Powdery mildew intensity, grain yield and its stability of the mixtures of spring wheat cultivars

摘要

Field trials with the mixtures of spring wheat cultivars were conducted in three locations in 1994 -- 1996. Five commercial cultivars with different powdery mildew resistance genes were tested in pure stands and in all possible two- and three-component mixtures in four replicates. The objects were assessed for disease intensity, grain yield and its stability. The infection intensity of wheat powdery mildew (Erysiphe graminis f. sp. tritici) depended on the composition of the mixture. In.some mixtures the disease intensity was reduced by 83 -- 94% as compared to the infection occurring in the component cultivars grown in pure stands. In the three-component mixtures the disease was reduced slightly more than in the two-component ones. In most cases the yield of cultivar mixtures was by 0.2 -- 18% higher and more stable than that of the mean of their components grown in pure stands. Some of these mixtures yielded significantly better than the best component.