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

if (FALSE) { # \dontrun{

library(agridat)
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
libs(lattice)
xyplot(yield ~ log(spacing)|ratef, data=dat,
       auto.key=list(columns=5),
       main="mead.turnip - log(yield) for each density",
       group=ratef)

} # }