FARIDABAD, India — Indians know better than to eat the plum-sized fruit of the wild jatropha bush. It's poisonous enough to kill.

But with oil prices surging, the lowly jatropha is experiencing a renaissance of sorts — as a potential source for fuel for trucks and power stations. The government has identified 98 million acres of land where jatropha can be grown, hoping it will replace 20 percent of diesel consumption in five years.

"We have found that we can produce biodiesel from it. If we can keep the price down, the future looks bright," says R.K. Malhotra, who oversees the Indian Oil Corp.'s research center that is running tests on the oil.

India isn't alone. All across Asia, governments are searching for crops that can help them offset a dependence on imported oil that can only skyrocket as their economies soar. Palm oil and sugar cane are the dominant crops in the region, but everything from coconuts to castor oil to cow dung is being tested for fossil-fuel alternatives such as ethanol and biodiesel.

Most experts also believe that, using current technologies, there isn't enough land to make a serious dent in oil consumption. Some scientists say production will consume more conventional energy than it will save, and environmentalists came out this month against plans by Indonesia to convert millions of acres of rain forest on the island of Borneo into palm oil plantations.

Georgia Tech Professor Arthur Ragauskas, who co-authored a study of biofuels published in Science magazine, sees other potential pitfalls.

"One criticism of biofuels is that if you want to go from 2 percent to 20 percent, you would have to direct so much of that agriculture from food to fuel that there would be real competition between the two," he said.

"Even worse, if we have a famine in part of the world, we would have to make a decision as a society between food or fuel."

For now, alternative fuels are less than 1 percent of current fuel usage in most of Asia, and experts say their large-scale use is years if not decades away.

Still, "Every country in Asia is trying to commercialize and put up legislation on biofuels," said Conrado Heruela, a renewable energy specialist with the U.N. Food and Agriculture Agency.

"Right now, the target is not that big but it will be very significant in the long term," he said.

Ethanol, distilled mostly from corn in the United States and from sugar in Brazil and Asia, is mixed with petroleum. Biodiesel comes mostly from rape seed in Europe, vegetable oil in the United States and palm oil, coconut oil and jatropha in Asia, and is mixed with diesel.

Ethanol produces 13 percent less greenhouse gases than fossil fuels, a study published recently in Science magazine found, while the U.S. Department of Agriculture says biodiesel can reduce carbon emissions by 78 percent.

Thailand's King Bhumibol Adulyadej has a car that runs on palm oil and has been touting the substitute fuel to his nation for more than 20 years. Today, hundreds of gas stations in the capital, Bangkok, sell gasohol — gasoline with 10 percent ethanol — and it's slightly cheaper than regular gas.

Thailand also grants the sugar industry tax breaks to produce ethanol and is following the United States in a plan to replace the toxic fuel additive MTBE with ethanol. Still, supply is not matching demand.

On some Pacific islands, whose isolation makes oil imports more costly and vulnerable to market shifts, power companies are looking for other sources.

"The use of alternative fuels is very much the topic of the moment among the small utilities in the Pacific," said Jean Chaniel, the general manager of Unelco Vanuatu, whose company runs some generators on 5 percent coconut oil.

The Fiji Electricity Authority plans to switch entirely to renewable energy by 2011.

India says it wants to increase its use of renewable energy from 5 percent to 25 percent by 2030. Much of this will come from nuclear plants, but it is also examining wind power and other methods including jatropha.

About half of India drives on gasoline with 5 percent ethanol, and the government aims to increase that to 20 percent in the next decade.

In China, the government is promoting ethanol and is financing nuclear, hydroelectric and solar power, aiming to increase renewable energy sources from 7 percent up to 15 percent by 2020.