This species has been cultivated as a food crop for many hundreds of years and, in that time, several quite distinct forms have arisen. The nomenclature of these forms is confused, to say the least, and by no means universally accepted. We have followed the treatment used by GRIN, though it is very likely to be revised in the future[].

Common Name: Oilseed Rape

General Information

Oilseed rape is an erect to spreading, annual to biennial plant; branched above, it can grow from 30 - 150cm tall[].
Oilseed rape is one of the most cultivated plants in the world, widely grown from the temperate zone to the tropics for its oil-rich seeds which are used for food , biomass and industrial purposes.
A widely cultivated plant, it sometimes escapes from cultivation and becomes established - it has been described as invasive in countries such as New Zealand and the Galapagos Islands of Ecuador[].

Known Hazards

The oil contained in the seed of some varieties of this species can be rich in erucic acid which is used in industry but is toxic if consumed. However, modern cultivars have been selected for culinary use which are almost free of erucic acid[].

Botanical References

Range

Europe - Mediterranean. Naturalized in Britain[].

Habitat

Banks of streams, ditches and arable fields in Britain[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Annual/Biennial
Height	1.20 m
Pollinators	Bees, Self
Self-fertile	Yes
Cultivation Status	Cultivated

Cultivation Details

Oilseed rape is a plant of the temperate zone, where it is found mainly at low elevations but also ascending up to 2,000 metres - it can also be cultivated at higher elevations from 1,500 - 2,200 metres in the tropics. It grows best in areas where annual daytime temperatures are within the range 15 - 25°c, but can tolerate 5 - 41°c[]. When dormant, the plant can survive temperatures down to about -15°c, but young growth can be severely damaged at -6°c[]. It prefers a mean annual rainfall in the range 500 - 1,000mm, but tolerates 400 - 2,800mm[].
Succeeds in full sun in a well-drained fertile preferably alkaline soil[]. Succeeds in any reasonable soil[]. Prefers a heavy soil and cool moist conditions[, ]. Sunny days and cool nights are favourable for plant growth whilst dry weather at harvest time is essential[]. Prefers a pH in the range 6.5 - 7.6, tolerating 5.5 - 8[].
There are two main forms of oilseed rape and each form has many named varieties:-
Annual rape, or summer rape, (sometimes classified as Brassica napus annua (Schubl. & G. Martens) Thell.) is a spring-sown crop harvested in the summer. It can take from 85 - 160 days from sowing to harvesting the seed[].
Winter rape, canola or colza (sometimes classified as Brassica napus napus) is generally sown in the autumn and harvested in early to late summer.It can take from 160 - 340 days from sowing to harvest[].
Rapeseed oil is naturally high in erucic acid and glucosinolates, both of which have anti-nutritional properties but have industrial uses. Forms high in erucic acid have been developed for industrial use, whilst cultivars have also been developed that have a low content of erucic acid and glucosinolates and are therefore suitable for food.
Yields of 2 - 4 tonnes per hectare are considered good, while yields of 0.5 - 2 tonnes are more usual[].
Rape is 70% self-pollinating and 30% cross-pollinated. Even if wind and insects are absent, seed are still produced. Yield increases with honeybees[].
This species is closely related to Brassica rapa[].

Edible Uses

An edible oil is obtained from the seed, it is used mainly for cooking purposes, but also for salads[, , , , ]. Oil purchased for culinary use is perfectly safe and wholesome to use. However, do not press your own seeds for oil unless you are sure it is low in erucic acid - see the notes above on toxicity.

Leaves - raw or cooked[, , ]. Added to salads or used as a potherb[].

Immature flowering stems - cooked in much the same way as broccoli[].

The sprouted seed is often used as the mustard part of mustard and cress. Eaten in salads[, , , ].
The seed is ground into a powder and used as a mustard flavouring[].

Medicinal

The root is emollient and diuretic[]. The juice of the roots is used in the treatment of chronic coughs and bronchial catarrh[, ].

The seed, powdered, with salt is said to be a folk remedy for cancer[].

Rape oil is used in massage and oil baths, it is believed to strengthen the skin and keep it cool and healthy. Combined with camphor it is applied as a remedy for rheumatism and stiff joints[].

Agroforestry Uses:

The growth of this plant is inhibited by field mustard and hedge mustard growing nearby[, ].

Other Uses

The seed contains up to 45% of a semi-drying oil. Cultivars low in erucic acid are widely used for food, whilst other forms can be used as a luminant, lubricant, in soap making etc[, , , ].
Rapeseed oil has potential market in producing detergent lubrication oils, emulsifying agents, polyamide fibres, and resins, and as a vegetable wax substitute. According to the Chemical Marketing Reporter (April 26, 1982) 'the most common use for the oil is still in the production of erucic acid, a fatty acid used in turn in the manufacture of other chemicals[].
The oil can be used as a deisel substitute and is often cultivated for this purpose.

Propagation

Seed - sow spring or autumn in situ.