Density-Dependent Growth and Life History Evolution of Polycyclic Leaf Pathogens: A Continuous Time Growth Model

A density-dependent growth model of a polycyclic leaf pathogen is analysed. Viability and fecundity of the pathogen are regulated by the current population density. Spores are produced continuously from a sporulating infection until death of the infection, and consequently, all age classes of infections are present at a certain point in time. The leaf area of the host vades with time. Evolution of life history strategies are studied by letting different pathogen genotypes compete with each other. Evolution of life history strategies and evolution of impact of disease are discussed in relation to the ecology of the host-pathogen system. The model is exemplified by Ervsiphe gratninis f. sp. hordei growing on Hordeum vulgare