apples.df: Apples Data

In s20x: Functions for University of Auckland Course STATS 201/208 Data Analysis

Apples Data

Description

These data come from a classic long-term experiment conducted at the East Malling Research Station, Kent, which is the centre for research into apple growing in the U.K. Commercial apple trees consist of two parts grafted together. The lowest part, the rootstock, largely determines the size of the tree, while the upper part (the scion) determines the fruit characteristics. Rootstocks propagated by cuttings (i.e. asexually produced) were once thought to result in smaller trees than those propagated from seeds (i.e. sexually produced). This hypothesis was re-examined in an experiment begun in 1918. Several trees of each type of 16 types of rootstock were planted, all trees having the same scion. Rootstocks I-IX were asexually produced, while X-XVI were sexually produced. In the winter of 1933-4 a number of trees were removed to make room for more, and the data presented here consists of the above-ground weights of 104 trees felled in this period. No trees of types VIII, XI or XIV were felled. The description is adapted from Lee (1994). The data are from Andrews and Herzberg (1985).

Format

The data consist of a data frame with 104 observations on 4 variables.

Rootstock

Factor giving the rootstock type (I, II, III, IV, IX, V, VI, VII, X, XII, XIII, XV, XVI).

Weight

Integer Above-ground weight of tree (pounds, lb).

Weight_kg

Numeric Above-ground weight of tree (kilograms, kg); Weight_kg = Weight * 0.45359237.

Propagated

Factor giving the propagation method (cutting, seed).

References

Andrews, D. F. and Herzberg, A. M. (1985). Data: A Collection of Problems from Many Fields for the Student and Research Worker. New York: Springer.

Lee, A. J. (1994). Data Analysis: An Introduction Based on R. University of Auckland.

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