archbold.apple {agridat} | R Documentation

## Split-split plot experiment on apple trees

### Description

Split-split plot experiment on apple trees with different spacing, root stock, and cultivars.

### Format

A data frame with 120 observations on the following 10 variables.

`rep`

  block, 5 levels

`row`

  row

`pos`

  position within each row

`spacing`

  spacing between trees, 6,10,14 feet

`stock`

  rootstock, 4 levels

`gen`

  genotype, 2 levels

`yield`

  yield total, kg/tree from 1975-1979

`trt`

  treatment code

### Details

In rep 1, the 10-foot-spacing main plot was split into two non-contiguous pieces. This also happened in rep 4. In the analysis of Cornelius and Archbold, they consider each row x within-row-spacing to be a distinct main plot. (Also true for the 14-foot row-spacing, even though the 14-foot spacing plots were contiguous.)

The treatment code is defined as 100 * spacing + 10 * stock + gen, where stock=0,1,6,7 for Seedling,MM111,MM106,M0007 and gen=1,2 for Redspur,Golden, respectively.

### Source

D Archbold and G. R. Brown and P. L. Cornelius. (1987). Rootstock and in-row spacing effects on growth and yield of spur-type delicious and Golden delicious apple. Journal of the American Society for Horticultural Science, 112, 219-222.

### References

Cornelius, PL and Archbold, DD, 1989. Analysis of a split-split plot experiment with missing data using mixed model equations. Applications of Mixed Models in Agriculture and Related Disciplines. Pages 55-79.

### Examples

    data(archbold.apple)
    dat <- archbold.apple

    # Define main plot and subplot
    dat <- transform(dat, rep=factor(rep), spacing=factor(spacing), trt=factor(trt),
                     mp = factor(paste(row,spacing,sep="")),
                     sp = factor(paste(row,spacing,stock,sep="")))

    # Due to 'spacing', the plots are different sizes, but the following layout
    # shows the relative position of the plots and treatments. Note that the
    # 'spacing' treatments are not contiguous in some reps.
    if(require(desplot)){
      desplot(spacing~row*pos, dat,
              col=stock, cex=1, num=gen, # aspect unknown
              main="archbold.apple")
    }

    ## Not run:
      require("lme4")
      require("lucid")

      m1 <- lmer(yield ~ -1 + trt + (1|rep/mp/sp), dat)

      vc(m1)  # Variances/means on Cornelius, page 59
      ##         grp        var1 var2   vcov sdcor
      ## sp:(mp:rep) (Intercept) <NA>  193.3 13.9
      ##      mp:rep (Intercept) <NA>  203.8 14.28
      ##         rep (Intercept) <NA>  197.3 14.05
      ##    Residual        <NA> <NA> 1015   31.86

    ## End(Not run)

[Package agridat version 1.16 Index]