agridat (version 1.16)

jansen.apple: Infestation of apple shoots by apple canker.

Description

Infestation of apple shoots by apple canker.

Usage

data("jansen.apple")

Format

A data frame with 36 observations on the following 5 variables.

inoculum

inoculum level

gen

genotype/variety

block

block

y

number of inoculations developing canker

n

number of inoculations

Details

Shoots of apple trees were infected with fungus Nectria galligena, which may cause apple canker.

The incoulum density treatment had 3 levels, measured in macroconidia per ml.

There were 4 blocks.

References

None.

Examples

# NOT RUN {
data(jansen.apple)
dat <- jansen.apple

require(lattice)
xyplot(inoculum ~ y/n|gen, data=dat, group=block,
       layout=c(3,1),
       main="jansen.apple",
       xlab="Proportion infected per block/inoculum",
       ylab="Inoculum level")

# }
# NOT RUN {
  require(lme4)
  # Tentative model.  Needs improvement.
  m1 <- glmer(cbind(y,n-y) ~ gen + factor(inoculum) + (1|block),
              data=dat, family=binomial)
  summary(m1)
# }
# NOT RUN {
# }