At Wired, an alarming piece on UG99, a new variant of stem rust that threatens the global wheat crop and therefore the food supply of a few billion people:
The enemy is Ug99, a fungus that causes stem rust, a calamitous disease of wheat. Its spores alight on a wheat leaf, then work their way into the flesh of the plant and hijack its metabolism, siphoning off nutrients that would otherwise fatten the grains. The pathogen makes its presence known to humans through crimson pustules on the plant’s stems and leaves. When those pustules burst, millions of spores flare out in search of fresh hosts. The ravaged plant then withers and dies, its grains shriveled into useless pebbles. . . .Have a nice day.
The pathogen has already been detected in Iran and may now be headed for South Asia’s most important breadbasket, the Punjab, which nourishes hundreds of millions of Indians and Pakistanis. What’s more, Ug99 could easily make the transoceanic leap to the United States. All it would take is for a single spore, barely bigger than a red blood cell, to latch onto the shirt of an oblivious traveler. The toll from that would be ruinous; the US Department of Agriculture estimates that more than 40 million acres of wheat would be at serious risk if Ug99 came to these shores, where the grain is the third most valuable crop, trailing only corn and soybeans. The economic loss might easily exceed $10 billion; a simple loaf of bread could become a luxury. “If this stuff gets into the Western Hemisphere,” Steffenson says, “God help us.”