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 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 , and is a leading option for Europeans to avoid importation of GMO products.
Natural rapeseed oil contains 50% erucic acid, which is mildly toxic to humans in large doses but is used as a food additive in smaller doses. Wild type seeds also contain high levels of glucosinolates , 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." that was used by the Manitoba government to label the seed during its experimental stages, is now a tradename for 'double low' have started to produce cold-pressed rapeseed oil as a cooking oil and dressing.
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 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.
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 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.
The has 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.
Worldwide production of rapeseed rose to 46.4 million metric tons in 2005, the highest recorded total .
Pests and diseases
* Harlequin bug
* Flea beetles ,
* Diamondback moths ,
* Bertha armyworms ,
* Root maggots
* Lygus bugs
* Bronzed field beetle larvae
* Snails and slugs
* 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.