agridat (version 1.23)

gilmour.slatehall: Slate Hall Farm 1978

Description

Yields for a trial at Slate Hall Farm in 1978.

Format

A data frame with 150 observations on the following 5 variables.

row

row

col

column

yield

yield (grams/plot)

gen

genotype factor, 25 levels

rep

rep factor, 6 levels

Details

The trial was of spring wheat at Slate Hall Farm in 1978. The experiment was a balanced lattice with 25 varieties in 6 replicates. The 'rep' labels are arbitrary (no rep labels appeared in the source data). Each row within a rep is an incomplete block. The plot size was 1.5 meters by 4 meters.

Field width: 10 plots x 4 m = 40 m

Field length: 15 plots x 1.5 meters = 22.5 m

References

None.

Examples

if (FALSE) {

  library(agridat)
  data(gilmour.slatehall)
  dat <- gilmour.slatehall

  libs(desplot)
  desplot(dat, yield ~ col * row,
          aspect=22.5/40, num=gen, out1=rep, cex=1,
          main="gilmour.slatehall")


  if(require("asreml", quietly=TRUE)) {

    libs(asreml,lucid)

    # Model 4 of Gilmour et al 1997
    dat <- transform(dat, xf=factor(col), yf=factor(row))
    dat <- dat[order(dat$xf, dat$yf), ]
    m4 <- asreml(yield ~ gen + lin(row), data=dat,
                 random = ~ dev(row) + dev(col),
                 resid = ~ ar1(xf):ar1(yf))
    # coef(m4)$fixed[1] # linear row
    # [1] 31.72252 # (sign switch due to row ordering)
    
    lucid::vc(m4)
    ##       effect component std.error z.ratio bound 
    ##     dev(col)  2519      1959         1.3     P   0
    ##     dev(row) 20290     10260         2       P   0
    ##     xf:yf(R) 23950      4616         5.2     P   0
    ## xf:yf!xf!cor     0.439     0.113     3.9     U   0
    ## xf:yf!yf!cor     0.125     0.117     1.1     U   0
    
    plot(varioGram(m4), main="gilmour.slatehall")
  }
  
}