diff --git a/R/legTools.R b/R/legTools.R
index 9cbf85efaf28c1ebaf3aeaac5f4e87fc74f85159..1302641f0c16b908059c599420ab21817f073fb7 100644
--- a/R/legTools.R
+++ b/R/legTools.R
@@ -206,3 +206,44 @@ NULL
 #'     layer(panel.abline(a=0, b=1, lty=2))
 #'
 NULL
+
+#' @name cassavaYield
+#'
+#' @title Cassava variety competition experiment
+#'
+#' @description These data are from an experiment done by The Brazilian
+#'     Agricultural Research Corporation in Cassava & Tropical Fruits
+#'     (Centro Nacional de Pesquisa da Mandioca e Fruticultura da
+#'     Embrapa) at Cruz das Almas, Bahia. The experiment was done in a
+#'     randomized complete block design with 4 blocks. Cassava yield
+#'     (t/ha) was recorded in each experimental unit.
+#'
+#' \itemize{
+#'     \item \code{block} a categorical unordered factor with 4 levels.
+#'     \item \code{variety} a categorical unordered factor with 6
+#'     levels.
+#'     \item \code{yield} cassava yield (t/ha).
+#' }
+#'
+#' @docType data
+#'
+#' @keywords datasets
+#'
+#' @usage data(cassavaYield)
+#'
+#' @format a \code{data.frame} with 24 records and 3 variables.
+#'
+#' @source Frederico, P. (2009). Curso de Estatística Experimental (15th
+#'     ed.). Piracicaba, São Paulo: FEALQ. (page 93)
+#'
+#' @examples
+#' 
+#' require(lattice)
+#' data(cassavaYield)
+#'
+#' plot(yield~variety, data=cassavaYield,
+#'      groups=block, type="o",
+#'      ylab=expression(Yield~(t~ha^{-1})),
+#'      xlab="Variety")
+#'
+NULL
diff --git a/data-raw/cassavaYield.R b/data-raw/cassavaYield.R
new file mode 100644
index 0000000000000000000000000000000000000000..249177652586b7e681d46791e5c219d2c827688f
--- /dev/null
+++ b/data-raw/cassavaYield.R
@@ -0,0 +1,38 @@
+##----------------------------------------------------------------------
+## Data generation.
+
+cassavaYield <- read.table("http://www.leg.ufpr.br/~walmes/data/pimentel_mandioca.txt",
+                           header=TRUE, sep="\t")
+names(cassavaYield) <- c("block", "variety", "yield")
+str(cassavaYield)
+
+cassavaYield <- cassavaYield[with(cassavaYield, order(block, variety)),]
+
+save(cassavaYield, file="../data/cassavaYield.RData")
+
+##----------------------------------------------------------------------
+## Examples.
+
+require(lattice)
+
+xyplot(yield~variety, data=cassavaYield,
+       groups=block, type="o",
+       ylab=expression(Yield~(t~ha^{-1})),
+       xlab="Variety")
+
+rm(list=ls())
+load("../data/cassavaYield.RData")
+ls()
+str(cassavaYield)
+
+m0 <- lm(yield~block+variety, data=cassavaYield)
+
+## Accessing the model assumptions.
+par(mfrow=c(2,2)); plot(m0); layout(1)
+
+## ANOVA table.
+anova(m0)
+
+library(doBy)
+ls <- LSmatrix(m0, effect="variety")
+dput(ls)
diff --git a/data/cassavaYield.RData b/data/cassavaYield.RData
new file mode 100644
index 0000000000000000000000000000000000000000..07cdb35446a418b6d57821875406864be2fff9a8
Binary files /dev/null and b/data/cassavaYield.RData differ
diff --git a/man/cassavaYield.Rd b/man/cassavaYield.Rd
new file mode 100644
index 0000000000000000000000000000000000000000..186defb34cb6dcf075fa1fe87ecfb4d728d8e937
--- /dev/null
+++ b/man/cassavaYield.Rd
@@ -0,0 +1,40 @@
+% Generated by roxygen2 (4.1.1): do not edit by hand
+% Please edit documentation in R/legTools.R
+\docType{data}
+\name{cassavaYield}
+\alias{cassavaYield}
+\title{Cassava variety competition experiment}
+\format{a \code{data.frame} with 24 records and 3 variables.}
+\source{
+Frederico, P. (2009). Curso de Estatística Experimental (15th
+    ed.). Piracicaba, São Paulo: FEALQ. (page 93)
+}
+\usage{
+data(cassavaYield)
+}
+\description{
+These data are from an experiment done by The Brazilian
+    Agricultural Research Corporation in Cassava & Tropical Fruits
+    (Centro Nacional de Pesquisa da Mandioca e Fruticultura da
+    Embrapa) at Cruz das Almas, Bahia. The experiment was done in a
+    randomized complete block design with 4 blocks. Cassava yield
+    (t/ha) was recorded in each experimental unit.
+
+\itemize{
+    \item \code{block} a categorical unordered factor with 4 levels.
+    \item \code{variety} a categorical unordered factor with 6
+    levels.
+    \item \code{yield} cassava yield (t/ha).
+}
+}
+\examples{
+require(lattice)
+data(cassavaYield)
+
+plot(yield~variety, data=cassavaYield,
+     groups=block, type="o",
+     ylab=expression(Yield~(t~ha^{-1})),
+     xlab="Variety")
+}
+\keyword{datasets}
+