MANKHOKWE, Malawi (AP) - Dona Kijani dives into a crocodile-infested river for water lilies, gambling with death to pull up tubers that are barely edible and give her children diarrhea. She says it is her only source of food.

For Kijani and many of her neighbors in the dirt-poor southern tip of Malawi, water lilies have become a staple part of the diet as drought withers corn crops, worsening a malnutrition problem aggravated by poverty, corruption and AIDS.

”I have nothing else to give to my children,“ the widowed mother of three young children said with a grimace, holding out some of the small, bitter-tasting, gnarled roots.

With the food crisis worsening, President Bingu wa Mutharika declared all of the southern African nation a ”disaster area“ Saturday and appealed for international help. He warned that 5 million people, almost half the population, are threatened with hunger.

Opposition politicians and civic leaders complained that the declaration should have come much sooner. But the president has been snarled in an impeachment battle with parliament leaders he has accused of hindering his campaign to clamp down corruption.

Mutharika said the government would spend $50 million to import 330,000 tons of corn from South Africa but that Malawi needs an additional 158,000 tons to help feed people until the next harvest.

Kijani is among those needing help.

”I'm desperate to be registered to receive food aid,“ she said recently while standing with thousands of others in front of a dusty warehouse hoping in vain to receive the 110-pound monthly corn ration.

The scene at the Mankhokwe distribution center was a microcosm of what is happening across all of southern Africa, where an estimated 12 million people will need food aid in the coming months because of drought, mismanagement and disease.

Malawi, already one of the world's poorest nations, is the worst affected in the region.

The long, landlocked country is no stranger to hunger, but aid groups fear the current food crisis will be the worst in a decade. Drought has been a blow, and with more than 14 percent of Malawians infected with the AIDS virus, many farmers are too sick to work.

So far, donors have provided only $28 million for Malawi relief, far below the $88 million sought by the United Nations. Appeals for seed and fertilizer have gone mostly unheeded. Even once funds are promised, it takes four months for the aid to reach hungry mouths.

Most of the worst-hit villages in the south lie in a fertile river valley fed with water from Lake Malawi. But in a country where most peasants cannot afford even spades and wheelbarrows, farmers have no means to transport the water to their fields.

The government sees irrigation as the answer to the vicious cycle of drought and despair.

”We are fed up of rain-fed harvests. They are not predictable. We want to use irrigation to wipe out this hunger problem because it is perennial. We see it every year,“ Agriculture Minister Uladi B. Mussa told foreign journalists.

There are some glimmers of hope. In the village of Chitsukwa, in the southern province of Nsanje, the European Union has helped finance projects using basic treadle pumps operated by one or two people to draw water from a nearby canal.

At the start of this year, only one person in the village was irrigating just a half acre, but now 106 farmers - 86 of them women - are irrigating 44 acres. The hope is to plant three crops a year.

The Irish charity GOAL spent $50,000 on seeds, tools and training for two irrigation projects in the area. Green stands of corn now shoot up in fields that stand out starkly in the barren countryside.

”I'm really happy we can irrigate our crops. It's good that I can finally produce my own food rather than being dependent on someone else,“ said Meria Gama, flashing a toothless smile as her two grandchildren played happily in the muddy ground by her feet.

But the overall picture in the former British colony is relentlessly grim. Even in ”normal“ years, more than one in ten mothers dies in child birth - and there is a similar toll among infants. Nearly one in five children doesn't survive to age 5.