agridat (version 1.23)

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.

Used with permission of J. Jansen. Electronic version supplied by Miroslav Zoric.

References

None.

Examples

if (FALSE) {

library(agridat)
data(jansen.apple)
dat <- jansen.apple

libs(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")

## libs(lme4)
## # Tentative model.  Needs improvement.
## m1 <- glmer(cbind(y,n-y) ~ gen + factor(inoculum) + (1|block),
##             data=dat, family=binomial)
## summary(m1)

}