The University of California, Davis is conducting research on the oil plant jatropha to determine if the plant can be grown successfully and profitably in Southern California to produce biodiesel.

Jatropha seeds from India grown in a UC Davis greenhouse were transplanted this spring into an acre parcel at the University of California Desert Research and Extension Center (DREC) in Holtville, Calif. The trial is funded by Chevron.

Jatropha is a tropical, drought tolerant, perennial plant grown as a tree or shrub up to 13 feet in height. The fruit has three kidney-bean sized seeds which contain about 50 percent oil.

“I think jatropha would be ideal for this area,” said Sham Goyal, UC Davis agronomist, and a member of the university's jatropha research team. “A realistic estimate is an acre of jatropha could produce from 500 to 600 gallons of biodiesel per acre per year. If you're paying $5 per gallon for diesel, that's about $2,500 per acre of gross return.”

Jatropha produces fruit-seeds for about 30 years and grows best in well-drained soils with good aeration. The plant is well adapted for marginal soils with low nutrition. Plantings at DREC are sub-surface irrigated. Goyal says annual water requirements are about 2 acre feet.

The jatropha plant-to-biodiesel process includes cultivating the jatropha plantation, harvesting the nuts which contain oil and protein, mechanically grinding the oil seeds, pressing out the plant oil, and filtering the plant oil.

Goyal says labor issues would necessitate mechanization at harvest.

“If we cannot harvest the crop mechanically, then jatropha has no future,” Goyal said. “Seed harvest by hand would be too expensive.” Mechanical harvesters are in development in other countries.

Another concern is fully mature and immature fruits exist on the same branch at the same time which would make mechanical harvesting more difficult. Genetic plant developments are needed to create uniform maturity, Goyal says.

Goyal shared his jatropha knowledge with growers, pest control advisors, and industry representatives during the 19th annual Fall Desert Crops Workshop in November in Holtville.

The event was organized by Eric Natwick, director, University of California Cooperative Extension, Imperial County. Western Farm Press sponsored the workshop.

The recommended jatropha planting rate is about 1,000 plants per acre, Goyal says. The plants in the DREC plot are planted 6 feet apart with 15 feet between the rows.

Jatropha tolerates drought, but irrigation and rainfall increases productivity. The plant flowers between September and November and grows fruit from October to December. The best average temperatures for production are the mid-70 degree range.

In addition to Goyal, UC Davis jatropha researchers include plant scientist Anna Davidson, ag engineers Uriel Rosa and Shrini Upadhyaya, and plant geneticist Dan Parfitt.

Goyal was born and raised in India earning his bachelor and master's degrees there. His doctorate in plant physiology is from UC Davis. The university's first effort to find a sponsor for a jatropha project fell short. Chevron came on board last year. Goyal then traveled to India to collect seeds and germplasm.

Goyal is unaware of potential pest or disease issues with jatropha.

Historically jatropha is grown as a live fence around fields in some areas of the world to keep cattle away from crops. Animals don't eat it. Some people say jatropha is poisonous. The subsequent discovery of high oil content has elevated the plant as a new oil source for biodiesel.

The plant may have originated in Nicaragua. Most jatropha growing areas in the world are based around the equator. Jatropha, from the family Euphorbiaceae, is commonly known as Barbados nut and White Physic nut.

Goyal referred to a global jatropha market study which pegs production in the Americas at more than 64,000 acres this year. Production could total four million acres by 2015. Asia is expected to grow 2.3 million acres this year and surpass 22 million acres by 2015.

Several Indian companies have jatropha lines capable of producing 60 percent oil, Goyal says. This goal would require superior plant genetics, advanced pruning techniques, improved soil moisture and nutrient levels, foliar fertilizer 30 days prior to harvest, and high-end processing equipment.

Processing typically should be completed within 24 hours of harvest, Goyal says.

Byproducts can create paper, soap, cosmetics, toothpaste, rich organic fertilizer seed cake, biomass to power electricity power plants, plus medicinal uses.

William Castellanos and Charlie Tijerine are conducting on-farm jatropha test trials in Desert Center, Calif., (Riverside County). Both attended the workshop to hear Goyal's presentation.

Castellanos of William's Fish Farms, planted jatropha seeds in 1-gallon pots in his greenhouse last July and then transferred the plants to 5-gallon pots. He'll transplant the 500, 24 to 30-inch plants into a one-half acre parcel in February.

“Jatropha used for pasture field dividers grow like weeds in El Salvador,” said Castellanos, an El Salvador native.

“I expect to have the plants in the ground for one year before harvesting seeds.” He noted that jackrabbits like to eat his plants. “I don't want to work for the jackrabbits.”

Neighbor Charlie Tijerine, Desert Center Cactus, and a former cotton grower in Buckeye, Ariz., planted and lost about 500 plants this year; likely due to planting too early. He also believes the seed he purchased from India was old seed. He may purchase seed from Australia next time.

“My plan is to establish a 40-acre nursery,” Tijerine said. “I think there will be a big demand for jatropha.”

Tijerine plans to tap into his cotton roots. “I think jatropha can be planted similar to cotton,” he said. “When the heat builds up, they'll germinate if it's good quality seed. Good seed combined with deep tillage and a good irrigation system should allow it to grow.” Tijerine will grow strawberries or tomatoes between the jatropha rows.

Tijerine said a processing facility able to handle jatropha is located in Los Angeles and a plant may be built near Vicksburg, Ariz., (La Paz County).

“I think getting a cash flow from 18 months to three years would be a good guess because it's an exotic plant. If you can get cash flow within two years, it would be pretty good,” Tijerine said.

The Fall Desert Crops Workshop was supported by commercial sponsors including: BASF, Booth Machinery, and Bayer CropScience (Platinum Sponsors); Dow AgroSciences, Rain Bird, Syngenta, Tessenderlo Kerley, and Valent (Gold Sponsors), FMC (Silver Sponsor); and Certis (Bronze Sponsor).