Analysis of factorial experiments for agronomical reseach using Infostat

Authors

DOI:

https://doi.org/10.36958/sep.v7i2.299

Keywords:

factorial experiment, statistical software, analysis of variance, mean difference test, polynomial regression

Abstract

OBJECTIVE: to show researchers the statistical analysis of a two-factor experiment using software. METHOD: In the description, oat yield data are used, grown on three sowing dates and four nitrogen levels, in a randomized complete block design and combinatorial arrangement.The analysis of variance (ANOVA), verification of assumptions, interaction graph and post-ANOVA analysis were performed; using the Infostat v.2020® software. To verify the assumptions of the statistical model, the Shapiro-Wilk test was used (to verify normality) and the scatter graph between predicted values and studentized residuals (to verify homoscedasticity and independence). The DGC comparison of means was used as a post-ANOVA test. RESULTS: The summary table of the ANOVA for a two-factor experiment was generated in Infostat v.2020® along with the coefficient of variation (CV) value as an indicator of the precision of the experiment. The main factors and the interaction were significant. The p values associated with the dates, nitrogen levels, and interaction were <0.0001, 0.0034, and 0.0325. The CV was 24.67%, with a confidence interval generated by simulation of 22.27-27.07%. In the review of assumptions, these were met. According to the DGC test, the best yields were obtained on the first sowing date, and when nitrogen was applied, generating a quadratic model. CONCLUSION: The use of software allows for easy, fast, and reliable analysis. It is also possible to have more time for the interpretation of the ANOVA results.

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Author Biographies

español, Universidad de San Carlos de Guatemala


He is an Agricultural Engineer. Doctor of Sciences. Professor of the Subarea of ​​Quantification and Research Methods of the Faculty of Agronomy, USAC.

Byron Humberto González Ramírez, Universidad de San Carlos de Guatemala


He is an Agricultural Engineer. Ph. D., Professor and Director of the Telematics Center (CETE) of the Faculty of Agronomy, USAC.

References

Balzarini, M., González, L., Tablada, M., Casanoves, F., Di Rienzo, J., & Robledo, C. (2008). Infostat. Manual del Usuario. Editorial Brujas.

https://repositorio.catie.ac.cr/bitstream/handle/11554/10346/Manual_INFOSTAT_2008.pdf

Di Rienzo, J., Cassanoves, F., Balzarini, M., González, L., Tablada, M., & Robledo, C. (2020). Infostat (Versión 2020) [Software]. Centro de Transferencia InfoStat. http://www.infostat.com.ar

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Fisher, R. (1926). The arrangement of field experiments. 33, 503–515.

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Parmar, R. S., Kathiriya, D. R., & Kamani, G. J. (2022). Analysis of factorial experiments for agricultural reseach using digital tools. Gujarat Journal of Extension Education, 33(1), 150–154. https://doi.org/10.56572/gjoee.2022.33.1.0030

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Published

28-11-2024

How to Cite

español, & González Ramírez, B. H. (2024). Analysis of factorial experiments for agronomical reseach using Infostat . Revista Cientí­fica Del Sistema De Estudios De Postgrado De La Universidad De San Carlos De Guatemala, 7(2), 17–30. https://doi.org/10.36958/sep.v7i2.299

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Scientific articles

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