Governments across the developing world are scrambling to boost farm imports and restrict exports in an attempt to forestall rising food prices and social unrest.

Saudi Arabia cut import taxes across a range of food products on Tuesday, slashing its wheat tariff from 25 per cent to zero and reducing tariffs on poultry, dairy produce and vegetable oils.

On Monday, India scrapped tariffs on edible oil and maize and banned exports of all rice except the high-value basmati variety, while Vietnam, the world's third biggest rice exporter, said it would cut rice exports by 11 per cent this year.

The moves mark a rapid shift away from protecting farmers, who are generally the beneficiaries of food import tariffs, towards cushioning consumers from food shortages and rising prices.