mead.turnip {agridat} | R Documentation

## Density/spacing experiment for turnips in 3 blocks.

### Description

Density/spacing experiment for turnips in 3 blocks.

### Usage

    data("mead.turnip")

### Format

A data frame with 60 observations on the following 4 variables.

`yield`

  log yield (pounds/plot)

`block`

  block

`spacing`

  row spacing, inches

`density`

  density of seeds, pounds/acre

### Details

An experiment with turnips, 3 blocks, 20 treatments in a factorial arrangement of 5 seeding rates (density) and 4 widths (spacing).

### Source

Roger Mead. (1988). The Design of Experiments: Statistical Principles for Practical Applications. Example 12.3. Page 323.

### References

H. P. Piepho, R. N. Edmondson. (2018). A tutorial on the statistical analysis of factorial experiments with qualitative and quantitative treatment factor levels. Jour Agronomy and Crop Science, 8, 1-27. https://doi.org/10.1111/jac.12267

### Examples

    data(mead.turnip)
    dat <- mead.turnip

    dat$ratef <- factor(dat$density)
    dat$widthf <- factor(dat$spacing)

    m1 <- aov(yield ~ block + ratef + widthf + ratef:widthf, data=dat)
    anova(m1) # table 12.10 in Mead

    # Similar to Piepho fig 10
    if(require(lattice)) {
      xyplot(yield ~ log(spacing)|ratef, data=dat,
             auto.key=list(columns=5),
             main="mead.turnip - log(yield) for each density",
             group=ratef)
    }

[Package agridat version 1.16 Index]