Of the various challenges to food security, the threat of fungal (and oomycete) infection of our calorie and commodity
crops outstrips that posed by bacterial and viral diseases combined (Fisher et al., 2012 Nature; Fones et al., 2020 Nature
Food). We face a future blighted by known adversaries, by new variants of old foes and by new diseases. Modern
agricultural intensification practices have heightened this challenge – the planting of vast swathes of genetically uniform
crops, guarded by one or two inbred resistance (R) genes, and use of single target site antifungals has hastened
emergence of new virulent and fungicide-resistant strains (Fisher et al., 2018 Science; Fisher et al., 2022 Nature
Microbiology), and has enhanced the risk of mycotoxin contamination (Johns et al., 2022 in press). Climate change
compounds the saga, as we see altered disease demographics – pathogens are moving poleward in a warming world
(Bebber et al., 2013 Nature Climate Change; Chaloner et al., 2021 Nature Climate Change).
This talk will highlight some current notable and persistent fungal diseases. It will consider the evolutionary drivers which
underpin emergence of new diseases and manmade “accelerators” of spread. I will set these points in the context of a
series of different disease models, initially with statistical correlative models, and thence with more recent mechanistic
models – parametrised by data collected from pathogen, host, climate and with a temporal axis (Fones et al., 2020). Such
models have enabled us to look across biological scales, that is from the global level to crop to host-pathogens per se, in
our development of predictive movement models. In essence, the presentation will cover the global distributions of crop
pathogens (Bebber et al., 2013), their predicted movement (Bebber et al., 2014 New Phytologist), crop disease saturation
(Bebber et al., 2014 Global Ecology and Biogeography) and thence present our more recent work, which aligns ecology
with plant disease biology to (i) evaluate the risk of specialist and generalist pathogens (Chaloner et al., 2020 Nature
Communications) and, in particular, (ii) the demonstration that crop yields will increase at higher latitudes but likely
decline in the tropics (recent versus 2027), but that such yield gains will be tempered by a greater burden of disease and
by unfamiliar pathogens. Moreover, regions such as US, Europe and China will experience major changes in pathogens
assemblages (Chaloner et al., 2021).
A recording of this presentation can be found on our youtube channel.