Oregon State University
Washington State University
University of Idaho
Direct Seed Tillage Handbook
   Return Tillage Handbook

Chapter 8-Crops and Varieties, No.2, June-July 1985

New Rapeseed Varieties to Expand PNW Market Potential

Roger Veseth

The availability of new winter rapeseed varieties appears to be a key to greatly expanding the foreign and domestic markets for this oilseed crop. STEEP researcher Dick Auld, University of Idaho plant breeder at Moscow, planned to submit two new varieties of winter rapeseed for release in 1986 for two different markets. The new varieties were "Cascade," an edible oil variety and ''Bridger, " an industrial oil variety. In addition, the meal by-product of the varieties makes a highly nutritious livestock feed. Winter rapeseed is very effective in controlling soil erosion over the winter and provides an excellent rotational crop with cereals.

Auld and other researchers have been working to develop winter rapeseed varieties and management practices over the past 9 years. Winter rapeseed has proven to be an excellent rotational crop as well as a cash crop with yields in the 2,200 to 3,500 pounds-per-acre range in northern Idaho. Growers have often reported that their highest winter wheat yields follow a crop of winter rapeseed. One reason for this could be the vigorous taproot system of winter rapeseed which is effective in breaking up plow pans. This improves drainage, which creates a less favorable environment for root diseases. It also increases soil water infiltration and storage, as well as the effective rooting depth for the following crop. The breakdown of winter rape residue may also release compounds that retard growth of fungal diseases that attack wheat. Since winter rapeseed is planted on summer fallow in early August it also lengthens the rotation, which further helps reduce wheat disease problems.

With the early planting, rapeseed produces prolific vegetative growth by late fall and provides excellent cover for soil erosion control. Auld states there is essentially zero erosion over the winter with a well-established stand. He encourages growers to consider winter rapeseed to protect set-aside ground which is not in crop. Winter rapeseed performs well in the 16-to 20-inch precipitation zone and is adapted to a wide range of soil types, although it will not tolerate waterlogged soils.

Winter rapeseed varieties grown in the U.S. over the past 30 years have had a limited market. Most of the seed is used for birdseed or industrial oil and not human consumption. The reason it is not used for human consumption is the chemical composition of the oil. Most winter rapeseed varieties contain relatively high levels of erucic acid. Erucic acid makes oil good for industrial uses but has been reported to cause heart lesions and disrupt other physiological processes in laboratory animals if used as an edible oil. Because of the high erucic acid content, the Food and Drug Administration (FDA) had limited the use of rapeseed oil for human consumption to 2 percent in peanut butter and 4 percent in shortening. Present varieties of winter rapeseed also have high glucosinolate content, which restricts the market potential for winter rapeseed meal as a high protein animal feed. The compound breaks down into toxic substances that make the otherwise highly nutritious meal unsuitable for livestock consumption.

Two changes have begun to open the door to the edible rapeseed oil markets. Starting in January of this year, the FDA allowed the consumption of low erucic acid rapeseed oil in domestic products (except for infant formulas). This is something the Canadian government has been pushing for, to increase sales of low erucic acid Canadian spring rapeseed in the U.S. The second change is the upcoming release of "Cascade," Auld's low erucic acid and low glucosinolate edible oil variety of winter rapeseed. The quality of oil from this new variety is comparable to the best Canadian spring rapeseed varieties.

Rapeseed oil now ranks third in the world consumption of edible oils, and the U.S. portion of the production is near zero. Canada, China, India and northern Europe produce 90 percent of the edible rapeseed oil. Japan buys 80 percent of the world export of edible rapeseed which accounts for 37 percent of its edible oil imports, while soybeans provide 48 percent. Most of Japan's edible rapeseed is imported from Canada which produces spring rapeseed with low levels of erucic acid and glucosinolates.

Currently, Canada produces 1.4 million metric tons of spring rapeseed valued at $370 million. Since 1960, rapeseed acreage in Canada has grown from 20,000 acres to over 2 million acres while U.S. acreage has remained constant at 3,000 to 5,000 acres. U.S. rapeseed is grown primarily in northern Idaho. Auld feels that edible oil varieties of winter rapeseed such as "Cascade" will make the U.S. competitive with Canadian spring rapeseed in the world export market. Winter rapeseed grown in northern Idaho contains 42 to 46 percent oil compared to Canadian spring rapeseed at 40 to 42 percent oil, and it also matures a month earlier.

New edible oil winter rapeseed varieties would also compete with oil from soybean and other crops. For example, rapeseed contains over 40 percent oil while soybeans are about 17 percent oil. This is an important difference in shipping costs to a Japanese oilseed crusher importing from the U.S. They have to crush 7,500 pounds of soybeans to get the same amount of oil they would get from crushing 2,800 pounds of rapeseed. The cost of 7,500 pounds of soybeans is also about twice that of 2,800 pounds of rapeseed. Besides being a more efficient and economical oil for processors, winter rapeseed is also an attractive crop option for Northwest growers. Through the present limited markets, winter rapeseed is capable of producing as much revenue as winter wheat in many production areas, with less production costs than conventional cereal crops.

Besides the large market potential for new edible rapeseed oil varieties, the ''Bridger" variety, with a high erucic acid content, could help to expand the industrial oil market. Rapeseed oil with high erucic acid content is used in high-grade industrial lubricants, as well as plastics, particularly low friction plastics. ''Bridger" is also low in glucosinolates, allowing the meal by-product to be used as a livestock feed.

The use of vegetable oils as diesel fuel substitutes is of increasing interest in recent years with rising oil prices and the possibility of shortages. Auld is attempting to develop a variety that is specifically adapted as a diesel fuel substitute. Research by Charles Peterson, University of Idaho agricultural engineer and STEEP researcher, has shown that rapeseed oil provides about as much power and efficiency as diesel fuel. Over the past 2 years a Mitsubishi tractor has operated continuously on a 50:50 fuel mixture of diesel and rapeseed oil with no measurable reduction in power or compression. This rapeseed oil/diesel substitute research program has been directed at developing systems that growers could use to process rapeseed on the farm for oil and also use the meal for livestock feed. In times of critical fuel shortages, rapeseed could be crushed on the farm to provide a source of emergency diesel fuel.

An excellent production management guide on winter rapeseed is available from the University of Idaho. Winter Rape Production Practices in Northern Idaho, Agricultural Experiment Station Bulletin 634, summarizes 8 years of research by Auld and other STEEP researchers: Glen Murray, plant physiologist; Larry O'Keeffe, entomologist; and Dorm Thin, weed scientist. This guide covers a broad range of topics including crop characteristics, variety trials, cultural practices, fertilization, weed, disease and insect management and market potential. Contact the Agricultural Extension Agent in your county to obtain a copy of this publication.

Auld and his associates are convinced of the potential of winter rapeseed as an alternative crop for the Northwest. He would like to see 1 million acres of winter rapeseed in production by the end of the decade and feels that markets can be developed to support this level of production. The new varieties to be released in 1986 promise to greatly expand economic crop options and markets for the region. Winter rapeseed has also proven to be an excellent rotational crop and an effective soil conservation tool.


Contact us: Hans Kok, (208)885-5971 | Accessibility | Copyright | Policies | WebStats | STEEP Acknowledgement
Hans Kok, WSU/UI Extension Conservation Tillage Specialist, UI Ag Science 231, PO Box 442339, Moscow, ID 83844 USA
Redesigned by Leila Styer, CAHE Computer Resource Unit; Maintained by Debbie Marsh, Dept. of Crop & Soil Sciences, WSU