vargas.txe {agridat} | R Documentation

## Treatment x environment interaction in agronomy trials

### Description

Treatment x environment interaction in agronomy trials

### Usage

    data("vargas.txe.covs")
    data("vargas.txe.yield")

### Format

The 'vargas.txe.covs' data has 10 years of measurements on 28 environmental covariates:

`year`

  year

`MTD`

  mean maximum temperature in December

`MTJ`

  mean maximum temperature in January

`MTF`

  mean maximum temperature in February

`MTM`

  mean maximum temperature in March

`MTA`

  mean maximum temperature in April

`mTD`

  mean minimum temperature in December

`mTJ`

  mean minimum temperature in January

`mTF`

  mean minimum temperature in February

`mTM`

  mean minimum temperature in March

`mTA`

  mean minimum temperature in April

`mTUD`

  mean minimum temperature in December

`mTUJ`

  mean minimum temperature in January

`mTUF`

  mean minimum temperature in February

`mTUM`

  mean minimum temperature in March

`mTUA`

  mean minimum temperature in April

`PRD`

  total monthly precipitation in December

`PRJ`

  total monthly precipitation in Jan

`PRF`

  total monthly precipitation in Feb

`PRM`

  total monthly precipitation in Mar

`SHD`

  sun hours per day in Dec

`SHJ`

  sun hours per day in Jan

`SHF`

  sun hours per day in Feb

`EVD`

  total monthly evaporation in Dec

`EVJ`

  total monthly evaporation in Jan

`EVF`

  total monthly evaporation in Feb

`EVM`

  total monthly evaporation in Mar

`EVA`

  total monthly evaporation in Apr

The 'vargas.txe.yield' dataframe contains 240 observations on three variables

`year`

  Year

`trt`

  Treatment. See details section

`yield`

  Grain yield, kg/ha

### Details

The treatment names indicate:

T | deep knife
t | no deep knife
S | sesbania
s | soybean
M | chicken manure
m | no chicken manure
0 | no nitrogen
n | 100 kg/ha nitrogen
N | 200 kg/ha nitrogen

### Source

Vargas, Mateo and Crossa, Jose and van Eeuwijk, Fred and Sayre, Kenneth D. and Reynolds, Matthew P. (2001). Interpreting Treatment x Environment Interaction in Agronomy Trials. Agron. J., 93, 949-960. Table A1, A3. https://doi.org/10.2134/agronj2001.934949x

Used with permission of Jose Crossa.

### Examples

    data(vargas.txe.covs)
    data(vargas.txe.yield)

    if(require(reshape2)){

      require(lattice)
      redblue <- colorRampPalette(c("firebrick", "lightgray", "#375997"))
      Z <- vargas.txe.yield
      Z <- acast(Z, year ~ trt, value.var='yield')
      levelplot(Z, col.regions=redblue,
                main="vargas.txe.yield", xlab="year", ylab="treatment",
                scales=list(x=list(rot=90)))

      # Double-centered like AMMI
      Z <- sweep(Z, 1, rowMeans(Z))
      Z <- sweep(Z, 2, colMeans(Z))
      # Vargas figure 1
      biplot(prcomp(Z, scale.=FALSE), main="vargas.txe.yield")

      # Now, PLS relating the two matrices
      U <- vargas.txe.covs
      U <- scale(U) # Standardized covariates
      require(pls)
      m1 <- plsr(Z~U)
      # Vargas Fig 2, flipped vertical/horizontal
      biplot(m1, which="x", var.axes=TRUE)

    }

[Package agridat version 1.16 Index]