<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>1659-4266</journal-id>
<journal-title><![CDATA[Cuadernos de Investigación UNED]]></journal-title>
<abbrev-journal-title><![CDATA[Cuadernos de Investigación UNED]]></abbrev-journal-title>
<issn>1659-4266</issn>
<publisher>
<publisher-name><![CDATA[Universidad Estatal a Distancia de Costa Rica]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S1659-42662019000300355</article-id>
<article-id pub-id-type="doi">10.22458/urj.v11i3.2653</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Tamaño y forma de unidad experimental para ensayos de rendimiento de arroz (Oryza sativa), en Guanacaste, Costa Rica]]></article-title>
<article-title xml:lang="en"><![CDATA[Size and shape of experimental units for rice (Oryza sativa) yield trials, in Guanacaste, Costa Rica]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Vargas Rojas]]></surname>
<given-names><![CDATA[Jorge Claudio]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Navarro Flores]]></surname>
<given-names><![CDATA[Juan Ramón]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad de Costa Rica  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Costa Rica</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Universidad de Costa Rica  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Costa Rica</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>12</month>
<year>2019</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>12</month>
<year>2019</year>
</pub-date>
<volume>11</volume>
<numero>3</numero>
<fpage>355</fpage>
<lpage>360</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.sa.cr/scielo.php?script=sci_arttext&amp;pid=S1659-42662019000300355&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.sa.cr/scielo.php?script=sci_abstract&amp;pid=S1659-42662019000300355&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.sa.cr/scielo.php?script=sci_pdf&amp;pid=S1659-42662019000300355&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen Introducción: El tamaño y forma de la unidad experimental afecta la precisión en los resultados de ensayos de campo. Objetivo: Determinar el tamaño y la forma de unidad experimental apropiados para ensayos de rendimiento en arroz en Bagaces, Guanacaste, Costa Rica. Métodos: Empleamos un análisis de regresión múltiple a los datos de un ensayo de uniformidad. La variabilidad residual, medida como coeficiente de variación (y relacionada a los diferentes tamaños y formas de unidad experimental replicable) fue modelada en función del largo y ancho. El siguiente paso fue estimar las derivadas parciales para cada regresora e igualarlas a -1. Al resolver este sistema de ecuaciones es posible obtener la combinación de ancho y largo de unidad de experimental que minimiza el coeficiente de variación. Resultados: Para este trabajo, esa combinación resultó ser de 2,93m de largo por 7,95m de ancho. Conclusión: En términos prácticos, el tamaño de unidad experimental que minimiza el coeficiente de variación es de 3m de largo por 8m de ancho.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract &#8220;Size and shape of experimental units for rice (Oryza sativa) yield trials, in Guanacaste, Costa Rica&#8221;.Introduction: The size and shape of an experimental unit affect the accuracy of field trials. Objective: Finding the appropriate size and shape of an experimental unit for rice yield trials in Bagaces, Guanacaste, Costa Rica. Methods: We applied a multiple regression analysis to data from an uniformity trial. The residual variability, measured as a coefficient of variation (and related to different sizes and forms of a replicable experimental unit), was modeled according to length and width. The next step was to determine partial derivatives per regressor and adjust them to -1. With the equation system it is possible to obtain a combination of width and length which decreases the coefficient of variation. Results: For this work, the resulting combination was 2,93m long by 7,95m wide. Conclusion: In practical terms, the size of the experimental unit that decreases the coefficient of variation is 3m long and 8m wide.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[Plot size]]></kwd>
<kwd lng="en"><![CDATA[plot shape]]></kwd>
<kwd lng="en"><![CDATA[rice]]></kwd>
<kwd lng="en"><![CDATA[multiple regression]]></kwd>
<kwd lng="en"><![CDATA[experimental error]]></kwd>
<kwd lng="es"><![CDATA[Tamaño de unidad experimental]]></kwd>
<kwd lng="es"><![CDATA[forma de unidad experimental]]></kwd>
<kwd lng="es"><![CDATA[arroz]]></kwd>
<kwd lng="es"><![CDATA[regresión múltiple]]></kwd>
<kwd lng="es"><![CDATA[error experimental]]></kwd>
</kwd-group>
</article-meta>
</front><back>
<ref-list>
<ref id="B1">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Álvarez]]></surname>
<given-names><![CDATA[R.]]></given-names>
</name>
<name>
<surname><![CDATA[Soto]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
<name>
<surname><![CDATA[Gómez]]></surname>
<given-names><![CDATA[H.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Tamaño de parcela y número de repeticiones para estimar una población de Spodoptera frugiperda (Smith) y su daño en maíz.]]></article-title>
<source><![CDATA[Revista Facultad Nacional de Agronomía]]></source>
<year>1986</year>
</nlm-citation>
</ref>
<ref id="B2">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Asif-Masood]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
<name>
<surname><![CDATA[Raza]]></surname>
<given-names><![CDATA[I.]]></given-names>
</name>
<name>
<surname><![CDATA[Yaseen]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Estimation of optimum field plot size and shape in paddy yield trial.]]></article-title>
<source><![CDATA[Pakistan Journal of Agricultural Research]]></source>
<year>2012</year>
</nlm-citation>
</ref>
<ref id="B3">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Barrientos-García]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
</person-group>
<source><![CDATA[Evaluación de 4 métodos para la determinación de tamaño y forma óptimos de parcela para experimentación agrícola]]></source>
<year>1981</year>
<publisher-name><![CDATA[Universidad de San Carlos, San Carlos, Guatemala.]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B4">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Barros]]></surname>
<given-names><![CDATA[I.]]></given-names>
</name>
<name>
<surname><![CDATA[Tavares]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Estimativa do tamanho ótimo de parcelas experimentais através de cálculos algébricos.]]></article-title>
<source><![CDATA[Bragantia]]></source>
<year>1995</year>
</nlm-citation>
</ref>
<ref id="B5">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Box]]></surname>
<given-names><![CDATA[G. E.]]></given-names>
</name>
<name>
<surname><![CDATA[Hunter]]></surname>
<given-names><![CDATA[J. S.]]></given-names>
</name>
<name>
<surname><![CDATA[Hunter]]></surname>
<given-names><![CDATA[W. G.]]></given-names>
</name>
</person-group>
<source><![CDATA[Wiley-Interscience]]></source>
<year>2005</year>
</nlm-citation>
</ref>
<ref id="B6">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Chacín]]></surname>
<given-names><![CDATA[F.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Tamaño de parcela experimental y su forma.]]></article-title>
<source><![CDATA[Revista de la Facultad de Agronomía de Maracay]]></source>
<year>1977</year>
</nlm-citation>
</ref>
<ref id="B7">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Da Silva]]></surname>
<given-names><![CDATA[C. W.]]></given-names>
</name>
</person-group>
<source><![CDATA[Comparacao de métodos para estimar o tamaño ótimo de parcela embananeira]]></source>
<year>2010</year>
<publisher-name><![CDATA[Universidad Federal de Vicosa, Vicosa, Brasil.]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B8">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Gomez]]></surname>
<given-names><![CDATA[K. A.]]></given-names>
</name>
</person-group>
<source><![CDATA[International Rice Research Institute]]></source>
<year>1972</year>
</nlm-citation>
</ref>
<ref id="B9">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Gomez]]></surname>
<given-names><![CDATA[K.]]></given-names>
</name>
<name>
<surname><![CDATA[Gomez]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
</person-group>
<source><![CDATA[Wiley-Interscience]]></source>
<year>1984</year>
</nlm-citation>
</ref>
<ref id="B10">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Lorentz]]></surname>
<given-names><![CDATA[L. H.]]></given-names>
</name>
<name>
<surname><![CDATA[Boligon]]></surname>
<given-names><![CDATA[A. A.]]></given-names>
</name>
<name>
<surname><![CDATA[Storck]]></surname>
<given-names><![CDATA[L.]]></given-names>
</name>
<name>
<surname><![CDATA[Lúcio]]></surname>
<given-names><![CDATA[A. D.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Plot size and experimental precision for sunflower production]]></article-title>
<source><![CDATA[Scientia Agricola]]></source>
<year>2010</year>
</nlm-citation>
</ref>
<ref id="B11">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Oliveira]]></surname>
<given-names><![CDATA[S. J.]]></given-names>
</name>
<name>
<surname><![CDATA[Storck]]></surname>
<given-names><![CDATA[L.]]></given-names>
</name>
<name>
<surname><![CDATA[Lopes]]></surname>
<given-names><![CDATA[S. J.]]></given-names>
</name>
<name>
<surname><![CDATA[Lúcio]]></surname>
<given-names><![CDATA[A. D.]]></given-names>
</name>
<name>
<surname><![CDATA[Feijó]]></surname>
<given-names><![CDATA[S.]]></given-names>
</name>
<name>
<surname><![CDATA[Damo]]></surname>
<given-names><![CDATA[H. P.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Plot size and experimental unit relationship in exploratory experiments.]]></article-title>
<source><![CDATA[Scientia Agricola]]></source>
<year>2005</year>
</nlm-citation>
</ref>
<ref id="B12">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Párraga]]></surname>
<given-names><![CDATA[C.]]></given-names>
</name>
<name>
<surname><![CDATA[Chacín]]></surname>
<given-names><![CDATA[F.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Comparación de metodologías univariadas en la determinación de unidades experimentales de campo: renglón maíz (Zea mays L.).]]></article-title>
<source><![CDATA[Revista Facultad de Agronomía de Maracay]]></source>
<year>2000</year>
</nlm-citation>
</ref>
<ref id="B13">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Rodríguez]]></surname>
<given-names><![CDATA[N.]]></given-names>
</name>
<name>
<surname><![CDATA[Sánchez]]></surname>
<given-names><![CDATA[H.]]></given-names>
</name>
<name>
<surname><![CDATA[Pacheco]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Determinación de tamaño y forma óptimos de parcela para ensayos de rendimiento con café]]></article-title>
<source><![CDATA[Revista Colombiana de Estadística]]></source>
<year>1993</year>
</nlm-citation>
</ref>
<ref id="B14">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Rosselló]]></surname>
<given-names><![CDATA[J. M.]]></given-names>
</name>
<name>
<surname><![CDATA[Fernández]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
</person-group>
<source><![CDATA[FAO]]></source>
<year>1986</year>
</nlm-citation>
</ref>
<ref id="B15">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Sánchez Hernández]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
<name>
<surname><![CDATA[Mejía Contreras]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<name>
<surname><![CDATA[Villanueva Verduzco]]></surname>
<given-names><![CDATA[c.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Determinación del tamaño adecuado de parcela experimental en calabaza pipiana (Cucurbita argyrosperma hubervar. stenosperma).]]></article-title>
<source><![CDATA[Revista Fitotecnia Mexicana]]></source>
<year>2006</year>
</nlm-citation>
</ref>
<ref id="B16">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Santos]]></surname>
<given-names><![CDATA[D.]]></given-names>
</name>
<name>
<surname><![CDATA[Haesbaert]]></surname>
<given-names><![CDATA[F.]]></given-names>
</name>
<name>
<surname><![CDATA[Lúcio]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<name>
<surname><![CDATA[Storck]]></surname>
<given-names><![CDATA[L.]]></given-names>
</name>
<name>
<surname><![CDATA[Cargnelutti]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Tamanho ótimo de parcela para a cultura do feijão-vagem]]></article-title>
<source><![CDATA[Revista Ciência Agronômica]]></source>
<year>2012</year>
</nlm-citation>
</ref>
<ref id="B17">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Stroup]]></surname>
<given-names><![CDATA[W. W.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Power analysis based on spatial effects mixed models: a tool for comparing design and analysis strategies in the presence of spatial variability.]]></article-title>
<source><![CDATA[Journal of Agricultural, Biological, and Environmental Statistics,]]></source>
<year>2002</year>
</nlm-citation>
</ref>
<ref id="B18">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Vallejo]]></surname>
<given-names><![CDATA[R.]]></given-names>
</name>
<name>
<surname><![CDATA[Mendoza]]></surname>
<given-names><![CDATA[H.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Plot technique studies on sweet potato yield trials]]></article-title>
<source><![CDATA[Journal of the American Society for Horticultural Science]]></source>
<year>1992</year>
</nlm-citation>
</ref>
<ref id="B19">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Vargas]]></surname>
<given-names><![CDATA[J. C.]]></given-names>
</name>
<name>
<surname><![CDATA[Navarro]]></surname>
<given-names><![CDATA[J. R.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Determinación de un tamaño adecuado de unidad experimental, utilizando el método de curvatura máxima, para ensayos de arroz (Oryza sativa), en Bagaces, Guanacaste.]]></article-title>
<source><![CDATA[Revista Intersedes]]></source>
<year>2014</year>
</nlm-citation>
</ref>
</ref-list>
</back>
</article>
