Ertragsstabilität und Qualität von Weizensortenmischungen im Ökologischen Anbau

Summary

Disease development, yield and baking quality were assessed on the winter wheat cultivars Arina and Capo and their 1:1 mixture in a total of 12 sites on-farm in 2002/2003. Due to a severe drought disease severities were very low and probably had little effect on the plants. The more drought tolerant variety Capo over-yielded in mixtures on average by 21% while Arina yielded in mixtures as expected. Protein and gluten contents and baking volume in pure stands of Arina were usually higher than for Capo. Both varieties changed their quality parameters in mixtures. However, the parameters of the mixtures were not equal to the mean of the pure stands indicating some unknown interactions. The quality parameters of each variety or mixture were compared to the mean of all treatments in a given site allowing for regression analysis across sites. Capo was least able to improve its quality in reaction to improved site potential (expressed as mean baking volume) (slope: 0.64) while the mixtures reacted strongest (slope: 1.47). This indicates that mixtures might be better able to profit from good growing conditions than pure stands.