UC Davis tests jatropha for Chevron

Web exclusive posted Dec. 23, 2008, at 1:47 p.m. CST

Researchers at the University of California, Davis, are growing jatropha at three locations in California to test how the biodiesel feedstock fares in California's varied climates. According to Sham Goyal, an agronomist at the UC Davis Energy Institute, jatropha is being grown on two-acre plots in northern California near Davis, in central California near Bakersfield in the San Joaquin Valley and close to the Mexican border near El Centro.

"These three areas were chosen to represent three common and good crop production areas," said Goyal, who noted that there really wasn't much jatropha in California before last year. "The plants seem to be doing fine in all three locations, but they grow best in the southern locations obviously because those have warmer temperatures. Davis, on the other hand, has cooler nights, so the growth of the trees was not nearly as much as it was in the other two locations. We don't know yet whether that's a real disadvantage or not because our trees are still so young. They are not even one year old."

Goyal said the jatropha was planted in April. He is working on a team of four UC Davis researchers, including a geneticist and two agricultural engineers, under a program funded by a $25 million collaborative research investment from Chevron Corp. Chevron is working with the California Biomass Collaborative, a statewide collaboration of government, industry, environmental groups and educational institutions administered for the state by UC Davis, to pursue advanced technology aimed at converting cellulosic biomass into transportation fuels. The collaborative is sponsored by the California Energy Commission, and other agency and industry partners, including Chevron.

Chevron's investment in the collaborative focuses on renewable feedstocks available in California, as well as the development of new feedstocks that have been optimized for drought tolerance, minimal land requirements and harvesting technology. The five-year program began in 2006, and jatropha is one of the new feedstocks being developed for California by UC Davis. Goyal said he hopes the jatropha will begin bearing fruit next year and the following year. "We will know quite a bit about their real potential in these three climates," he added.

In addition to testing the hardiness and growth potential for jatropha in varied California climates, UC Davis scientists are looking at the underlying genetics of jatropha. "We have a lot of germplasm, but nobody really knows if one is different from the other," Goyal said. "Nobody really seems to understand the genetics behind it. We are going to do molecular biology and use fingerprinting to see if all of this material that we have here is really different or not different. If they are different, then how do we keep it true to the type? It is, we are told, a cross-pollinated crop." He said much of the science that is available in regard to jatropha has been completed in India.

Goyal and his team recently returned from India after having spent a few days in the first half of December testing equipment they have built for harvesting jatropha fruit. He described the equipment as very rudimentary. "It's not even a prototype," he said. "We are just testing the concept or principle of how we could possibly knock those fruits off the branches, what sort of energy would go into that, if it would damage the plants and so on." He said developing harvesting equipment is necessary if jatropha is to be grown as a biodiesel feedstock in the U.S. "Unless we can harvest this mechanically, there is no future in our country," he said. "We can't afford to have manual harvesting of jatropha. So unless we can effectively grow and effectively harvest mechanically, it will not happen for us."

Despite the hurdles, Goyal said there might be a future for jatropha as a California cash crop. "We are really optimistic and bullish," he said. "We are very excited because this is a hearty plant that can be grown in marginal lands, and so we're not going to be replacing a lot of the food crops by growing jatropha. With time and given appropriate resources, we should be able to make enough genetic improvements that it will be a very viable bioenergy crop."

Goyal said UC Davis is committed to developing jatropha. "We at the University of California are known to stick with our objectives a lot longer than many others do," he said. "We don't give up that easily. Jatropha as it stands right now, I'm sure, is still a wild species. There is little improvement or domestication that has occurred yet, and when there is a wild species that we need to cultivate for our interests, we need to domesticate it, which means we have to make genetic improvements. It's going to take time."