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Rapeseed (Brassica napus)
Rapeseed (Brassica napus)
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Brassicales
Family: Brassicaceae
Genus: Brassica
Species: B. napus
Binomial name
Brassica napus

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.[2] 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).


[edit] 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 feed[citation needed] (owing to its very high lipid and medium protein content[citation needed]), and is a leading option for Europeans to avoid importation of GMO products.[citation needed]

Canola seeds

Natural rapeseed oil contains 50% erucic acid, which is mildly toxic to humans[citation needed] 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 [what does this mean?] is applied to other varieties as well[3].

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 soya[citation needed]. 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 pigs[citation needed]. 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.

[edit] 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.

According to the Weston Price Foundation, Canola oil can have a number of health risks associated with it, as much of the omega-3 fatty acids listed in the nutrition information on the label are converted to transfats during modern refining processes and using it to cut out saturated fats can leave consumers vulnerable to other heart related problems through a lack of saturated fats in the diet.[4]

[edit] Biodiesel

Rapeseed field

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.

[edit] Health effects

Rapeseed flowers

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[5], 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.

[edit] Controversy

The Monsanto Company has genetically engineered new cultivars of rapeseed that are resistant to the effects of its herbicide Roundup. They have sought compensation from 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 unlicensed 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[6].

[edit] Production

Top Rapeseed Producers - 2005
(million metric ton)
 China 13.0
 Canada 8.4
 India 6.4
 Germany 4.7
 France 4.4
 United Kingdom 1.9
 Poland 1.4
 Australia 1.1
World Total 46.4
UN Food & Agriculture Organisation (FAO)
Worldwide Rapeseed Production
(million metric ton)
1965 5.2
1975 8.8
1985 19.2
1995 34.2
2005 46.4
UN Food & Agriculture Organisation (FAO)

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

[edit] Pests and diseases

[edit] Animal pests

[edit] Diseases

[edit] Genome sequencing and genetics

The 'A' genome component of the amphidiploid Rapeseed species B. napus is currently being sequenced by an international consortium.[7][dated info]

[edit] See also

[edit] References

  1. ^ "Brassica napus information from NPGS/GRIN". www.ars-grin.gov. http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?7661. Retrieved on 2008-03-27. 
  2. ^ OED Online
  3. ^ 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
  4. ^ [1]
  5. ^ 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
  6. ^ Monsanto Press Release, March 19, 2008. http://www.monsanto.ca/about/news/2008/03_19_08.asp
  7. ^ "The www.brassica.info website for the Multinational Brassica Genome Project". http://www.brassica.info. 

[edit] External links

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