COMMENT ON A RECENTLY PROPOSED STABILITY PARAMETER

The actual yields from multisite variety trials are usually analysed a s a two-way table (rows = varieties, columns = sites) of mean yields. Recently, Yen and Hamblin (1994) proposed the variance of relative yie ld across sites as a useful stability parameter. In this paper, it is shown that this stability parameter measures the variability of the de viations from a reference line with the slope equal to variety mean/to tal mean.