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.
beetsThe format is: chr "beets"
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
+-----------|-----------|-----------+
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/
data(beets)
beets$bh <- with(beets, interaction(block, harvest))
summary(aov(yield ~ block + sow + harvest + Error(bh), beets))
summary(aov(sugpct ~ block + sow + harvest + Error(bh), beets))
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