BANGKOK (AFP) ¡ª Myanmar is struggling to feed its people in the aftermath of Cyclone Nargis -- in part because the regime has been forcing some farmers to stop growing rice in a plan to produce biofuel instead.

In 2005 the military government's leader Than Shwe ordered a national drive to plant jatropha, a poisonous nut he hoped would be the cornerstone of a state industry that would capitalise on growing world demand for biofuels.

Taking a page from the textbook of planned centralised economies, he issued a quota for jatropha production for every township in the country -- even in cities, where people were forced to grow it in their yards and along roads.

"It was the national duty," said Sai Khur Hseng, a Myanmar exile who has extensively studied the government's biofuel programme. "Everybody had to plant it."

A flowering bush which produces a nut that is poisonous to humans and animals but high in oil, jatropha is usually planted in arid regions where little else can survive.

But in fertile regions such as the southern Irrawaddy delta, where the cyclone hit, Than Shwe's edict meant that fields producing rice and other foods were torn up, said Monique Skidmore of the Australian National University said.

"This has meant that people have either had to not plant paddy or pull up paddy" to grow the crop, she said.

In some cases, the military actually confiscated land from farmers to grow the nuts, said Dave Mathieson, a researcher with Human Rights Watch.

"It's just absurd," Mathieson said.

"In the rural areas, it's the military that's responsible for meeting the quota. So they've just been seizing land and ripping out food crops to grow jatropha."

But after the crop started to grow, farmers discovered a bitter truth -- they could not sell it.

The government has not bought the jatropha nuts because it hadn't set up any facilities to process biofuel, Skidmore said.

"They don't have even the sort of tanks and trucks and warehousing and distribution to handle" biofuel production, she said.

The fiasco has now turned to tragedy for the people of Myanmar, which was once one of the world's top exporters of rice.

Decades of central economic planning along with other autocratic policies have made it difficult for the regime to feed its people.

Even before the cyclone, the UN's World Food Programme estimated that 10 percent of Myanmar's more than 50 million people did not have enough to eat.

The cyclone, which left at least 62,000 people dead or missing, has now further imperilled the nation's food supply because so much of the fertile delta has been turned into swampland by the storm.

The United Nations has warned that the country, where up to two million victims of the cyclone face immediate needs for food, water and shelter, could face food shortages for years to come.

"This is the rice basket of the country, and clearly damage has been done to the paddy fields," said Richard Horsey, of the UN's emergency relief arm.

"Some ... have been inundated with salt water, others flooded and stocks of seed for planting destroyed. So it will be an issue, and there are agricultural assessments under way to determine the full extent of the problem."