agridat (version 1.23)

kreusler.maize: Growth of maize plants in Germany during 1875-1878

Description

Growth of maize plants in Germany during 1875-1878.

Usage

data("kreusler.maize")

Format

A data frame with 165 observations on the following 17 variables.

gen

genotype

year

year

date

calendar date

raindays

number of days of rain per week (zahl der regenstage)

rain

rain amount (mm)

temp

temperature mean (deg C) (temperatur mittel)

parentseed

weight of parent seed (g) (alte korner)

roots

weight of roots (g) (wurzel)

leaves

weight of leaves (g) (blatter)

stem

weight of stem (g) (stengel)

tassel

weight of tassel (g) (blutenstande)

grain

weight of grain (korner)

plantweight

weight of entire plant (ganze pflanze)

plantheight

plant height (cm) (mittlere hohe der pflanzen)

leafcount

number of leaves (anzahl der blatter)

leafarea

leaf area (cm^2) (flachenmaass der blatter)

Details

Experiments were performed at Poppelsdorf, Germany (near Bonn) during the years 1875 to 1878. Observations were collected weekly throughout the growing season.

Five varieties were grown in 1875. Two in 1876, and one in 1877 and 1878.

The plants were selected by eye as representative, with the number of plants chosen decreasing during the growing season. For example, the dry-weight data was based on the following number of plants:

In 1875 the number sampled began at 20 and dropped to 10.

In 1876 the number sampled began at 45 and dropped to 24.

In 1877 the number sampled began at 90 and dropped to 36.

In 1878 the number sampled began at 120 and dropped to 40.

Most of the observations included fresh weight and dry weight of entire plants, along with leaf area, date of inflorescence, fertilization, and kernel development.

The data of Hornberger 71 are the same as Kreusler/Hornberger, but more complete.

The temperature data was originally given in degrees Reaumur in 1875 and 1876, and degrees Celsius in 1877 and 1878. All temperatures in this data are degrees Celsius. Note: deg C = 1.25 deg R. Briggs, Kidd & West (1920) give all temperature in Celsius.

References

Roderick Hunt, G. Clifford Evans. 1980. Classical Data on the Growth of Maize: Curve Fitting With Statistical Analysis. New Phytol, 86, 155-180.

Examples

if (FALSE) {

data(kreusler.maize)
dat <- kreusler.maize
dat$date2 <- as.Date(dat$date,"%d %b %Y")
dat$doy <- as.numeric(strftime(dat$date2, format="%j"))

# Hunt & Evans Fig 2a
libs(lattice)
xyplot(log10(plantweight)~doy|factor(year), data=dat, group=gen,
       type=c('p','smooth'), span=.4, as.table=TRUE,
       xlab="Day of year", main="kreusler.maize - growth of maize",
       auto.key=list(columns=5))

# Hunt & Evans Fig 2b
xyplot(log10(plantweight)~doy|gen, data=dat, group=factor(year),
       type=c('p','smooth'), span=.5, as.table=TRUE,
       xlab="Day of year",
       auto.key=list(columns=4))
# Hunt & Evans Fig 3a
xyplot(log10(leafarea)~doy|factor(year), data=dat, group=gen,
       type=c('p','smooth'), span=.5, as.table=TRUE,
       xlab="Day of year",
       auto.key=list(columns=5))
# Hunt & Evans Fig 3a
xyplot(log10(leafarea)~doy|gen, data=dat, group=factor(year),
       type=c('p','smooth'), span=.5, as.table=TRUE,
       xlab="Day of year",
       auto.key=list(columns=4))

# All traits

xyplot(raindays~doy|factor(year), data=dat, group=gen,
       type='l', auto.key=list(columns=5), as.table=TRUE, layout=c(1,4))
xyplot(rain~doy|factor(year), data=dat, group=gen,
       type='l', auto.key=list(columns=5), as.table=TRUE, layout=c(1,4))
xyplot(temp~doy|factor(year), data=dat, group=gen,
       type='l', auto.key=list(columns=5), as.table=TRUE, layout=c(1,4))
xyplot(parentseed~doy|factor(year), data=dat, group=gen,
       type='l', auto.key=list(columns=5), as.table=TRUE, layout=c(1,4))
xyplot(roots~doy|factor(year), data=dat, group=gen,
       type='l', auto.key=list(columns=5), as.table=TRUE, layout=c(1,4))
xyplot(leaves~doy|factor(year), data=dat, group=gen,
       type='l', auto.key=list(columns=5), as.table=TRUE, layout=c(1,4))
xyplot(stem~doy|factor(year), data=dat, group=gen,
       type='l', auto.key=list(columns=5), as.table=TRUE, layout=c(1,4))
xyplot(grain~doy|factor(year), data=dat, group=gen,
       type='l', auto.key=list(columns=5), as.table=TRUE, layout=c(1,4))
xyplot(plantweight~doy|factor(year), data=dat, group=gen,
       type='l', auto.key=list(columns=5), as.table=TRUE, layout=c(1,4))
xyplot(plantheight~doy|factor(year), data=dat, group=gen,
       type='l', auto.key=list(columns=5), as.table=TRUE, layout=c(1,4))
xyplot(leafcount~doy|factor(year), data=dat, group=gen,
       type='l', auto.key=list(columns=5), as.table=TRUE, layout=c(1,4))
xyplot(leafarea~doy|factor(year), data=dat, group=gen,
       type='l', auto.key=list(columns=5), as.table=TRUE, layout=c(1,4))
xyplot(tassel~doy|factor(year), data=dat, group=gen,
       type='l', auto.key=list(columns=5), as.table=TRUE, layout=c(1,4))
}