agridat (version 1.23)

damesa.maize: Incomplete-block experiment of maize in Ethiopia.

Description

Incomplete-block experiment of maize in Ethiopia.

Usage

data("damesa.maize")

Format

A data frame with 264 observations on the following 8 variables.

site

site, 4 levels

rep

replicate, 3 levels

block

incomplete block

plot

plot number

gen

genotype, 22 levels

row

row ordinate

col

column ordinate

yield

yield, t/ha

Details

An experiment harvested in 2012, evaluating drought-tolerant maize hybrids at 4 sites in Ethiopia. At each site, an incomplete-block design was used.

Damesa et al use this data to compare single-stage and two-stage analyses.

References

None

Examples

if (FALSE) {
  library(agridat)
  data(damesa.maize)
  libs(desplot)
  desplot(damesa.maize,
          yield ~ col*row|site,
          main="damesa.maize",
          out1=rep, out2=block, num=gen, cex=1)

  if(require("asreml", quietly=TRUE)) {
    # Fit the single-stage model in Damesa
    libs(asreml,lucid)
    m0 <- asreml(data=damesa.maize,
                 fixed = yield ~ gen,
                 random = ~ site + gen:site + at(site):rep/block,
                 residual = ~ dsum( ~ units|site) )
    lucid::vc(m0) # match Damesa table 1 column 3
    ##                 effect component std.error z.ratio bound 
    ##       at(site, S1):rep   0.08819   0.1814     0.49     P 0  
    ##       at(site, S2):rep   1.383     1.426      0.97     P 0  
    ##       at(site, S3):rep   0              NA      NA     B 0  
    ##       at(site, S4):rep   0.01442   0.02602    0.55     P 0  
    ##                   site  10.45      8.604      1.2      P 0.1
    ##               gen:site   0.1054    0.05905    1.8      P 0.1
    ## at(site, S1):rep:block   0.3312    0.3341     0.99     P 0  
    ## at(site, S2):rep:block   0.4747    0.1633     2.9      P 0  
    ## at(site, S3):rep:block   0              NA      NA     B 0  
    ## at(site, S4):rep:block   0.06954   0.04264    1.6      P 0  
    ##              site_S1!R   1.346     0.3768     3.6      P 0  
    ##              site_S2!R   0.1936    0.06628    2.9      P 0  
    ##              site_S3!R   1.153     0.2349     4.9      P 0  
    ##              site_S4!R   0.1112    0.03665    3        P 0  
  }
  
}