fineroot {GLMsData}

The root length density of apple trees

Description

The root length density of apple trees

Usage

data(fineroot)

Format

A data frame with 511 observations on the following 5 variables.

Plant

the plant number; a numeric vector

Rstock

the root stock; a factor with levels Mark, MM106 or M26

Spacing

the plant spacing; a factor with levels 5x3 or 4x2 (measured in metres)

Zone

the zone relative to the plant from which the soil core is taken; a factor with levels Inner or Outer

RLD

the root length density in centimetres per cubic centimetre; a numeric vector

Details

The data concern the underground root system of eight apple trees. Three different root stocks and two plant spacings are used; the root length density (the density of the fine roots) is measured in one of the two zones.

The design is not full factorial: plants 1 and 2 are for Mark rootstock at 5x3 spacing; plants 3 and 4 are for Mark rootstock at 4x2 spacing; plants 5 and 6 are for MM106 rootstock at 5x3 spacing; plants 7 and 8 are for M26 rootstock at 4x2 spacing.

Source

Personal communication from Nihal de Silva.

References

H. N. de Silva, A. J. Hall, D. S. Tustin and P. W. Gandar (1999) Analysis of distribution of root length density of apple trees on different dwarfing rootstocks. Annals of Botany, 83, 335–345.

P. K. Dunn and G. K. Smyth (2005) Series evaluation of Tweedie exponential dispersion model densities. Statistics and Computing, 15(4), 267–280.

Examples

data(fineroot)
summary(fineroot)