agridat (version 1.23)

williams.cotton.uniformity: Uniformity trial of cotton

Description

Uniformity trial of cotton at Narrabri, New South Wales, 1984.

Format

A data frame with 288 observations on the following 3 variables.

row

row

col

column

yield

lint yield, kg/ha divided by 10

Details

Cotton uniformity trial grown at Narrabri, New South Wales, 1984-1985. Plots were 12m long, 1m apart, 12 rows by 24 columns, with an irrigation furrow between columns.

Field width: 24 plots * 1 m = 24 m

Field length: 12 plots * 12 m = 144 m

Examples

if (FALSE) {

library(agridat)
data(williams.cotton.uniformity)
dat <- williams.cotton.uniformity

libs(desplot)
desplot(dat, yield ~ col*row,
        aspect=144/24, # true aspect
        main="williams.cotton.uniformity")


# Smoothed contour/persp plot like Williams 1988 Fig 1a, 2a
dat$fit <- fitted(loess(yield~col*row, dat, span=.5))
libs("lattice")
contourplot(fit~col*row, data=dat,
            aspect=144/24,
            region=TRUE, cuts=6, col.regions=RedGrayBlue,
            main="williams.cotton.uniformity")
# wireframe(fit~col*row, data=dat, zlim=c(100, 250),
#           main="williams.cotton.uniformity")

# Williams table 1
anova(aov(yield ~ factor(row) + factor(col), dat))
}