Towards a realistic model of long-range plant pathogen transport by wind.*

In recent work (Phys. Rev. E 96, 022220), a model of continental-scale plant pathogen spread by wind was proposed.  The model was designed to study the competition between the short-range hopping mechanism of transport due to the near-Earth turbulence, and the mechanism provided by the laminar advective currents that lie above the planetary boundary layer.  The main finding was that the latter is often the dominant mechanism of propagation of invasion fronts.  However, the basic model lacks sufficient biological realism, and over-predicts the speed of invasions.  In the present work, we further develop the basic model in several directions.  First, we add the effect of spore death due to UV exposure – a crucial factor known to phytopathologists.  Second, in addition to mobile spores we now include immobile fungi, as well as the role of latent time required for new fungus to start producing spores.  Our study shows that these additions allow for slowing down of the invasion speed closer to realistic values.