SciELO - Scientific Electronic Library Online

vol.51 issue3Best F1 crossbreedings and hybrid reproducers as maternal lines for commercial rabbit production author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand




  • Have no cited articlesCited by SciELO

Related links

  • Have no similar articlesSimilars in SciELO


Cuban Journal of Agricultural Science

Print version ISSN 0864-0408On-line version ISSN 2079-3480


HERRERA, Magaly et al. Comparison of mixed and fixed effects in the analysis of a split plot design in an experiment with Guinea Mombaza (Megathyrsus maximus cv. Mombaza). Cuban J. Agric. Sci. [online]. 2017, vol.51, n.3, pp.285-291. ISSN 0864-0408.

Models of fixed and mixed effects were compared in the analysis of a split plot design in an experiment with Guinea Mombaza (Megathyrsus maximus cv. Mombaza), to know the effectiveness of the mixed model as an analysis alternative. The experiment was carried out with a split plot design, considering the harvest months of Guinea Mombaza as the main plot and one control and two levels of nitrogen fertilization (0, 50 and 75 %) as subplots. Variance-covariance structures tested were Toeplitz, variance component, compound symmetry, Firts order autoregressive  and unstructured variance structure in the mixed model. For a better data fit, Akaike, corrected Akaike and Bayesian information criteria were taken into account, and the lowest value was considered. Variance-covariance structures with the best fit were Toeplitz, component of variance, and unstructured. Probability values of interaction of the main effects were similar for both models, as well as the mean square of the error and standard errors of mean differences. Selection criteria, which were properly fitted to analyzed variables, allowed to know the variance-covariance structure. Mixed model provided standard errors of appropriate mean differences, so it is proposed as an analysis alternative. The use of the mixed model avoids calculation of standard errors based on the formula established for this purpose.

Keywords : variance-covariance; information criteria; random effect; PROC MIXED.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )


Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License