Sieg Snapp and Russell Freed
Crop and Soil Sciences Department
Michigan State University

There has been new interest recently in an old oilseed crop, canola. Canola was developed by Canadian plant breeders that made selections from rapeseed that had low erucic acid and glucosinolate levels – less than 2% erucic acid and less than 30 micro-moles of glucosinolate in the meal. As a member of the Brassica family, canola could be an important crop to help diversify our region’s agriculture, complement our cropping systems, and maintain a vibrant rural sector. Canola has tremendous potential to have an impact on our economic, health, environment and agricultural systems. Some of canola’s attributes are:

• High yield of value-added products (over 3000 lbs/acre).
• High quality oil: Lowest saturated fat of vegetable oils (7%) and high levels of healthy monounsaturated fats (61%) and alpha-linolenic (omega-3) acid (11%).
• New uses such as environmentally friendly bio-based oils and fuels.
• Niche market opportunities (organic/specialty oil) for non-GMO.
• Excellent soil building properties and an alternative crop that provides winter ground cover.
• Flexibility in planting time and diversification for sustainable production.

One of the challenges of producing alternative crops is identifying a secure market. There is a small and volatile organic canola market and increasing interest in growing canola as a potential component of biodiesel (In Europe there are biodiesel plants that process canola oil, but this market is not yet developed in the United States). The export and domestic demand for canola is not consistent and attention to marketing is important.

Canola will provide diversity in terms of flowers, plant residues with unique biochemical compounds and reduced host potential for many plant parasitic nematodes. Another attribute of Brassica family plants often discussed is the potential for bio-fumigation. Many Brassica species such as mustards produce chemical compounds in the roots and leaves, which have biocide effects that inhibit soil-borne diseases. If managed as a green manure crop, where green residues are chopped and incorporated, then a mustard or oilseed radish may improve the root health of subsequently grown cash crops. For more information, see the recent MSU Extension bulletin: Snapp, S.S. K. Date, K. Cichy and K. ONeil. 2006. Mustards: A Brassica Cover Crop for Michigan. Michigan State University Extension Bulletin E2956.

It is important to realize that canola grown in a crop rotation is not expected to have the same effects as a mustard grown as a green manure or cover crop. The glucosinolates have been bred out of the canola varieties; these are the plant biochemical compounds that have biofumigation effects. Also, growing a crop to maturity and removing the seed will leave older residues and roots that may have minimal effects on soil organisms compared to incorporating a fresh, green vegetative cover crop. However, canola will provide very different types of root inputs than other plant families such as legumes (soybean, dry bean) and grasses (corn, wheat, oats), and crop diversification promotes a healthy soil community.

Canola production
Canola has exacting production requirements. Soils must be well drained, and soil fertility is important in order to supply the considerable nitrogen, phosphorus and sulfur requirements of this crop. The biochemical compounds that are unique to the brassica family are a key reason why these plants require high sulfur availability. Organic sources of sulfur include elemental sulfur and gypsum. Soils will also have good sulfur supplying capacity if they are high in soil organic matter through long-term attention to following soil-building practices such as growing cover crops and adding judicial amounts of manure.

There are winter and spring varieties of canola. Generally, both can be considered to fit into diverse cropping systems throughout the Upper Midwest as these are widely adaptable to this region. Winter canola is often grown in locations where winter barley does well, and winter-seeded canola will usually produce moderately higher yields than spring canola. See information summarized by the Great Lakes Canola Association on requirements for of spring and winter canola production, below and www.agry.purdue.edu/ext/canola/varieties.htm

Wet and poorly drained soils are not suitable for production of canola and this is a primary consideration in choosing a field for canola – there should be no standing water problems. It is also important to have no wild mustard weed infestation problems.

For the seeding rate of a specific canola variety, check with the seed source. A general recommendation is to plant 5 to 7 lbs per acre with a drill used for planting small grains.

Canola has a small seed and produces a small seedling that initially may be susceptible to weed competition, so a management strategy for pre-plant and pre-emerge control of weeds is important. Once canola is established, it has a broad leaf and will suppress many weeds. Pest problems are generally minimal although there are some potential disease and insect issues that are summarized by the Great Lakes Canola Association, at http://www.agry.purdue.edu/ext/canola/. A potential problem is Western Beet Yellows virus, which has the potential to be transferred between sugar beets and canola, so do not produce canola in sugar beet-producing areas.

Canola can be combined directly by a small grain combine, at about 9 to 10 percent seed moisture. Generally, about 95 percent of the pods will have turned brown and seed in the pods will be black at maturity. Slow combine speed should be used to enhance seed cleanliness. To maintain high seed oil quality is important, and processors and market outlets should be consulted to learn of specific harvest or post-harvest storage recommendations.

Resources
The Great Lakes Canola Association has a website with excellent conventional canola production information, see http://www.agry.purdue.edu/ext/canola/

A recent guide on organic production of canola was produced in Australia. For a copy of this review, type ‘Canola’ into the search engine at: www.dpi.vic.gov.au/dpi/nreninf.nsf. Note that the organic production method described is somewhat ‘substitution’ oriented, as organic mined sources of nutrients are described and limited information is provided on building soil fertility with cover crops. It was also developed for a drier climate than the upper Midwest as the annual rainfall is about 15 inches in the region of Australia where organic canola is primarily produced.