Notes on the Variance of Relative Yield as a Measure of Stability

The actual yields from multilocation variety trials are commonly analysed as a two-way table (rows = varieties, columns = locations) of mean yields. In this paper, relationships between the recently proposed new stability parameter 'variance of relative yield' and the two stability parameters of the 'classical' joint regression approach in stability analysis, are investigated. The variance of relative yield as a measure of stability exhibits an undesirable dependence on the mean yield of the respective variety. Generalizations and improvements of some recent results and conclusions of Piepho (1994) are discussed.