Everything about Rapeseed totally explained
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. 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's 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 (due to its very high
lipid and medium protein content), and is a leading option for Europeans to avoid importation of
GMO products.
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, 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 low erucic acid rapeseed. Sometimes the "Canola-quality" label is applied to other varieties as well.
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. 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 "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's 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'll 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. 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.
Some UK farmers (such as Hillfarm Oils
(External Link
)) & Farrington Oils
(External Link)) 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, due 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) due 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 as 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, 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's 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.
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
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.
Further Information
Get more info on 'Rapeseed'.
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