[Stori]

The mass diversion of the North American grain harvest into ethanol plants for fuel is reaching its political and moral limits.

The UN says it takes 232kg of corn to fill a 50-litre car tank with ethanol. That is enough to feed a child for a year. Last week, the UN predicted "massacres" unless the biofuel policy is halted.

World grain stocks have fallen to a quarter-century low of 5m tonnes, rations for eight to 12 weeks. America - the world's food superpower - will divert 18pc of its grain output for ethanol this year, chiefly to break dependency on oil imports. It has a 45pc biofuel target for corn by 2015.

Argentina, Canada, and Eastern Europe are joining the race

The world food situation is very serious: we have seen riots in Egypt, Cameroon, Haiti and Burkina Faso," said Mr Diouf. "There is a risk that this unrest will spread in countries where 50pc to 60pc of income goes to food," he said.

Haiti's government fell over the weekend following rice and bean riots. Five died.

The global food bill has risen 57pc in the last year. Soaring freight rates make it worse. The cost of food "on the table" has jumped by 74pc in poor countries that rely on imports, according to the FAO.

Roughly 100m people are tipping over the survival line. The import ratio for grains is: Eritrea (88pc), Sierra Leone (85pc), Niger (81pc), Liberia (75pc), Botswana (72pc), Haiti (67pc), and Bangladesh (65pc).