george.wheat.Rd
Multi-location/year breeding trial in California
data("george.wheat")
A data frame with 13996 observations on the following 5 variables.
gen
genotype number
year
year
loc
location
block
block
yield
yield per plot
This is a nice example of data from a breeding trial, in which some check genotypes are kepts during the whole experiment, while other genotypes enter and leave the breeding program. The data is highly unbalanced with respect to genotypes-by-environments.
Results of late-stage small-trials of 211 genotypes of wheat in California, conducted at 9 locations during the years 2004-2018.
Each trial was an RCB with 4 blocks.
The authors used this data to look at GGE biplots across years and concluded that repeatable genotype-by-location patterns were weak, and therefore the California cereal production region is a large, unstable, mega-environment.
Data downloaded 2019-10-29 from Dryad, https://doi.org/10.5061/dryad.bf8rt6b. Data are public domain.
Nicholas George and Mark Lundy (2019). Quantifying Genotype x Environment Effects in Long-Term Common Wheat Yield Trials from an Agroecologically Diverse Production Region. Crop Science, 59, 1960-1972. https://doi.org/10.2135/cropsci2019.01.0010
None
# \dontrun{ library(agridat) libs(lattice, reshape2) data(george.wheat) dat <- george.wheat dat$env <- paste0(dat$year, ".", dat$loc) # average reps, cast to matrix mat <- reshape2::acast(dat, gen ~ env, value.var="yield", fun=mean, na.rm=TRUE) lattice::levelplot(mat, aspect="m", main="george.wheat", xlab="genotype", ylab="environment", scales=list(x=list(cex=.3,rot=90),y=list(cex=.5)))# }