Multi-environment trial of wheat to illustrate stability statistics

Multi-environment trial to illustrate stability statistics

Usage

data("huehn.wheat")

Format

A data frame with 200 observations on the following 3 variables.

gen: genotype
env: environment
yield: yield dt/ha

Details

Yields for a winter-wheat trial of 20 genotypes at 10 environments.

Note: Huehn 1979 does not use genotype-centered data when calculating stability statistics.

Source

Manfred Huehn (1979). Beitrage zur Erfassung der phanotypischen Stabilitat I. Vorschlag einiger auf Ranginformationen beruhenden Stabilitatsparameter. EDV in Medizin und Biologie, 10 (4), 112-117. Table 1. https://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-145979

References

Nassar, R and Huehn, M. (1987). Studies on estimation of phenotypic stability: Tests of significance for nonparametric measures of phenotypic stability. Biometrics, 43, 45-53.

Examples

if (FALSE) { # \dontrun{

  library(agridat)
  data(huehn.wheat)
  dat <- huehn.wheat
  
  # Nassar & Huehn, p. 51 "there is no evidence for differences in stability
  # among the 20 varieties".
  libs(gge)
  m1 <- gge(dat, yield ~ gen*env)
  biplot(m1, main="huehn.wheat")
  
  libs(reshape2)
  datm <- acast(dat, gen~env, value.var='yield')

  apply(datm,1,mean) # Gen means match Huehn 1979 table 1
  apply(datm,2,mean) # Env means
  apply(datm, 2, rank) # Ranks match Huehn table 1

  # Huehn 1979 did not use genotype-centered data, and his definition
  # of S2 is different from later papers.

  # I'm not sure where 'huehn' function is found
  # apply(huehn(datm, corrected=FALSE), 2, round,2) # S1 matches Huehn
  ##          MeanRank   S1
  ## Jubilar      6.70 3.62
  ## Diplomat     8.35 5.61
  ## Caribo      11.20 6.07
  ## Cbc710      13.65 6.70

  # Very close match to Nassar & Huehn 1987 table 4.
  # apply(huehn(datm, corrected=TRUE), 2, round,2)
  ##          MeanRank   S1   Z1    S2   Z2
  ## Jubilar      10.2 4.00 5.51 11.29 4.29
  ## Diplomat     11.0 6.31 0.09 27.78 0.27
  ## Caribo       10.6 6.98 0.08 34.49 0.01
  ## Cbc710       10.9 8.16 1.78 47.21 1.73

} # }