Stability Coefficients
See Also
To assess new genotypes of plants, trials are often carried out in a range of environments. Yields and other measurements will then be made, and analyses carried out (e.g. using REML) to see how well the genotypes perform. These analyses allow you to determine which genotypes are best overall, or at a specific site. However, they do not consider how reliable, or stable, their yields may be overall. This menu allows you to calculate several stability coefficients to assess this.

Available Data

This lists data structures appropriate to the current input field. It lists variates for use in specifying the y-variate, and factors for the genotypes and environments. Double-click on a name to copy it to the current input field; alternatively, you can type the name directly into the input field.

Y-variate

Specifies a variate for the data to be analysed.

Genotypes

A factor specifying the genotypes.

Environments

A factor specifying the environments.

Method

Selects the type of method used to calculate the coefficients. The ranks setting
Superioritycalculates the cultivar-superiority measure of Lin & Binns (1988). For each genotype, this is the sum of the squares of the differences between its mean in each environment and the mean of the best genotype there, divided by twice the number of environments.
Ranksgives the mean and variance of the ranks of each genotype across the environments where it occurs, as well as the rank-difference coefficient of Nassar & Huehn (1987). For each genotype, this is the sum of the absolute differences between its ranks in all the pairs of environments where it occurs.

Action Buttons

RunRun the analysis.
CancelClose the menu without further changes.
OptionsOpens a dialog where additional options and settings can be specified.
DefaultsSet the menu settings back to the default settings. Clicking the right mouse on this button produces a shortcut menu where you can choose to set the menu using the currently stored defaults or the GenStat default settings.
StoreOpens a dialog to specify names of structures to store the results from the analysis. The names to save the structures should be supplied before running the analysis.

See Also