Multi-environment trial of perennial ryegrass in France

Plant strength of perennial ryegrass in France for 21 genotypes at 7 locations.

Format

A data frame with 147 observations on the following 3 variables.

gen: genotype, 21 levels
loc: location, 7 levels
strength: average plant strength * 100

Details

INRA conducted a breeding trial in western France with 21 genotypes at 7 locations. The observed data is 'strength' averaged over 7-10 plants per plot and three plots per location (after adjusting for blocking effects). Each plant was scored on a scale 0-9.

The original data had a value of 86.0 for genotype G1 at location L4–this was replaced by an additive estimated value of 361.2 as in Gower and Hand (1996).

Source

Jean-Baptiste Denis and John C. Gower, 1996. Asymptotic confidence regions for biadditive models: interpreting genotype-environment interaction, Applied Statistics, 45, 479-493. https://doi.org/10.2307/2986069

References

Gower, J.C. and Hand, D.J., 1996. Biplots. Chapman and Hall.

Examples

if (FALSE) { # \dontrun{

library(agridat)
data(denis.ryegrass)
dat <- denis.ryegrass

# biplots (without ellipses) similar to Denis figure 1
libs(gge)
m1 <- gge(dat, strength ~ gen*loc, scale=FALSE)
biplot(m1, main="denis.ryegrass biplot")

} # }