Uniformity trial of radish

Uniformity trial of radish in four containers.

Usage

data("heath.radish.uniformity")

Format

A data frame with 400 observations on the following 4 variables.

row

row

col

column

block

block

yield

weight per plant, grams

Details

Weight of 399 radish plants grown at 1 inch x 1 inch spacing in four plastic basins. Seed wetted 1968-02-15, planted 1968-02-17, harvested 1968-03-26.

Heath said, Most of the large plants were round the edges...one important source of variation might have been competition for light.

Location if the experiment is unknown, but Heath was Professor of Horticulture at the University of Reading, United Kingdom, so it is likely the experiment was conducted in the U.K.

Source

O.V.S. Heath (1970). Investigation by Experiment. Table 1, p 24-25. https://archive.org/details/investigationbye0000heat

References

None

Examples

if (FALSE) { # \dontrun{
  require(agridat)
  data(heath.radish.uniformity)
  dat <- heath.radish.uniformity
  libs(desplot, dplyr)
  desplot(dat, yield ~ col*row|block,
          aspect=1,
          main="heath.radish.uniformity")

  # Indicator for border/interior plants
  dat <- mutate(dat,
                inner = row > 1 & row < 10 & col >  1 & col < 10)
  # Heath has 5.80 and 9.63 (we assume this is a typo of 9.36)
  dat <- group_by(dat, inner)
  summarize(dat, mean=mean(yield, na.rm=TRUE))
  # Interior plots are significantly lower yielding
  anova(aov(yield ~ block + inner, dat))
  # lattice::bwplot(yield ~ inner, dat, horiz=0)
  # similar to Heath fig 2-2
  # lattice::histogram( ~ yield|inner, dat, layout=c(1,2), n=20)
} # }