beets data

Yield and sugar percentage in sugar beets from a split plot experiment. Data is obtained from a split plot experiment. There are 3 blocks and in each of these the harvest time defines the "whole plot" and the sowing time defines the "split plot". Each plot was 25 square meters and the yield is recorded in kg. See 'details' for the experimental layout.

beets

Format

The format is: chr "beets"

Details

  
Experimental plan
Sowing times            1        4. april
                        2       12. april
                        3       21. april
                        4       29. april
                        5       18. may
Harvest times           1        2. october
                        2       21. october
Plot allocation:
               Block 1     Block 2     Block 3
            +-----------|-----------|-----------+
      Plot  | 1 1 1 1 1 | 2 2 2 2 2 | 1 1 1 1 1 | Harvest time
       1-15 | 3 4 5 2 1 | 3 2 4 5 1 | 5 2 3 4 1 | Sowing time
            |-----------|-----------|-----------|
      Plot  | 2 2 2 2 2 | 1 1 1 1 1 | 2 2 2 2 2 | Harvest time
      16-30 | 2 1 5 4 3 | 4 1 3 2 5 | 1 4 3 2 5 | Sowing time
            +-----------|-----------|-----------+  

References

Ulrich Halekoh, Søren Højsgaard (2014)., A Kenward-Roger Approximation and Parametric Bootstrap Methods for Tests in Linear Mixed Models - The R Package pbkrtest., Journal of Statistical Software, 58(10), 1-30., https://www.jstatsoft.org/v59/i09/

Examples

data(beets)

beets$bh <- with(beets, interaction(block, harvest))
summary(aov(yield ~ block + sow + harvest + Error(bh), beets))
#> 
#> Error: bh
#>           Df Sum Sq Mean Sq  F value   Pr(>F)    
#> block      2   11.3     5.7    4.018 0.199292    
#> harvest    1 1725.2  1725.2 1225.000 0.000815 ***
#> Residuals  2    2.8     1.4                      
#> ---
#> Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
#> 
#> Error: Within
#>           Df Sum Sq Mean Sq F value   Pr(>F)    
#> sow        4   8369  2092.3   119.7 1.13e-13 ***
#> Residuals 20    349    17.5                     
#> ---
#> Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
summary(aov(sugpct ~ block + sow + harvest + Error(bh), beets))
#> 
#> Error: bh
#>           Df  Sum Sq Mean Sq F value Pr(>F)  
#> block      2 0.03267 0.01633   2.579 0.2794  
#> harvest    1 0.09633 0.09633  15.211 0.0599 .
#> Residuals  2 0.01267 0.00633                 
#> ---
#> Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
#> 
#> Error: Within
#>           Df Sum Sq Mean Sq F value   Pr(>F)    
#> sow        4   1.01  0.2525     101 5.74e-13 ***
#> Residuals 20   0.05  0.0025                     
#> ---
#> Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1