Rape (Brassica napus L. var. napus)

Common Name:


Scientific Name:

Brassica napus L. var. napus


Brassica campestris f. annua Schubl. & G. Martens, Brassica campestris f. biennis Schubl. & G. Martens, Brassica campestris subsp. napus (L.) Hook. f. & T. Anderson, Brassica napus f. annua (Schubl. & G. Martens) Thell., Brassica napus f. biennis (Schubl. & G. Martens) Thell., Brassica napus subsp. oleifera (Delile) Sinskaya, Brassica napus var. annua W. D. J. Koch, Brassica napus var. biennis (Schubl. & G. Martens) Rchb., Brassica napus var. oleifera Delile





Originated in the Mediterranean region and quickly adapted to much of Asia and Europe.

Time of introduction:


Rape is a biennial leafy forage crop that is distributed throughout temperate regions. It has a branched inflorescence with an elongating raceme. Flowers are pale yellow and 1.2-1.5 cm long. Due to its thin taproot system, rape can be grazed, regrown, and grazed again. Rape is sometimes chopped and hand-fed in order to reduce waste associated with trampling by livestock. Waste can also be reduced if pastures are cross-fenced and the grazing period limited to a few hours each day. As a member of the Cruciferae family, rape requires relatively large quantities of sulfur for good growth. Cultivars can be devided into two types, giant and dwarf. Giant has larger stems and branch less than dwarf. types, while having better dry matter yields and general acceptability than dwarf types.

Life cycle (annual/biennial/perennial):

Annual, Biennial

Growth habit & Regrowth type:

Invasive potential:



Image Gallery: The OSU Forage Information System contains an Image Gallery that includes Rape photographs and drawings useful in identification. The URL for the gallery is: http://forages.oregonstate.edu/main.php?PageID=241

The direct URL for Rape is: http://forages.oregonstate.edu/main.php?PageID=178&SpecID=38

Inflorescence: The inflorescence is branched, up to 1 m tall as an elongating raceme; silique 5-11 cm long, 2.5-4 mm wide, with slender beak 0.5-3 mm long. Underground part curved or crooked for 5-7.5 cm and then dividing into stout horizontal branches.

Flower: Flowers pale yellow, 1.2-1.5 cm long, open flowers not overtopping buds of the inflorescence.

Seed: Rape seed image.

Stem: Stems of rape are erect, much-branched, up to 1.5 m tall, often purple toward base.

Leaf: Rape has leaves that are 4 to 12 inches (10-30 cm) long, slick, and generally lobed. They are glaucous, the lower ones lyrate-pinnatifid or lobed, with petioles 4 to 12 inches (10-30 cm long), glabrous or with a few bristly hairs, upper stem leaves lanceolate, sessile, clasping, more or less entire.

Root: Rape has a thin taproot system that, in contrast to turnips, cannot be harvested by grazing animals. This root system supports an erect, succulent, and highly nutritious foliage that can be grazed and allowed to regrow and grazed again.

Physiology and growth period:


Rape is 70% self-pollinating and 30% cross-pollinated. Even if wind and insects are absent, seed are still produced. Yield increases with honeybees. Competes with alfalfa and clover for insect pollination.

Quality/anti-quality factors:


Irritant poisoning of stock can occur with acute or hemorrhagic gastroenteritis. Rape seed, containing the goitrogenic L-5-vinyl-2-thiooxazolidone, can produce goiter in animals consuming modest quantities. Rape has been incriminated in several poisoning syndromes, i.e. respiratory, digestive, nervous, and urinary.



Suitability zones:

Rape is a biennial leafy forage crop grown mostly in cool northern parts of Europe, Canada, and the United States. Distributed throughout temperate regions.



Quantitiative Table:

Max Temp (C)
Min Temp (C)
Precip (mm)
Soil pH Soil Drainage
Soil Salinity
Low High Low High Low High Low High Low High Low High
Well Adapted

Climate: Rape is grown throughout temperate regions. (Need high temps/low temps, etc!!)

Soils: Waterlogged soil conditions are not suitable for Rape.

Grazing Management: Rape is sometimes chopped and hand-fed in order to reduce waste associated with trampling by livestock. Waste can also be reduced if pastures are cross-fenced and the grazing period limited to a few hours each day. Because of its rapid growth rate, rape can be seeded in an emergency and within 8 to 10 weeks will provide excellent quality pasture. Annual ryegrass, when planted with rape, adds firmness to the pasture because of its extensive fibrous root system. Rape can be grazed the entire growing season. Rotational grazing to keep forage between 4 and 12 inches will maintain a good quality of pasture throughout the year.

Turf Management:

Pests: Diseases:

Pests: Insects:

Pests: Nematodes:


Forage rape cultivars are classified as either giant or dwarf types. Both are distinct from oilseed rape and canola, although they are the same species. Giant types produce tall, upright growth with multiple stems, while dwarf types are shorter and more highly branched. Rape forage is succulent and similar in quality to other brassicas. 'Dwarf Essex', 'Rangi', 'Winfred', and 'Emerald' are cultivars that have performed well in US studies.


Vendors will not be part of the "beneficial species white papers."

See the Forage Information System variety database for a listing of vendors.


Fall plowing and preparation of a good firm seedbed is desirable as rape seeds are small. Cultipacking before seeding make a firm even seedbed. Germination must be fast with uniform emergence for the crop to get ahead of the weeds. Seed of Polish and Argentine types germinate readily when moisture and temperature conditions are suitable.

Rape may be seeded in early spring for a summer crop, in the summer for a fall crop, or in early fall for winter grazing. Soil should be firm and moist to encourage rapid development of young seedlings. Early sowings give higher yields, but crop is more susceptible when emerging, 24 F (-4 C) either killing or injuring seedlings, where as 28 F (-2 C) has no affect when one month old. Sowing in late April or early May is best in northern areas; sowing as late as June or early July give rather good results. Rape may be planted after grains, flax, corn, potatoes, sugar beets or fallow, but not after rape, mustards or sunflowers.

Seeding rate:

Seed rate and spacing of rows varies in different areas. Sow seed with a grain drill, in rows 11-15 inches (30-40 cm) apart. Because seed are so small, it is recommended to mix 50-50 with cracked grain, so as to spread out the rape seed; for a 9 lbs/acre (10 kg/ha) rate, calibrate the drill for 18 lbs/acre (20 kg/ha) of mixture.

(another source)
Rape is planted at a rate of 2 to 3 lbs/acre (2.2-3.4 kg/ha) when planted in rows or 4 to 5 lbs/acre (4.5-5.6 kg/ha) when broadcast.

Seeding depth:

If drilled, plant seed 1/2 inch (1.3 cm) deep or less for good establishment.

Fertilization and liming:

As a member of the Cruciferae family, rape requires relatively large quantities of sulfur for good growth. Apply at least 20 lbs/acre (22 kg/ha) of sulfur before planting or as a spring top dressing if fall planted. Summer or fall plantings should receive 50 lbs/acre (56 kg/ha) of N with an additional 50 lbs (56 kg) of N applied in spring. Apply phosphorus and potassium as needed.


Rape is used for pasture and silage.

Seed crop:


Rape is planted almost exclusively for temporary pasture, although it may be used for silage. It frequently is seeded alone for pasture, but mixing oats or annual ryegrass with rape will provide somewhat earlier grazing. Feed quality of rape is very good, and pasture will compare favorably with alfalfa.

Erosion Control/Conservation:

Wildlife habitat and feed:


Economic value:


If this info will be used, I will then go through and do the conversions.
Seed yields vary from 900 to 3,000 kg/ha; in North Africa it may be only 300-350 kg/ha. Rapeseed contain an average of 40% oil on a dry matter basis. Rapeseed is capturing an increasing share of world edible oilseed market, competing with soybeans, peanuts, safflower, and sunflower seed; in 1970 it was about 5% of the market, and expected to increase about 4.7% by 1980. Rapeseed oil production in 1970 was 1.7 million tons, priced at $293/MT. Rape is the most important oil seed crop in Western Europe, and Canada is encouraging more production. Almost all Canada's oil is exported. World production of rapeseed oil is about 5 million tons. In April 1972, rapeseed oil was trading at $1.23 per kg.


Soil and water conservation:




David B. Hannaway and Christina Larson, Oregon State University

Document creation:

4 June 2004

Last update:

15 July 2004


Review date: