By Dr. Michael Boland, content specialist, Ag Marketing Resource Center, Kansas State University.
Reviewed September 2004.
Overview
Rapeseed, a large winter or spring annual oil crop in the Brassica family, is related to mustard, cabbage, broccoli, cauliflower and turnip. Rapeseed plants grow from three to five feet tall and have yellow flowers with four petals. Rapeseed has a deep taproot and a fibrous, near-surface root system.
Rapeseed is primarily grown for its oil and meal. However, it is also beneficial as a cover crop. It provides good soil cover over winter to prevent soil erosion, produces large amounts of biomass, suppresses weeds and can improve soil tilth with its root system. Winter rapeseed can also be grazed by livestock during the fall growth period.
There is often confusion between the use of the terms “canola” and “rapeseed.” Rapeseed is the traditional name for the group of oilseed crops in the Brassicaceae family. It can be divided into two types — industrial rapeseed or canola. Visually, the seeds of the two types are identical. The distinguishing difference between the two types is their individual chemical or fatty acid profiles. Generally, canola refers to the edible oil crop that is characterized by low erucic acid (less than 2 percent). “Industrial rapeseed” refers to any rapeseed with a high content (at least 45 percent) of erucic acid in the oil. This profile will focus on industrial rapeseed.
Traditionally, industrial rapeseed is produced for birdseed and oil for industrial purposes. Industrial varieties of rapeseed are used for non-edible purposes such as lubricants, hydraulic fluids and plastics. High-erucic-acid rapeseed (HEAR) oil is especially useful where high heat stability is required. One of the primary markets for high-erucic-acid oils is erucamide. Erucamide has been used for decades by plastic film manufacturers for use in bread wrappers and garbage bags and is preferred over cheaper alternatives for its production properties.
Rapeseed grows well on a wide variety of well-drained soils, prefers a pH between 5.5 and 8.3 and is moderately tolerant of saline soils. Industrial rapeseed has been grown in the Pacific Northwest for more than 40 years. It was also produced in the South during the late 1980s and early 1990s. Harvested acreage of industrial rapeseed has declined from 19,400 acres in 1987/1988 to 1,200 acres in 2003. Price in 2003 averaged $11/cwt.
The industry for industrial rapeseed is fairly mature. However, with increased emphasis on renewable resources and biodegradability, there is a possibility of an increased interest in raw materials such as high erucic oil. It is recommended that rapeseed for the industrial oil market be grown under contract.