Rapeseed

taxobox
name = Rapeseed


image_caption = Rapeseed ("Brassica napus")
regnum = Plantae
unranked_divisio = Angiosperms
unranked_classis = Eudicots
unranked_ordo = Rosids
ordo = Brassicales
familia = Brassicaceae
genus = "Brassica"
species = "B. napus"
binomial = "Brassica napus"
binomial_authority = L. [cite web
url=http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?7661
title=Brassica napus information from NPGS/GRIN
publisher=www.ars-grin.gov
accessdate=2008-03-27
last=
first=] |

Rapeseed ("Brassica napus"), also known as rape, oilseed rape, rapa, rapaseed and (in the case of one particular group of cultivars) canola, is a bright yellow flowering member of the family Brassicaceae (mustard or cabbage family). The name derives from the Latin for turnip, "rāpum" or "rāpa", and is first recorded in English at the end of the 14th century. Older writers usually distinguished the turnip and rape by the adjectives "round" and "long"(-"rooted") respectively. [ [http://dictionary.oed.com/ OED Online] ] See also "Brassica napobrassica", which may be considered a variety of "Brassica napus". Some botanists include the closely related "Brassica campestris" within "B. napus". (See Triangle of U)

Cultivation and uses

Rapeseed is grown for the production of animal feed, vegetable oil for human consumption, and biodiesel; leading producers include the European Union, Canada, the United States, Australia, China and India. In India, it is grown on 13% of cropped land. According to the United States Department of Agriculture, rapeseed was the third leading source of vegetable oil in the world in 2000, after soybean and oil palm, and also the world's second leading source of protein meal, although only one-fifth of the production of the leading soybean meal. World production is growing rapidly, with FAO reporting that 36 million tonnes of rapeseed was produced in the 2003-4 season, and 46 million tonnes in 2004-5. In Europe, rapeseed is primarily cultivated for animal feedFact|date=February 2007 (owing to its very high lipid and medium protein contentFact|date=February 2007), and is a leading option for Europeans to avoid importation of GMO productsFact|date=February 2007. Natural rapeseed oil contains 50% erucic acid, which is mildly toxic to humansFact|date=July 2008 in large doses but is used as a food additive in smaller doses. Wild type seeds also contain high levels of glucosinolates (mustard oil glucosindes), chemical compounds that significantly lowered the nutritional value of rape seed press cakes for animal feed. Canola, originally a syncopated form of the abbreviation "Can.O., L-A." (Canadian Oilseed, Low-Acid) that was used by the Manitoba government to label the seed during its experimental stages, is now a tradename for 'double low' (low erucic acid and low glucosinolate rapeseed. Sometimes the "Canola-quality" sticky note is applied to other varieties as well [Canola-quality Brassica juncea, a new oilseed crop for the Canadian prairies .DA Potts, GW Rakow, DR Males - New Horizons for an old crop. Proc 10th Intl Rapeseed Congr, Canberra, Australia, 1999] .

The rapeseed is the valuable, harvested component of the crop. The crop is also grown as a winter-cover crop. It provides good coverage of the soil in winter, and limits nitrogen run-off. The plant is ploughed back in the soil or used as bedding. On some ecological or organic operations, livestock such as sheep or cattle are allowed to graze on the plants.

Processing of rapeseed for oil production provides rapeseed animal meal as a by-product. The by-product is a high-protein animal feed, competitive with soyaFact|date=February 2007. The feed is mostly employed for cattle feeding, but also for pigs and chickens (though less valuable for these). The meal has a very low content of the glucosinolates responsible for metabolism disruption in cattle and pigsFact|date=February 2007. Rapeseed "oil cake" is also used as a fertilizer in China, and may be used for ornamentals, such as Bonsai, as well.

Rapeseed leaves and stems are also edible, similar to those of the related bok choy or kale. Some varieties of rapeseed (called , yóu cài, lit. "oil vegetable" in Chinese; "yau choy" in Cantonese; "cải dầu" in Vietnamese; and 菜の花, "nanohana" in Japanese) are sold as greens, primarily in Asian groceries, including those in California where it is known as "yao choy" or tender greens.

Rapeseed is a heavy nectar producer, and honeybees produce a light colored, but peppery honey from it. It must be extracted immediately after processing is finished, as it will quickly granulate in the honeycomb and will be impossible to extract. The honey is usually blended with milder honeys, if used for table use, or sold as bakery grade. Rapeseed growers contract with beekeepers for the pollination of the crop.

Nutritional value

Canola oil (or rapeseed oil) contains both omega-6 and omega-3 fatty acids in a ratio of 2:1 and is second only to flax oil in omega-3 fatty acid. Canola oil's proponents claim that it is one of the most heart-healthy oils and has been reported to reduce cholesterol levels, lower serum tryglyceride levels, and keep platelets from sticking together.

Other sources (such as The Weston Price Foundation [http://www.westonaprice.org/knowyourfats/conola.html] ) have well researched concerns about the possible health risks of Canola oil: animal testing that indicates growth retardation, a higher incidence of heart lesions of the myocardium, decrease in platelet count and increase in platelet size, vitamin E deficiency, high blood pressure, and lowered life spans. In many of these studies, when saturated fats were added to the diets, health improved. There is also the concern that the modern process of extracting the oils with high-pressure mechanical pressing along with industrial solvent residue in the oil such as Hexane in itself can be toxic. These heat, high pressure and solvent processing methods [http://www.westonaprice.org/knowyourfats/conola.html] are common with most contemporary vegetable oils. Since omega-3 fatty acids rapidly become offensive smelling and subject to rancidification when processed with high heat and oxygen, the oil is then subjected to a deodorizing process which removes much of the Omega-3 and replaces it with trans fats. The actual claims of the Omega 3 content of processed canola oil have been challenged by a study [http://www.westonaprice.org/knowyourfats/conola.html] done at the University of Florida which found trans fat levels of up to 4.6 in commercial canola oil as opposed to the Canadian Governments assertion that the oil has 0.2 percent trans fat. Because of concerns about inhibited growth in human infants, canola oil is not permitted in infant formula by the FDA.

Some UK farmers (such as Hillfarm Oils [http://www.hillfarmoils.com] ) & Farrington Oils [http://www.farrington-oils.co.uk] ) have started to produce cold-pressed rapeseed oil as a cooking oil and dressing.

Biodiesel

Rapeseed oil is used in the manufacture of biodiesel for powering motor vehicles. Biodiesel may be used in pure form in newer engines without engine damage, and is frequently combined with fossil-fuel diesel in ratios varying from 2% to 20% biodiesel. Formerly, owing to the costs of growing, crushing, and refining rapeseed biodiesel, rapeseed derived biodiesel cost more to produce than standard diesel fuel. Prices of rapeseed oil are at very high levels presently (start November 05) owing to increased demand on rapeseed oil for this purpose. Rapeseed oil is the preferred oil stock for biodiesel production in most of Europe, partly because rapeseed produces more oil per unit of land area compared to other oil sources, such as soy beans.

Health effects

Rapeseed has been linked with adverse effects in asthma and hay fever sufferers. Some suggest that oilseed pollen increases breathing difficulties. But this is unlikely as rapeseed is an entomophilous crop, with pollen transfer primarily by insects. Others suggest that this is caused by the inhalation of oilseed rape dust [Oilseed rape allergy presented as occupational asthma in the grain industry. http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=9761021&dopt=Abstract] , and that allergies to the pollen are relatively rare. It may also be that since rapeseed in flower has a distinctive and pungent smell, hay fever sufferers wrongly blame the rapeseed just because they can smell it. An alternative explanation may be that it is simply the sheer volume of rapeseed pollen in the air around farmland which triggers an allergic reaction in hayfever sufferers on inhalation, or following prolonged exposure to high levels.

Controversy

The Monsanto Company has genetically engineered new cultivars of rapeseed that are resistant to the effects of its herbicide Roundup. They have been vigorously prosecuting farmers found to have the "Roundup Ready" gene in Canola in their fields without paying a license fee. These farmers have claimed the "Roundup Ready" gene was blown into their fields and crossed with unaltered Canola. Other farmers claim that after spraying Roundup in non-Canola fields to kill weeds before planting, "Roundup Ready" volunteers are left behind, causing extra expense to rid their fields of the weeds.

In a closely followed legal battle, the Supreme Court of Canada found in favor of Monsanto's patent infringement claim for illegal growing of "Roundup Ready" in its 2004 ruling on Monsanto Canada Inc. v. Schmeiser. The case garnered international controversy as a court-sanctioned legitimation for the global patent protection of genetically modified crops. However, Schmeiser was not required to pay damages as he did not benefit financially from the GMO crop in his field. More recently, in March 2008, an out-of-court settlement between Monsanto and Schmeiser has an agreement for Monsanto to clean up the entire GMO-canola crop on Schmeiser's farm at a cost of $660,000.

Production

Worldwide production of rapeseed (including canola) rose to 46.4 million metric tons in 2005, the highest recorded total (source: FAO).

Pests and diseases

Animal pests

* Harlequin bug ("Murgantia histrionica")
* Flea beetles ("Phyllotreta" sp.),
* Diamondback moths ("Plutella xylostella"),
* Bertha armyworms ("Mamestra configurata"),
* Root maggots ("Delia" sp.)
* Grasshoppers
* Lygus bugs ("Lygus")
* Bronzed field beetle larvae
* Snails and slugs

Diseases

* Beet Western Yellows virus
* Blackleg, caused by the fungus "Leptosphaeria maculans"
* Clubroot, caused by protist "Plasmodiophora brassicae"
* Sclerotinia white stem rot
* White rust disease, caused by the fungus "Albugo candida"

Genome sequencing and genetics

The 'A' genome component of the amphidiploid Rapeseed species "B. napus" is currently being sequenced by an international consortium. [cite web
title=The www.brassica.info website for the Multinational Brassica Genome Project
url=http://www.brassica.info]

See also

* Canola
* Biosafety
* Transgenic plants
* Triangle of U
* Brassica

References

External links

* [http://database.prota.org/dbtw-wpd/exec/dbtwpub.dll?AC=QBE_QUERY&BU=http%3A%2F%2Fdatabase.prota.org%2Fsearch.htm&TN=PROTAB~1&QB0=AND&QF0=Species+Code&QI0=Brassica+napus&RF=Webdisplay PROTAbase on "Brassica napus"]
* [http://www.canola-council.org/cooking_myths.html Canola Council on truth and myths about Canola]
* [http://www.snopes2.com/toxins/canola.htm Origins of "Canola oil is toxic" falsehood.]
* [http://www.wsu.edu/~gmhyde/433_web_pages/433Oil-web-pages/Rapeseed1/Rape&Canola_oils_1.html Extracting and refining rapeseed oil]
* Organisation for Economic Co-operation and Development (05-Dec-2001). [http://www.olis.oecd.org/olis/2001doc.nsf/43bb6130e5e86e5fc12569fa005d004c/19f31700dc91b614c1256b19003bd79d/$FILE/JT00118009.PDF CONSENSUS DOCUMENT ON KEY NUTRIENTS AND KEY TOXICANTS IN LOW ERUCIC ACID RAPESEED (CANOLA)] . ENV/JM/MONO(2001)13. Retrieved 2006-11-27
* University of Melbourne (1999) Multilingual multiscript plant name database. [http://www.plantnames.unimelb.edu.au/Sorting/Brassica.html Brassica names] . General Botanical Index. Retrieved 2006-11-27
* [http://www.gmo-safety.eu/en/oilseed_rape/ Safety research: GM oilseed rape] Oilseed rape in the environment and in agriculture
* [http://www.canolainfo.org CanolaInfo]
* [http://www.bbc.co.uk/radio4/factual/foodprogramme_20070204.shtml BBC Radio 4 Food Programme on rapeseed oil]