Uniformity trial of barley in Germany
A data frame with 1080 observations on the following 5 variables.
yield 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
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## 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) ## End(Not run)
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