The role of rain in dispersal of pathogen inoculum

The importance of rain in the dispersal of micro-organisms was first demon­ strated in the 1880s, in the classic studies of Pierre Miquel (Figure 1) on the microflora of the Pare Montsouris in Paris. Collected rainwater contained large numbers of fungal spores and bacteria and numbers of airborne spores and bacteria decreased while rain was falling (61). By contrast, numbers of airborne micro-organisms collected by the suction sampler frequently in­ creased during intervals between rain showers