Data/hora: 10/06/2024 18:16:59

Provedor de dados: | 63
País: | Brazil
Título: | Critical points in logistic growth curves and treatment comparisons
Autores: | Passos,José Raimundo de Souza; Pinho,Sheila Zambello de; Carvalho,Lídia Raquel de; Mischan,Martha Maria.
Data: | 2012-10-01
Ano: | 2012
Palavras-chave: | Nonlinear regression; Asymptotic regression; Stopping critical level; Seeds imbibition.
Resumo: | Several biological phenomena have a behavior over time mathematically characterized by a strong increasing function in the early stages of development, then by a less pronounced growth, sometimes showing stability. The separation between these phases is very important to the researcher, since the maintenance of a less productive phase results in uneconomical activity. In this report we present methods of determining critical points in logistic functions that separate the early stages of growth from the asymptotic phase, with the aim of establishing a stopping critical point in the growth and on this basis determine differences in treatments. The logistic growth model is fitted to experimental data of imbibition of araribá seeds (Centrolobium tomentosum). To determine stopping critical points the following methods were used: i) accelerating growth function, ii) tangent at the inflection point, iii) segmented regression; iv) modified segmented regression; v) non-significant difference; and vi) non-significant difference by simulation. The analysis of variance of the abscissas and ordinates of the breakpoints was performed with the objective of comparing treatments and methods used to determine the critical points. The methods of segmented regression and of the tangent at the inflection point lead to early stopping points, in comparison with other methods, with proportions ordinate/asymptote lower than 0.90. The non-significant difference method by simulation had higher values of abscissas for stopping point, with an average proportion ordinate/asymptote equal to 0.986. An intermediate proportion of 0.908 was observed for the acceleration function method.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162012000500004
Editor: | São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Relação: | 10.1590/S0103-90162012000500004
Formato: | text/html
Fonte: | Scientia Agricola  v.69 n.5 2012
Fonte: | info:eu-repo/semantics/openAccess