U SE OF M ULTILINE C ULTIVARS AND C ULTIVAR M IXTURES FOR D ISEASE M ANAGEMENT

The usefulness of mixtures (multiline cultivars and cultivar mixtures) for disease management has been well demonstrated for rusts and powdery mildews of small grain crops. Such mixtures are more useful under some epidemiological conditions than under others, and experimental methodology, especially problems of scale, may be crucial in evaluating the potential efficacy of mixtures on disease. There are now examples of mixtures providing both low and high degrees of disease control for a wide range of pathosystems, including crops with large plants, and pathogens that demonstrate low host specificity, or are splash dispersed, soilborne, or insect vectored. Though most analyses of pathogen evolution in mixtures…