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Castor an oilseed crop that can cure, kill you

Australian Nic George left is a UC associate specialistwho is working on oilseed research with UC Davis Cooperative Extension biofuels guru Steve Kaffka right They are standing beside a castor trial
<p> Australian Nic George, left, is a UC associate specialist,who is working on oilseed research with UC Davis Cooperative Extension biofuels guru Steve Kaffka, right. They are standing beside a castor trial.</p>
Castor beans are back in California as a possible source crop for making biofuels. Castor&#39;s main toxic protein, ricin, is so potent that a single milligram is sufficient to kill an adult. Castor oil is essential to the global specialty chemical industry because it is the only commercial source of hydroxylated fatty acids.

The latest entry into the California derby to find a profitable biofuel crop is one that can kill you, cure all that ails you and get you tossed into jail as a terrorist, if found in your possession.

It was featured in an article in the University California’s California Agriculture magazine as a potential new crop for California agriculture — in 1949.

You guessed it. Castor beans are back in California, at least as the latest research crop that University of California, Davis Cooperative Extension biofuels guru Steve Kaffka is looking at as a possible source crop for making biofuels.

Kaffka, is the director of the California Biomass Collaborative, a statewide assembly of government, industry, environmental groups and educational institutions administered for the state through UC Davis’ Energy Institute.

He is field testing a passel of potential biofuel crops: canola, camelina, meadowfoam, sugar beets, sweet sorghum, sugar cane, and switchgrass among others. Castor is the latest. It is the only one where there is "Do Not Cross" yellow tape circling the experimental plots.

The seed of a castor bean plant, Ricinus communis, contains two toxins that are poisonous to people, animals, and insects. The main toxic protein, ricin, is so potent that a single milligram is sufficient to kill an adult. Ricin is considered both a chemical and biological weapon and is explicitly prohibited by the Biological and Toxin Weapons Convention (BTWC). It is a slow-acting poison, with death occurring after 1-3 days.

The other toxic protein in the castor bean, RCA (Ricinus communis agglutinin), glues together red blood cells. Injection of RCA into the bloodstream essentially causes a person's blood to coagulate internally.

Toxin within the castor seed has been reported as seven times more deadly than cobra venom.

In the 1940s, the U.S. military experimented with using ricin as a possible warfare agent. In some reports ricin has possibly been used as a warfare agent in Iraq and more recently by terrorist organizations in Afghanistan.

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. U.S. Homeland Security and the FBI carefully monitor interest in castor production for this reason.

Castor history

However, castor oil and other processed products made from castor beans contain very little ricin or RCA.

Plant breeders have also have taken the vast majority of ricin out of newer castor varieties using biotech DNA market technology. However, it can be a problematic crop to grow and harvest, thus the precautions taken in Kaffka’s trials.

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. About $100 million worth of castor is imported into the U.S.

Kaffka told a field day audience at the West Side Research and Extension Center at Five Points, Calif., that the oil crop is worth $3,000 to $5,000 per ton, thus the renewed interest in it as a crop with an oil market today in the U.S. and a future market for biofuel.

Castor was in production as early as the mid-1850s in the central U.S, and more than 23 crushing mills reportedly were operational at that time. Baker Castor Oil Co. began a program to develop domestic production to supply their processing plant in California. Contracts were offered to growers, and limited production developed in the Imperial and San Joaquin Valleys. Derivatives of castor oil were key ingredients in hydraulic fluids, greases, and lubricants for military equipment during World War I and World War II. During and the Korean conflict, castor production was stimulated by a government sponsored procurement program. The production area reached more than 50,000 in 1951, mainly in Texas, Oklahoma, California and Arizona. By 1959, Texas became the leading producer of castor, and production was centered near Plainview . In the late 1960s, more than 75,000 acres were grown in Texas. A small crushing facility with solvent extraction was built in Plainview in the early 1960s by the Plains Cooperative Oil Mill of Lubbock. This plant operated until castor production ceased in the early 1970s.

Texas has taken up the castor call once again, and Kaffka is following on the recent research in Texas where researchers and growers there have found castor to be drought tolerant and reportedly salt tolerant.

Kaffka has trials in the San Joaquin Valley, Salinas, Imperial Valley and at UC Davis to verify that Texas work.

Major castor role pending

Texas researchers are taking another look at castor because of its high seed oil content for potential use in the production of specialty chemicals, biodiesel, and RFS2 renewable fuel.

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.

“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 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 Dick Auld, oilseed crop specialist and research scientist at Texas Tech University.

Last year at a Texas crop tour, 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.

“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 R.D. Brigham of the USDA Research Center in Lubbock, has provided promising results, effectively reducing ricin toxicity by 70 percent to 90 percent. A semi-dwarf variety, Brigham also allows for mechanized commercial production. Bingham is from Castagra, a Canadian bioproducts company.

“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,” Auld adds. Conventional breeding to rid castor of lethal ricin and troublesome allergens hasn't solved the problem. However, using biotechnology, scientists have been able to advance the breeding of ricin-reduced castor.

“Castor is certainly a crop that requires careful management, such as proper isolation from food crops and good hygiene practices,” Auld concedes.

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.

“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.

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.

Castor in California

“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.

And, maybe California, too.

"We estimate that would translate to about 200,000 acres of production in Texas or elsewhere to provide the oil alone," Trostle said.

Some people have suggested that all this concern over ricin levels in castor is much ado about nothing; that it's been grown in the past in the U.S. and nobody died from it. Trostle notes that he has not found in the literature any instance of someone getting sick or dying from handling castor. Still, he believes it is best to err on the side of caution in this instance. That would include strict guidelines for planting, growing, harvesting, transporting, selling and storing castor.

Purified ricin and RCA are of considerable concern as weapons for several reasons. First, castor bean seeds are readily obtainable. Second, several routes of exposure are possible (for ricin: inhalation, injection, or ingestion). Once the proteins are purified, the powdered toxin can be used to contaminate food or beverages. Ricin is heat-stable, so it can be applied to shrapnel within an explosive device. Ricin has reportedly been found in terrorists weapons in Afghanistan. Possibly the greatest concern about ricin used as a weapon is that symptoms of poisoning can easily be misdiagnosed.

As a terrorism agent, ricin can be used as a powder, a mist, a pellet, or can be dissolved in water or weak acid. It is a stable substance and does not break down easily in typical indoor or outdoor temperatures.

Probably the most famous ricin poisoning was in 1978. Georgi Markov, a Bulgarian writer and journalist who was living in London, died after he was attacked by a man with an umbrella. The umbrella had been rigged to inject a poison ricin pellet under Markov’s skin.

More recently, in 2008 an unemployed graphic designer who told investigators that he found making ricin an "exotic idea" pleaded guilty to possessing the deadly toxin in a hotel room in Las Vegas.

He poisoned himself and was hospitalized with breathing problems and placed on life support.

Castor bean grows wild.

It is widespread in the southern United States, where it has been introduced and naturalized. Castor bean has naturalized below 1,000 feet (300 m) elevation in the southern San Joaquin Valley, along the central and south coast, in the San Francisco Bay Area, and in Trinity County. It grows as a shrub in mild climates such as coastal Southern California, but can grow as an annual in colder climates.

Castor bean is frequently found in riparian areas, especially along the south and central coast, where it invades and displaces native vegetation. This plant is also common in abandoned fields, drainages, ditches, and along roadsides and railroad tracks.

(Considerable information is this article was gleaned from articles in Southwest Farm Press written by Logan Hawkes andby Clay Coppedge in Country World)

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