Uniformity trial of barley
Uniformity trial of barley in Germany
data("piepho.barley.uniformity")A data frame with 1080 observations on the following 5 variables.
rowrow ordinate
colcolumn ordinate
yieldyield per plot
Uniformity trial of barley at Ihinger Hof farm, conducted by the University of Hohenheim, Germany, in 2007.
Note: The paper by Piepho says "The trial had 30 rows and 36 columns. Plot widths were 1.90 m along rows and 3.73 m along columns." However, the SAS code supplement to the paper, called "PBR_1654_sm_example1.sas", has row=1-36, col=1-30. We cannot determine which dimension is "row" and which is "column", and therefore cannot determine the actual dimensions of the field.
H. P. Piepho & E. R. Williams (2010). Linear variance models for plant breeding trials. Plant Breeding, 129, 1-8. https://doi.org/10.1111/j.1439-0523.2009.01654.x
None
## Not run:
data(piepho.barley.uniformity)
dat <- piepho.barley.uniformity
libs(desplot)
desplot(yield ~ col*row, dat,
tick=TRUE, # aspect unknown
main="piepho.barley.uniformity.csv")
libs(asreml,dplyr)
dat <- mutate(dat, x=factor(col), y=factor(row))
dat <- arrange(dat, x, y)
# Piepho AR1xAR1 model (in random term, NOT residual)
m1 <- asreml(data=dat,
yield ~ 1,
random = ~ x + y + ar1(x):ar1(y),
residual = ~ units,
na.action=na.method(x="keep") )
m1 <- update(m1)
# Match Piepho table 3, footnote 4: .9671, .9705 for col,row correlation
# Note these parameters are basically at the boundary of the parameter
# space. Questionable fit.
libs(lucid)
lucid::vc(m1)
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