Experts in Europe and Africa are racing to develop resistant grain varieties as university researchers predict the likely spread across continents of the air-borne spores of the fungus

Scientists are warning that wheat is facing a serious threat from a fungal disease that could wipe out the world’s crop if not quickly contained. Wheat rust, a devastating disease known as the “polio of agriculture”, has spread from Africa to South and Central Asia, the Middle East and Europe, with calamitous losses for the world’s second most important grain crop, after rice. There is mounting concern at the dangers posed to global food security.