ABSTRACT
The incidence of fungal plant pathogens on grasses has been shown to increase with increasing latitude (Clay, 1997). It is assumed that this is related to the increased stresses imposed on plants by adverse climatic conditions, which make them more susceptible to pathogen attack. Much of the data underpinning this statement comes from agroecosystems, however, and Clay (1997) states that the number of pathogens per host plant is significantly lower in noncrop plant species than in crop species (Fig. 3.33).
