gauch.soy {agridat} | R Documentation

## Multi-environment trial of soybeans in New York, 1977 to 1988

### Description

New York soybean yields, 1977 to 1988, for 7 genotypes in 55 environments.

### Format

A data frame with 1454 observations on the following 4 variables.

`yield`

  yield, kg/ha

`rep`

  repeated measurement

`gen`

  genotype, 7 levels

`env`

  environment, 55 levels

### Details

Soybean yields at 13 percent moisture for 7 genotypes in 55 environments with 4 replicates. Some environments had only 2 or 3 replicates. The experiment was an RCB design, but some plots were missing and there were many other soybean varieties in the experiment. The replications appear in random order and do _NOT_ define blocks. Environment names are a combination of the first letter of the location name and the last two digits of the year. The location codes are C=Chazy, N=Canton, L=Lockport, G=Geneseo, R=Romulus, A=Aurora, I=Ithica, V=Valatie, D=Riverhead. Plots were 7.6 m long, four rows wide (middle two rows were harvested).

This data has been widely used (in various subsets) to promote the benefits of AMMI (Additive Main Effects Multiplicative Interactions) analyses.

The gen x env means of Table 1 (Zobel et al 1998) are least-squares means (personal communication).

### Source

Retrieved Sep 2011 from http://www.microcomputerpower.com/matmodel/matmodelmatmodel_sample_.html

Used with permission of Hugh Gauch.

### References

Zobel, RW and Wright, MJ and Gauch Jr, HG. 1998. Statistical analysis of a yield trial, Agronomy journal, 80, 388-393. https://doi.org/10.2134/agronj1988.00021962008000030002x

### Examples

    data(gauch.soy)
    dat <- gauch.soy

    # AMMI biplot
    if(require(agricolae)){
      # Figure 1 of Zobel et al 1988, means vs PC1 score
      dat2 <- droplevels(subset(dat, is.element(env, c("A77","C77","V77",
      "V78","A79","C79","G79","R79","V79","A80","C80","G80","L80","D80",
      "R80","V80","A81","C81","G81","L81","D81","R81","V81","A82","L82",
      "G82","V82","A83","I83","G83","A84","N84","C84","I84","G84"))))

      m2 <- with(dat2, AMMI(env, gen, rep, yield))
      bip <- m2$biplot
      with(bip, plot(yield, PC1, type='n', main="gauch.soy -- AMMI biplot"))
      with(bip, text(yield, PC1, rownames(bip),
                     col=ifelse(bip$type=="GEN", "darkgreen", "blue"),
                     cex=ifelse(bip$type=="GEN", 1.5, .75)))
    }

[Package agridat version 1.16 Index]