Yield and number of plants in a sugarbeet fertilizer experiment

Yield and number of plants in a sugarbeet fertilizer experiment.

Usage

data("cochran.beets")

Format

A data frame with 42 observations on the following 4 variables.

fert: fertilizer treatment
block: block
yield: yield, tons/acres
plants: number of plants per plot

Details

Yield (tons/acre) and number of beets per plot. Fertilizer treatments combine superphosphate (P), muriate of potash (K), and sodium nitrate (N).

Source

George Snedecor (1946). Statisitcal Methods, 4th ed. Table 12.13, p. 332.

References

H. Fairfield Smith (1957). Interpretation of Adjusted Treatment Means and Regressions in Analysis of Covariance. Biometrics, 13, 282-308. https://doi.org/10.2307/2527917

Examples

if (FALSE) { # \dontrun{

library(agridat)
data(cochran.beets)
dat = cochran.beets

# P has strong effect
libs(lattice)
xyplot(yield ~ plants|fert, dat, main="cochran.beets") 

} # }