As the world grapples with high rice prices, scientists are racing to find new varieties that could feed more people, using fewer resources. Scientists say the world needs to invest more in rice research if it is to hold off famine. Heda Bayron reports from the headquarters of the International Rice Research Institute in Los Baños, Philippines.

Farmers tend a rice field ripe for harvest. The rice stalks bend in the wind, heavy with golden grains.

The farmers chase birds away from the rice growing at the International Rice Research Institute, in the town of Los Baños.

As prices skyrocket, many fear that 700 million of the world's poor will be unable to afford rice.

At the institute, scientists race to find rice varieties that feed more people, but require fewer resources to grow.

Robert Zeigler, the institute's director, says there are no shortcut solutions to the rise in prices.

"Demand growth has continued steadily for the past 50 years, population growth continues, we have economic growth and development, all of which drive up food consumption... But production hasn't kept up with demand," he said.

Many factors have made it hard for rice farmers around the world to keep up with rising demand: increased competition for water, rising fuel and fertilizer costs and bad weather.

And land for farming grows scarce. Along the highway to the rice institute, factories, malls and houses stand on land that once held rice paddies. The problem is found all over Asia.

Zeigler says a second Green Revolution is the best way to solve the problem.

Scientific developments in the 1960s and 70s led to the first Green Revolution - increased farm yields in many developing nations, and lower rice prices, yet improved farm incomes. But for several years, yields have been flat in Asia's major rice growing region.

"This time around it's going to be much more complex," he said. "We can't depend upon area expansion or new land for agriculture, so we're going to have to increase productivity on existing land. So that's going to involve far better practices by farmers in terms of managing their water, managing their fertilizer, managing their labor. It would mean rice varieties, wheat varieties and maize varieties that are able to produce far more yield with the same inputs."

The institute says average rice yields must rise at an annual rate of at least 50 kilograms a hectare over the next 10 years to keep up with demand. But public investment in agriculture has fallen by a third from its level in the mid-1970s.

"We need a major commitment on the part of major national and international agencies to make sure the resources are there to drive that second Green Revolution. ? That includes irrigation infrastructure, farm-to-market roads and of course it includes research capacity," he said.

It is not lost on some people in the Philippines that the world's best rice researchers are based in the country, but still it suffers from rising prices. Just a few decades ago, the country grew enough to feed itself, but now it must import rice.

These poor Filipinos line up for hours to buy government-subsidized rice. Each person gets just three kilos at a time.

Inside the institute's seed vaults are 100,000 varieties of rice from all over the world, safeguarded for future generations.

Scientists study the genetics of the seeds, trying to breed more nutritious varieties and ones that can withstand floods and droughts. Successful varieties are given to farmers for planting.

But Zeigler says more studies must be done.

"We need to much more effectively tap into the genetic potential of rice," he said. "We need to understand better the ecology of the rice fields and how we can manage the rice fields such that insects, pests and diseases don't cause losses. We need to understand the soil and water ecology much better."

The institute needs $60 million a year to continue research and development. But its current budget is short by a third of that amount.

Zeigler and other institute officials have been knocking on donors' doors, carrying the message that now, more than ever, research may be the world's last line of defense against hunger.