Uniformity trial of raddish

Uniformity trial of raddish in four containers.

data("heath.raddish.uniformity")

Format

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

row

row

col

column

block

block

yield

weight per plant

Details

Weight of 399 radish plants grown at 1in x 1in 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.

Source

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

References

None

Examples

# \dontrun{
  require(agridat)
  data(heath.raddish.uniformity)
  dat <- heath.raddish.uniformity
  libs(desplot, dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following object is masked from 'package:nlme':
#> 
#>     collapse
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union
  desplot(dat, yield ~ col*row|block,
          aspect=1,
          main="heath.raddish.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))
#> `summarise()` ungrouping output (override with `.groups` argument)
#> # A tibble: 2 x 2
#>   inner  mean
#>   <lgl> <dbl>
#> 1 FALSE  9.36
#> 2 TRUE   5.80
  # Interior plots are significantly lower yielding
  anova(aov(yield ~ block + inner, dat))
#> Analysis of Variance Table
#> 
#> Response: yield
#>            Df Sum Sq Mean Sq F value    Pr(>F)    
#> block       3   30.4   10.15  0.5055    0.6787    
#> inner       1 1166.3 1166.30 58.0944 1.883e-13 ***
#> Residuals 394 7909.9   20.08                      
#> ---
#> Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
  # lattice::bwplot(yield ~ inner, dat, horiz=0)
  # similar to Heath fig 2-2
  # lattice::histogram( ~ yield|inner, dat, layout=c(1,2), n=20)
# }