Chris Somerville, director of the Energy Biosciences Institute at the University of California, Berkeley, says he’s not that surprised by the study’s findings. “Jatropha is a wild species and probably has a terrible harvest index [ratio of yield to the total harvest] because no breeding has been done yet,” he says.

Somerville says that interest in jatropha was driven largely by European Union (EU) mandates for biodiesel production that were reduced in December 2008 due to environmental concerns that biofuels–in particular, biodiesel from palm oil–were causing the destruction of rain forests and wetlands. “I don’t know if we’ll see the death of jatropha, but we certainly see a lot less demand for it in Europe now than a couple of years ago, when there was a real scramble for it,” Somerville says.

Another recent study, carried out by Friends of the Earth, found that jatropha plantations in Swaziland run by BP and D1 Oils were taking land and water away from food crops in a country already suffering from chronic food shortages.

Somerville says that jatropha and other biodiesel crops will likely be pushed out by much higher yields of cellulosic ethanol in developed countries in the coming decade, but that the plants may continue to fill a niche. “The developing world may continue to see a big demand for jatropha and other vegetable oils because capital investment is much less than for ethanol and especially the highly technical processes of cellulosic fuels,” he says.

Henk Joos, who is the plant science director at D1 Oils, contends that the EU mandates still call for large quantities of biodiesel and says that newer, higher-yield strains of jatropha could solve many of the plant’s water-use issues. Joos and his team are crossbreeding different strains of jatropha to increase seed production and to maximize the seeds’ oil content, and they’re developing processes that allow the remaining seed biomass to be used for animal feed.

In 2006, the Energy and Resources Institute (TERI), an Indian research group, began a 10-year, $9.4 million effort to develop jatropha that included genetically engineering seeds to have higher oil content. Nibhi Chanana of TERI says that the group is still three to four years away from isolating the genes that control for oil production.