Aggressive strains of the pathogenic fungus, Puccinia graminis f.sp. tritici, causing the devastating crop disease wheat stem rust, have been detected in East Africa and the Middle East.These emerging and evolving strains can be wind-dispersed over large regions and even entire continents, posing a threat to global wheat production. Disease management has been restricted
by a lack of information about key pathways and typical frequencies of long-distance dispersal events. We obtain, for the first time, quantitative estimates of spore transmission frequencies and amounts between all wheat producing countries in Southern/East Africa, the Middle East, and Central/South Asia. Results of long-term Lagrangian particle dispersal simulations over dynamically changing host and environmental landscapes allow us to distinguish wheat areas at risk in particular times of the year. We find zones of high airborne connectivity that correspond geographically with previously postulated epidemiological zones of wheat stem rust. Our work quantifies the risk of LDD of the Ug99 race group from Africa to the wheat producing areas in India and Pakistan. Country-specific dispersal patterns are now available to support more effective, targeted surveillance and control measures.
Identifying airborne migration routes of fungal pathogens to safeguard global food supply
