The dependence of DUS (distinctness, uniformity and stability) decisions concerning white mustard and oilseed rape varieties on the number of measurements

Abstract

Summary An analysis is made of the possibility of reducing numbers of measurements in DUS (distinctness, uniformity and stability) trials on varieties of white mustard and oilseed rape, based on the results of DUS trials performed in the years 2005–2009 by the Research Centre for Cultivar Testing. It is shown that, when decisions are taken after three years of testing, it is possible to decrease the number of measurements by 50%, with the decisions practically unchanged for both considered species. For so-called early decisions (after two years of testing) the distinctness decisions are again practically the same for full and reduced data, although the decisions concerning uniformity differ significantly. This means that the number of measurements can be reduced only in cases where DUS testing is continued for three years.