Alfalfa: Split-Plot Experiment on Varieties of Alfalfa
Description
The Alfalfa data frame has 72 rows and 4 columns.
Arguments
source
Pinheiro, J. C. and Bates, D. M. (2000), Mixed-Effects Models in S
and S-PLUS, Springer, New York. (Appendix A.1)
Snedecor, G. W. and Cochran, W. G. (1980), Statistical Methods (7th
ed), Iowa State University Press, Ames, IA
Details
These data are described in Snedecor and Cochran (1980) as
an example of a split-plot design. The treatment structure used in the
experiment was a 3$x$4 full factorial, with three varieties of
alfalfa and four dates of third cutting in 1943. The experimental
units were arranged into six blocks, each subdivided into four plots.
The varieties of alfalfa (Cossac, Ladak, and
Ranger) were assigned randomly to the blocks and the dates of
third cutting (None, S1---September 1,
S20---September 20, and O7---October 7) were randomly
assigned to the plots. All four dates were used on each block.