Yield of spring barley mixtures as a function of varietal and

To design good variety mixtures it is important to understand the influence of varietal and environmental characteristics on mixing effect, e.g. what characteristics are more beneficial when all mixed varieties express it highly and what characteristics are more beneficial when the mixed varieties express it to varying extent. However, as it is generally impossible to manage more than a few experimental combinations in each field trial, information on general relationships and factors of importance for the successful design of variety mixtures may be overlooked. Using meta-regression (e.g. Houwelingen et al. 2002), numerous results of such trials can be combined, and the influence of varietal and environmental factors on mixing effect can be elucidated. Here, two specific hypotheses were investigated: