Canola is the name given to the nutritionally enhanced seed, oil and meal produced by the conventional genetic modification of Argentine and Polish type rapeseed (Brassica napus L. and B. rapa L., respectively), and more recently tame mustard, B. juncea (L.) Czern. Although rapeseed and tame mustard were ancient oilseed crops of Asia and the Indian subcontinent, they are a recent introduction to Canada. Development of the Canadian rapeseed/canola crop is frequently referred to as a Cinderella story. The crop has undergone a great metamorphosis in nutritional quality and productivity since it was first grown on a few acres in 1942 as a World War II emergency measure. At that time rapeseed oil was considered an essential lubricant for steam engines, since it clings to water- and steam-washed surfaces better that any other oil. As the war cut off all supplies from Europe and Asia and all trains and ships of the time were steam-powered, Canada was asked to undertake rapeseed production. Seed of B. napus was imported from Argentina, and an immigrant farmer from Poland provided the original B. rapa seed; thus the common names, Argentine and Polish, came into common use.
Both species proved to be well adapted to the prairie climate and required only slight modifications to existing grain growing and handling systems. Under a guaranteed price support program the crop area expanded. However, the crop almost disappeared in 1950 because of the rapid conversion from steam to diesel power and the elimination of the support price. Fortunately, Canadian entrepreneurs sought and established new markets, first in Europe and then in Japan.
From the outset researchers realized that oilseed rape could become a major source of edible oil for Canada, which until that time had to import about 90% of its edible oil needs. However, two characteristics limited the domestic market for rapeseed oil and meal. First, the fatty acids which constitute some 98% of a vegetable oil differed from other vegetable oils in having a high proportion of long carbon-chain fatty acids called eicosenoic and erucic. These fatty acids were determined to be nutritionally undesirable. Second, the seed and meal contained high concentrations of anti-nutritional sulfur compounds called glucosinolates. Although this family of compounds imparts the desired flavour to related vegetables such as cabbage, radishes and mustard, when such high concentrations as are found in rapeseed meal are fed to swine and poultry, growth and feed efficiency are adversely affected.
To solve these problems, fast and accurate methods of detection and measurement of the offending compounds were needed. Chemists at the National Research Council’s Saskatoon laboratory developed the necessary methods, and plant breeders at the AAFC Research Centre in Saskatoon and the University of Manitoba applied them in their successful search of the world’s rapeseed germplasm for plants with low levels of the undesirable compounds. Additional plant-breeding work produced the first low erucic varieties, Oro (B. napus) and Span (B. rapa), and later the first varieties with both low erucic and low glucosinolate, Tower (B. napus) and Candle (B. rapa). The first tame mustard variety (B. juncea) with canola quality was grown in 2003.
The development of the low erucic, low glucosinolate varieties and their rapid adoption by producers and the industry greatly expanded both the domestic and export markets for the seed, oil and meal. A new name was required to distinguish the superior nutritional quality of the “double low” materials from the old rapeseed, and a committee of the then Rapeseed Association proposed the name “canola,” derived from “can” for Canada and “ola” because it sounded like oil. Canola varieties in Saskatchewan have a growing season similar to wheat and grow about 1–1.5 m tall. The B. rapa species, because it matures ten to fourteen days earlier, was initially grown on the greatest area; but with the introduction of effective herbicides, the later but higher yielding B. napus species now dominates. Each canola flower has four bright yellow petals, and upon fertilization by insects and wind a pod develops with fifteen to forty small round seeds arranged in two rows. Ripe seeds may be black, brown or yellow, and contain 41% to 44% oil and 36% to 40% high-quality protein in the oil-free meal.
Canada’s success is reflected in its production record. In 1951 there were only 2,600 ha of rapeseed planted in Saskatchewan; by 1960 there were 220,000 ha. Canola peaked in 1994, when 2.6 million ha were planted—generating for the first time a million- dollar canola crop.
R. Keith Downey