Precisão e controle de qualidade em experimentos de avaliação de cultivares
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Data
2007-09
Título da Revista
ISSN da Revista
Título de Volume
Editor
João Batista Duarte
Resumo
This study had as objective to propose a new approach
for quality evaluation of variety trials for determination of
cropping and use values (VCU), which considers three attributes
simultaneously: magnitude of the residual variation, replication
number, and genetic control of the trait under selection. It was
also emphasized the need for using shrinkage estimators/predictors
of genotypic values instead of unshrunk phenotypic means of
varieties, i.e., the procedures should consider the genetic
coefficient of determination of the traits, as well as the eventual
heterogeneity of residual variance within varieties. Targeting an
accuracy of 90%, it was concluded that Snedecor F test values
associated to treatment effects in the analysis of variance should
be above 5.0. The magnitude of genotypic variability of the traits
is also involved in the F statistics. This means that the approach
of fixing minimum values for replication number and maximum
values for residual variation coefficient (CVe) is not sufficient.
For traits related to yield (with low genetic coefficient of
determination) the normally used replication number, between
two and four, does not permit to reach the targeted accuracy,
even if residual variation coefficients below 10% are aimed, and
the experimentation is conducted on several sites and years. For
that target accuracy it is recommended the use of at least six
replications. It was also shown that shrinkage estimators provide
more precise and reliable inferences concerning genotypic means
of the varieties, and their use is encouraged.
Descrição
Palavras-chave
Acurácia, Estimador shrinkage, Heterogeneidade de variâncias, Estimador viciado, Coeficiente de variação, Accuracy, Shrinkage estimator, Variance heterogeneity, Biased estimator, variation coefficent
Citação
RESENDE, Marcos Deon Vilela de; DUARTE, João Batista. Precisão e controle de qualidade em experimentos de avaliação de cultivares. Pesquisa Agropecuária Tropical, Goiânia, v. 37, n. 3, p. 194-177, jul./set. 2007. Disponível em: <https://www.revistas.ufg.br/pat/article/view/1867/1773>.