This from The New Scientist…..

An infection is coming, and almost no one has heard about it. This infection isn’t going to give you flu, or TB. In fact, it isn’t interested in you at all. It is after the wheat plants that feed more people than any other single food source on the planet. And because of cutbacks in international research, we aren’t prepared. The famines that were banished by the advent of disease-resistant crops in the Green Revolution of the 1960s could return, Borlaug told New Scientist.

The disease is Ug99, a virulent strain of black stem rust fungus (Puccinia graminis), discovered in Uganda in 1999. Since the Green Revolution, farmers everywhere have grown wheat varieties that resist stem rust, but Ug99 has evolved to take advantage of those varieties, and almost no wheat crops anywhere are resistant to it.

The strain has spread slowly across east Africa, but in January this year spores blew across to Yemen, and north into Sudan (see Map). Scientists who have tracked similar airborne spores in this part of the world say it will now blow into Egypt, Turkey and the Middle East, and on to India, lands where a billion people depend on wheat.

Of course to make matters worse, wheat stocks are low….

The threat couldn’t have come at a worse time. Consumption has outstripped production in six of the last seven years, and stocks are at their lowest since 1972. Wheat prices jumped 14 per cent last year.

The whole article is well worth reading.