conditions, for which information about the nature of the relationship of height with the diameter at breast height is incomplete or absent.


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