In a time when bio-security and foreign oil dependency share the spotlight as major issues facing the nation, it comes as no surprise that the idea of growing castor on U.S. soil and extracting castor oil for biofuels and industrial use is a growing controversy with supporters on both sides of the question: Would the benefits outweigh the risks?
On one hand there is little or no commercial castor production in the U.S. Nearly all castor oil used in the U.S. is imported from India, China and Brazil. But because of its high seed oil content, castor has tremendous potential as an oilseed crop in North America, especially in parts of the Southwest. The increasing demand and potential use of castor oil in the production of specialty chemicals, biodiesel, and RFS2 renewable fuel has generated considerable interest by several companies in developing commercial castor oil production in this country. Since castor grows well on marginal land, it represents an alternative crop suitable for production in select areas of Texas.
On the other hand, castor production comes with a reputation, largely related to the fear of growing a potentially toxic crop. Ricin, a protein toxin found only in the endosperm of castor seed, can represent up to 5 percent of the meal weight remaining after oil extraction. It could pose a threat if not carefully isolated and controlled as there is a concern the meal could be refined and used as a bioterrorism agent.
The U.S. Centers for Disease Control (CDC) classifies ricin as a Class B biological terrorism threat, identifying it as an agent that can be disseminated relatively easy. Ricin is not only poisonous but deadly if inhaled, injected or digested, raising fears that in the wrong hands the protein could be weaponized and used by terrorists. U.S. Homeland Security and the FBI carefully monitor interest in castor production for this reason.
Believing we can have our cake and eat it too, a group of Texas A&M and Texas Tech researchers have been working together on a castor variety that greatly reduces risk and still offers value in production. Working with the best tools agricultural science can offer, they have aggressively developed a semi-dwarf castor variety with reduced ricin levels and one that allows for mechanized production.
Getting to the oil
The oil produced by castor is essential to the global specialty chemical industry because it is the only commercial source of hydroxylated fatty acids. It is used by industry for a number of applications and the demand for the oil is high. In addition, there may be no better crop to use than castor to produce bio-fuels, making the product an ideal option to reduce dependency on petroleum.
“With castor seed producing as much as 50 percent oil and its ability to grow productively on marginal land, it represents a crop that could address a growing demand for castor oil. India virtually controls the global market now, and there is potential for domestic production,” reports Dr. Calvin Trostle, associate professor and research scientist at Texas A&M AgriLife in Lubbock.
“Castor production will play a major role for many years to come,” agrees Dr. Dick Auld, oilseed crop specialist and research scientist at Texas Tech University. “At one time some 70,000 acres in Texas were dedicated to castor farming. But when prices fell in the 1970s interest faded, and concerns over ricin and the potential for contamination of food crops overshadowed interest for its return.”
With a federal mandate to ramp up production of biofuels in the years ahead, Trostle and Auld agree there is a growing interest in domestic oilseed production, including castor.
Last year at a Texas crop tour, Dr. Travis Miller, AgriLife Extension program leader and associate department head for the department of soil and crop sciences at Texas A&M University, told attendees a successful castor industry will require isolating castor seed and using a number of strategies to insure it remains only in industrial oil handling and marketing channels. In other words, modern bio-engineering holds the key to reducing ricin levels and toxicity and combined with appropriate management and controls, castor will soon present itself as a safe oilseed alternative.
“The long term solution is to develop castor varieties that greatly reduce toxicity, and we’re well on the road to achieving this goal,” Auld explains.
A new variety known as the Brigham, so named after the advancement of castor research by Dr. R.D. Brigham of the USDA Research Center in Lubbock, has provided promising results, effectively reducing ricin toxicity by 70 to 90 percent. A semi-dwarf variety, Brigham also allows for mechanized commercial production.
“And this is just a start. We are working to further reduce ricin levels in an effort to make the plant safe. We would like to reduce ricin levels to 3 percent. Add to this the plant’s ability to grow well on marginal land, and it becomes a promising oilseed for Texas growers,” Auld adds.
Working against the idea of commercial production of castor in Texas is the perception that castor is simply not safe to grow given its potential as a bio-weapon and the potential threat it poses to food crop and farm animal operations.
“Castor is certainly a crop that requires careful management such as proper isolation from food crops and good hygiene practices,” Auld concedes. “No one wants to contaminate the food supply, but continued research will see the development of new varieties with lower toxicity.”
Trostle adds that researchers are recommending stringent management and control measures, such as dedicating combines to castor-only applications, taking safeguard in transportation and storage of castor seed to eliminate contamination and restrictions on growing food crops on fields used for castor.
“Businesses that initially sought to resume castor production in 2009 in Texas were considering using bagging equipment to store the grain on-farm until shipment. This is a good idea because it keeps castor out of commercial delivery points and storage facilities,” cites a recent Texas A&M report about castor production. In addition, the report says castor seed must not be mixed with any food or feed grains or any other crop that might be used for human or animal consumption.
“Certainly we need to proceed with utmost care and careful consideration of every safety issue. No one wants to proceed without making certain each issue has been adequately addressed,” he says.
But as demand grows for less dependency on foreign oil and demand for biofuel rises in the months and years ahead, scientists working with castor research believe there is a place for castor production in Texas.
“Especially in areas like the Trans-Pecos region where high salt content has made growing other crops difficult,” says Auld.
Currently castor trials continue on test plots in that region and also in the Lubbock area, and some testing of Brigham castor have been staged in the Coastal Bend and in Southeast Texas.
“We may be two or three years away from producing the best variety for commercial application in Texas, one that is safe, highly productive and easily managed. The potential is there, and castor could one day soon find a home on Texas soil,” says Trostle.