Multi-environment trial of corn, balanced incomplete block design
Balanced incomplete block design in corn
A data frame with 52 observations on the following 3 variables.
loclocation/block, 13 levels
gengenotype/line, 13 levels
yieldyield, pounds/plot
Incomplete block design. Each loc/block has 4 genotypes/lines. The blocks are planted at different locations.
Conducted in 1943 in North Carolina.
North Carolina Agricultural Experiment Station, United States Department of Agriculture.
Cochran, W.G. and Cox, G.M. (1957), Experimental Designs, 2nd ed., Wiley and Sons, New York, p. 448.
library(agridat)
data(cochran.bib)
dat <- cochran.bib
# Show the incomplete-block structure
libs(lattice)
redblue <- colorRampPalette(c("firebrick", "lightgray", "#375997"))
levelplot(yield~loc*gen, dat,
col.regions=redblue,
xlab="loc (block)", main="cochran.bib - incomplete blocks")
with(dat, table(gen,loc))
rowSums(as.matrix(with(dat, table(gen,loc))))
colSums(as.matrix(with(dat, table(gen,loc))))
m1 = aov(yield ~ gen + Error(loc), data=dat)
summary(m1)
libs(nlme)
m2 = lme(yield ~ -1 + gen, data=dat, random=~1|loc)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.