As Ug99, the deadly stem rust-causing fungus blighting African wheat, marches eastward, scientists across the globe are scrambling for ways to outsmart it.
First discovered in Uganda 12 years ago, Ug99 has since snowballed, through Kenya, Ethiopia, Sudan and, now, Yemen.
"I look at Yemen as the gateway into the Middle East, into Asia," says David Hodson of the Food and Agriculture Organization.
Indeed, fears are rife that Ug99 is headed for the Punjab, South Asia's most important breadbasket, which feeds hundreds of millions.
Researchers are trying to develop wheat strains that contain insurmountable genetic barriers for the fungus. But the fungus is mutating, enabling it to overcome the barriers put up by resistant genes in today's crops. Four variants of Ug99 are able to "knock out" such resistance genes.
In Njoro, Kenya, wheat breeders are working on promising wheat varieties in the hope that one of them can outwit Ug99. And a two-year project to sequence the fungus genome hopes to identify the specific wheat-destroying genes so that new breeds of wheat can be screened for Ug99 resistance.
More far-fetched dreams include the insertion of genes that can scramble Ug99 spores' "topographical sense" so that they cannot burrow into wheat.