Anthropomorphic control of crop disease exerts strong selective pressures on plant pathogens. In turn this leads to a risk of breakdown of control, as pathogens become resistant to chemicals or acquire virulence, enabling them to infect resistant hosts. Although there is a significant literature on fungicide resistance (see for e.g. van den Bosch (2008)), much is not yet understood. Almost all models are deterministic, and so cannot properly evaluate the risk of failure associated with any strategy. Typically they also do not consider the socio-economic context in which controls are applied, nor the spatial spread of a pathogen through a population of hosts (that are not necessarily all subject to control). Cultural control also exerts selection pressures, and this is considered only rarely (van den Bosch (2007)). The most obvious example is roguing, in which symptomatic plants are identified and preferentially removed. This clearly selects for strains with more extensive cryptic (i.e. asymptomatic) infection. In developing countries, often the only control that is available, or at least all that is routinely practised, is cultural; the food security implication is clear. This project will tackle these via mathematical modelling, computing, fitting models to data, population biology and genetics.
- van den Bosch F, Jeger MJ, Gilligan CA. (2007) Disease control and its selection for damaging plant virus strains in vegetatively propagated staple food crops; a theoretical assessment. Proc Biol Sci. 274:11-18.
- van den Bosch, F and Gilligan, CA (2008) Models of Fungicide Resistance Dynamics Annu. Rev. Phytopathol. 2008. 46:123–47