Statistical selection for estimating the accuracy in experimental corn trials.
DOI:
https://doi.org/10.15517/am.v26i1.16920Keywords:
repeatability, coefficient of variation, mean square error, standard error of differenceAbstract
The objective of this study was to select the most optimal statistic to estimate the experimental accuracy and to assess the Coefficient of Variation often used to estimate the validity of experiments. For the analysis, 406 trials were included; from research conducted at El Ejido Experimental Station and at cornfields of contributing producers of Azuero Region, Panama, during 2000-2013. To each trial it was calculated the various components of variance or Mean Square (MS), Coefficient of Variation (CV), Repeatability, Rank, Least Significant Differences (LSD), Standard Error (SE), Coefficient of determination (R2) of treatment and residual. We found that the CV is more related than repeatability with the overall mean of the experiment (correlation index of 0.57 vs. 0.24), thus being less robust to indicate experimental accuracy. Increasing the number of repetitions of experiments with the same MS Error reduced the SE and increased accuracy. The repeatability of the experiment was highly related to both treatments R2 (0.93) and the unexplained fraction model (0.87), in contrast with the CV (0.23 and 0.23, respectively). When repeatability and CV were linked to the DMS/Range ratio, it was found that repeatability is highly correlated (R2 = 0.76) with this ratio, while the CV provided an R2 of 0.18. This result suggests that the repeatability is a better indicator than the CV for good experimental accuracy.Downloads
References
Barreto, H., y W.R. Raun. 1990. La precisión experimental de los ensayos regionales con maíz (Zea mays) a través de Centroamérica. En: T.J. Smyth, W.R. Raun y F. Bertsch, editores, Segundo Taller Latinoamericano de manejo de suelos tropicales, San José, Costa Rica 9-13 julio. Soil Science Department, North Carolina State University, NC, USA. p. 99-105.
Bowman, D.T., y J.O. Rawlings. 1995. Establishing a rejection procedure for crop performance data. Agron. J. 87:147-151.
Bowman, D.T., y C.E. Watson. 1997. Measures of validity in cultivar performance trials. Agron. J. 89:860-866.
Bowman, D.T. 2001. Common use of the CV: a statistical aberration in crop performance trials (Contemporary Issue). J. Cotton Sci. 5:137-141.
Gauch, H.G., y R.W. Zobel. 1996. Optimal replication in selection experiments. Crop Sci. 36:838-843.
Gómez, K.A., y A.A. Gómez 1984. Statistical procedures for agricultural research. 2nd ed. John Wiley Inter Science, Hoboken, NJ, USA.
Martínez, A. 1988. Diseños experimentales: métodos y elementos de teoría. Editorial Trillas, México.
Martínez, E. 2005. Errores frecuentes en la interpretación del coeficiente de determinación lineal. Anuario Jurídico y Económico Escurialense 38:315-332.
Patel, J.K., N.M. Patel, y R.L. Shiyani. 2001. Coefficient of variation in field experiments and yardstick thereof-an empirical study. Curr. Sci. 81(9):1163-1164.
Pimentel, F. 1985. Curso de estatística experimental. Livraria Nobel S.A., São Paulo, Brasil.
Ruíz-Ramírez, J. 2010. Eficiencia relativa y calidad de los experimentos de fertilización en el cultivo de caña de azúcar. Terra Latinoamericana 28:149-154.
Ruíz, D., y A.M. Sánchez. 2006. Apuntes de estadística. www.eumed.net/libros-gratis/2006a/rmss/index.htm (Consultado 7 jul. 2014).
Silveira Jr., P., J.B. Da Silva, A. Almeida, y E.P. Zonta. 1986. Estatística geral. Estatística Experimental. Universidade Federal de Pelotas, Brasil.
Steel, R.G., y J.H. Torrie. 1980. Principles and procedures of statistics. A biometrical approach. 2nd ed. Mc Graw-Hill, NY, USA.
Taylor, S.L., M.E. Payton, y W.R. Raun. 1999. Relationship between mean yield, coefficient of variation, mean square error and plot size in wheat field experiments. Commun. Soil Sci. Plant Anal 30:1439-1447.
Vargas, M., E. Combs, G. Alvarado, G. Atlin, K. Mathews, y J. Crossa. 2013. META: A suite of SAS Programs to analyze multi environment breeding trials. Agron. J. 105:11-19.
Vásquez, E.R., y A. Caballero. 2011. Inconsistencia del coeficiente de variación para expresar la variabilidad de un experimento en un modelo de análisis de varianza. Cultivos Tropicales 32(3):42-45.
Yan, W., y J.B. Holland. 2010. A heritability-adjusted GGE Biplot for test environmental evaluation. Euphytica 171:355-369.
Published
How to Cite
Issue
Section
License
1. Proposed policy for open access journals
Authors who publish in this journal accept the following conditions:
a. Authors retain the copyright and assign to the journal the right to the first publication, with the work registered under the attribution, non-commercial and no-derivative license from Creative Commons, which allows third parties to use what has been published as long as they mention the authorship of the work and upon first publication in this journal, the work may not be used for commercial purposes and the publications may not be used to remix, transform or create another work.
b. Authors may enter into additional independent contractual arrangements for the non-exclusive distribution of the version of the article published in this journal (e.g., including it in an institutional repository or publishing it in a book) provided that they clearly indicate that the work was first published in this journal.
c. Authors are permitted and encouraged to publish their work on the Internet (e.g. on institutional or personal pages) before and during the review and publication process, as it may lead to productive exchanges and faster and wider dissemination of published work (see The Effect of Open Access).
