Host genotype diversity and its effects on pathogen populations

Host genotype diversity = “host heterogeneity”

Technically…

Basic idea: if monoculture maximizes selection for new virulences, take a step back

Host genotype diversity

“Mid-component”: the mean of the mixture’s component cultivars when they are grown as pure stands

Mechanisms of disease reduction in small-grain blends

Club wheat mixture: components can be distinguished by head color

From data in Finckh & Mundt, 1992, Stripe rust, yield, and plant competition in wheat cultivar mixtures, Phytopathology 82:905-913

Characteristics that predict whether blends will reduce disease (Garrett & Mundt, 1999)

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Spatial scale is predicted by theory to be important to blend effectiveness

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