Rapeseed
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Rapeseed Brassica napus, also known as Rape, Oilseed Rape, Rapa, Rapaseed and (one particular cultivar) Canola, is a bright yellow flowering member of the family Brassicaceae. The name is derived through Old English from a term for turnip, rapum. Some botanists include the closely related Brassica campestris within B. napus. (See Triangle of U)
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Cultivation and uses
It is very widely cultivated throughout the world 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. The FAO reports that 33 million tonnes of rapeseed was produced in 2002. In Europe, rapeseed is primarily cultivated for animal feed (due to its very high lipid and medium protein content), and is a leading option for Europeans to avoid importation of GMO products.
Canola.jpg
Natural rapeseed oil contains erucic acid, which is mildly toxic to humans in large doses but is used as a food additive in smaller doses. Canola is one of many selected cultivars of rapeseed bred to have a low erucic acid content. Canola was developed in Canada and its name is a contraction of "Canadian oil, low acid". The name was also chosen partly for marketing reasons, so successfully that the name is sometimes mis-applied to other cultivars of rapeseed.
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.
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. 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.
Rapeseed leaves are also edible, similar to those of the related kale. Some varieties of rapeseed are sold as greens, primarily in Asian groceries.
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.
Rapeseed and health
Brassicanapus2web.jpg
Rapeseed has been linked with adverse effects in asthma and hay fever sufferers. Some suggest that oilseed pollen is the cause of increased breathing difficulties. This is unlikely however, as rapeseed is an entomophilous crop, with pollen transfer primarily by insects. Others suggest that it is the inhalation of oilseed rape dust that causes this, and that allergies to the pollen are relatively rare. There may also be a another effect at work; since rapeseed in flower has a distinctive and pungent smell, hayfever sufferers may wrongly jump to the conclusion that it is the rapeseed that is to blame simply because they can smell it.
Controversy
Monsanto has genetically engineered new cultivars of Rapeseed that are resistant to the effects of the 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. There is also major concern that the extensive use of herbicide leads to significant loss of biodiversity as wildflowers ("weeds") are killed, leaving other wildlife dependent on the wildflowers unable to survive.
Production
Worldwide production of rapeseed rose to 36 million tonnes in 2003 (source FAO).
| Area planted | Yield | Production | |
| millions of hectares | kg per hectare | millions of tonnes | |
| World | 23.69 | 1516 | 35.93 |
| China | 7.20 | 1597 | 11.50 |
| EU (15) | 3.10 | 3060 | 9.49 |
| Canada | 4.69 | 1422 | 6.67 |
| India | 4.80 | 760 | 3.65 |
| Germany | 1.27 | 2866 | 3.64 |
| France | 1.08 | 3084 | 3.32 |
| UK | 0.46 | 3994 | 1.84 |
| Australia | 1.50 | 947 | 1.42 |
| Poland | 0.43 | 1767 | 0.75 |
| USA | 0.43 | 1586 | 0.69 |
Pests and diseases affecting canola
Insect pests
- 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
See also
Reference
FAO. December 2004 oilcrops market assessment (http://www.fao.org/es/esc/en/20953/21017/highlight_27527en.html), 2004
External links
- Canola Council on truth and myths about Canola (http://www.canola-council.org/cooking_myths.html)
- Origins of Canola oil is toxic falsehood. (http://www.snopes2.com/toxins/canola.htm)bg:Рапица
cy:Rêp de:Raps es:Colza fr:Colza it:Colza nl:Koolzaad ja:アブラナ