agridat (version 1.23)

cochran.beets: Yield and number of plants in a sugarbeet fertilizer experiment

Description

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).

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) {

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

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

}