agridat (version 1.5)

williams.cotton: Lint yield from a cotton uniformity trial

Description

Lint yield from a cotton uniformity trial

Usage

data(williams.cotton)

source

Williams, ER and Luckett, DJ. 1988. The use of uniformity data in the design and analysis of cotton and barley variety trials. Australian Journal of Agricultural Research, 39, 339-350.

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.

Examples

dat <- williams.cotton

require("lattice")
asp = (12*12)/(24*1) # true aspect
desplot(yield ~ col*row, dat, aspect=asp)

# Smoothed contour/persp plot like Williams 1988 Fig 1a, 2a
dat$fit <- fitted(loess(yield~col*row, dat, span=.5))
contourplot(fit~col*row, data=dat, cuts=6)
wireframe(fit~col*row, data=dat, zlim=c(100, 250))

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