A Fungus Among Us

For the apocalyptically-minded, another sign the end is near.  According to an article in the New Scientist, forget about cropland being diverted to feed SUVs (anyone want to talk about the morality of that?) Forget about droughts and export bans and food riots, forget about the new middle classes in China and India driving demand.  What we should be worrying about is fungus, black stem wheat rust, Puccinia graminis:

It can reduce a field of ripening grain to a dead, tangled mass, and vast outbreaks regularly used to rip through wheat regions. The last to hit the North American breadbasket, in 1954, wiped out 40 per cent of the crop. In the cold war both the US and the Soviet Union stockpiled stem rust spores as a biological weapon

Wheat rust has been around since humans decided brioche was preferable to grubs as the breakfast food of choice. The problem now: a new variant strain of wheat rust called Ug99 has emerged.  The strain was first identified in Uganda in 1999, and has spread into east Africa.  Fungicides are effective against rust, but are generally unavailable to poor farmers in the developing world, and are even limited in the first world.  Resistant varieties of wheat are being developed, but it may take as long as eight years to be produced in sufficient quantities for seed.  Ironically, agricultural techniques and high yield seed lines developed during the Green Revolution of the 1960s are contributing to the problem: wheat is grown far more densely than in the past, so fungus has a chance to get a foothold in damp, warm conditions.  The potential for an exacerbating food shortage is alarming, especially if it affects large wheat producing countries or places where life depends on a good crop.

The great fear, according to the article, is that wheat rust spores will be blown into central Asia, where wheat varietals are generally not resistant to the disease, and where its alternate host, the barberry (Berberis vulgaris) is native. This last is important, because it is on B. vulgaris and related plants that wheat rust swaps genetic information, producing new variants.  B. vulgaris, it should be added, is widely naturalized in North America.  A crop scientist (unintentionally engaging in humour) comments: “As if it wasn’t challenging enough breeding varieties that resist this thing. All I know is that what blows into Iran will not be the same as what blows out.”  True of many things, not just wheat rust.

Except the wheat rust has in fact been detected in Iran:

A new and virulent wheat fungus, previously found in East Africa and Yemen, has moved to major wheat growing areas in Iran, FAO reported today. The fungus is capable of wreaking havoc to wheat production by destroying entire fields.

Countries east of Iran, like Afghanistan, India, Pakistan, Turkmenistan, Uzbekistan and Kazakhstan, all major wheat producers, are most threatened by the fungus and should be on high alert, FAO said.

It is estimated that as much as 80 percent of all wheat varieties planted in Asia and Africa are susceptible to the wheat stem rust (Puccinia graminis). The spores of wheat rust are mostly carried by wind over long distances and across continents.

“The detection of the wheat rust fungus in Iran is very worrisome,” said Shivaji Pandey, Director of FAO’s Plant Production and Protection Division.

“The fungus is spreading rapidly and could seriously lower wheat production in countries at direct risk. Affected countries and the international community have to ensure that the spread of the disease gets under control in order to reduce the risk to countries that are already hit by high food prices.”

A glass for Robigus, please

I was only being half-facetious in referring to the apocalypse.  The links between wheat rust and religion go back to the dawn of agriculture, when crop disease spelled starvation and pestilence and wheat mysteriously and suddenly withering in the field was a sure indication of divine wrath. Robigus (meaning “mildew” or “wheat rust”) was a Roman god whose propitiation — by tipping a cup of red wine to ground, perhaps, in a conceit of colour or affinity — was necessary to prevent the blight. And long before Mars became a god of war, he concerned himself with fertility and crops, fields and boundary lines. “Neve lue rue, Marmar, sins incorrere in pleores,” cried the ancient Romans, when Rome was a collection of mudbrick huts encircled by a wooden palisade.  Let not blight or ruin attack, O Mars!  It is not a coincidence that March, the time of wheat sowing, was named for Mars. Or think of the dreams of Pharaoh, as interpreted by that likely mensch Joseph: seven heads of thin scorched wheat swallowing up seven full heads.

Maybe a sacrifice to Mars or Robigus might be in order.  Or maybe we should heed Joseph’s advice to Pharaoh, and stockpile for seven years.