The name "Canola" is a trademark of the oilseed rape first developed in Canada during WW II. The Canadians wanted to find a substitute for petroleum-based lubricants, worked with rapeseed oil and bred it to eliminate unpalatable fatty acids and proteins from the oil and meal. They needed a new name for their hybrids, hence the name Canadian Oil Low Acid: Canola. Canola and rapeseed are produced mainly in Canada and Western Europe. Production in the U.S. is currently concentrated in the upper Midwest in the Dakotas, however canola has been grown in many states across the U.S. on a limited basis.
Yields of canola vary with location, but based on performance trials in the mid-Atlantic region, yields of 2000-3500 pounds of oilseed per acre should be possible.
Uses and Potential Uses
Canola is widely grown for its high quality oil for human consumption. Canola contains approximately 40 to 42% oil, compared with soybeans at 18 to 20% oil. Canola meal is an excellent protein supplement in cattle rations and averages about 35% crude protein. Canola meal is a common supplement in the dairy industry and can provide higher levels of some amino acids, like methionine, than soybean meal.
Canola and rapeseed oils also make good feedstocks for the biodiesel and the biolubricant industry. Worldwide, rapeseed is the most common feedstock used for biodiesel. Oil yields from canola or rapeseed production will be nearly twice that of soybeans per acre at the same grain yield levels.
Canola also can be a beneficial rotational or winter cover crop. It produces a large amount of biomass and its deep taproot system can help alleviate soil compaction and improve soil tilth. Often canola will follow a winter or spring cereal in rotation. In some areas soybeans can be double cropped following canola harvest.
Canola and rapeseed varieties are available in both winter and spring types. The winter hardiness of the winter types has been a production issue in the past, but it is improving. Compared to other small grains, it is similar to winter barley in winter hardiness. In most areas of Pennsylvania, it should have acceptable winter hardiness; a strong fall stand could be reduced to 30% during the winter before yields would fall below 90% of optimum. In the Zone 1 regions of the northern tier without good snow cover, spring types should probably be considered.
Since canola is not widely grown in Pennsylvania, variety selection is very limited. Numerous winter and spring varieties are available, but none have been extensively tested in Pennsylvania. A national winter canola test is conducted throughout the country, with sites in Ohio and Virginia, which can provide some performance information and sources of seeds. This test is coordinated by Kansas State University and is available on-line. Spring and some winter varieties are available through several of the major seed companies that service the major canola producing areas. Transgenic spring canola varieties are available that are resistant to various herbicides such as Roundup and Liberty.
Before growing any rapeseed/canola, check to make sure the variety is approved for the market. Never grow rapeseed and canola together because cross pollination will contaminate the seeds of both.
Soil and Climate Adaptation
Canola and rapeseed are adapted to well drained soils that range from sandy to clay loam in texture. Avoid poorly drained or heavy clay soils where heaving or winterkill could be a problem. Avoid soils that have a tendency to crust, as seed germination will be impaired. Also, avoid low lying soils where white mold can be a problem in soybeans or green beans, as canola is susceptible to this disease as well. Canola can also be grazed by turkeys and deer, and can tolerate some grazing in the fall, but fields with a history of severe wildlife damage are not likely to be ideal.
Canola can be planted no-till or with a conventional seedbed preparation into soils of pH 6.0-7.0. It needs a fairly firm seedbed. In high residue no-till situations, slugs can be a problem as they are with other crops. The seeding rate for canola is about 4- 5 pounds per acre. In grain drills, use the small seed box and calibrate carefully to avoid overseeding. Seed depth should be about 1⁄2 inch and row width, 7-15 inches. A stand of plants with a density of 6 to 8 plants per square foot is ideal. Canola can branch considerably and fill in stands that have some winter kill. Stands should be assessed in the spring; consider keeping canola stands if the plant density is in the range of 2 to 5 plants/square foot.
Winter canola should be planted in late summer to ensure adequate growth before winter. Ideally plants should have 6 leaves and a taproot the size of a pencil before the first killing frost. In central Pennsylvania, seeding from Sept 1 to 15 is a good target. In longer season areas in the southern part of the state, planting can continue through the end of September.
Spring canola should be planted in early to mid April. Planting as early as possible when the soil has warmed to 37-40 deg F helps the crop avoid heat and drought injury that can occur during June and July. It also allows the young plants to become established before flea beetles emerge. The optimal day growing temperature is 70-75 degrees. The temperature range for growth is 50-85 degrees. Canola is especially sensitive to heat stress during flowering and early pod filling. Especially with spring canola, it is important to recognize the timing of flowering to minimize exposure to heat.
Seed companies' fact sheets commonly have days to bloom and days to beginning pod maturation. Below is a summary of canola growth stages:
Seeding and Plant Emergence
Plant to ensure good seed to soil contact. The seedling cotyledons emerge 4-15 days after seeding, depending on soil moisture.
True leaves emerge singly, with a total of 8 or more leaves arranged in a rosette near the ground.
Winter canola requires vernalization to achieve stem elongation. Developing the maximum stem length overlaps the flowering period and is reached as flowering wanes. Plant height depends on cultural conditions and genetics. Spring canola generally begins elongation at the 6-leaf stage.
Flowering starts with the opening of the flowers, from the bottom of the inflorescence up to the top. If leaf area is lost (due to hail, animal feeding, etc) at this stage, yield can be recovered by inflorescences developing from the leaf axils along the elongated stem. However, heat stress at the flowering and early pod fill will decrease yield substantially; days above 90°F interfere with pod set. Moisture stress causes seed oil content to drop while protein content increases. Seed size and number of pods are also unfavorably affected.
Pods are filled in the same order they were pollinated, from the bottom of the inflorescence to the top. Leaves will senesce as pods mature. When about 30% of the pods have turned color from green to yellow, the plant is near physiological maturity.
In general, fertilizer recommendations for winter canola are similar to winter wheat. An N-P-K blend broadcast in the fall can help with fall establishment and is essential to a strong start in the spring. An application of 25-50 pounds of phosphate and potash should be adequate on soils that are in the optimum range for these nutrients. This is approximately the nutrient removal by the canola grain. Nitrogen recommendations in the fall vary but most suggest 20-30 pounds per acre, applied as part of a starter fertilizer.
In the spring, winter canola is top dressed similar to winter wheat. Nitrogen fertilizer recommendations are higher than for wheat, with optimum yields occurring with application of 80-100 lbs of N per ton of expected yield per acre. Uptake of sulfur in canola is greater than in wheat, so there many be some need for this nutrient, as it may allow more efficient use of nitrogen. As with wheat, responses to sulfur are somewhat inconsistent, with the most response found in soils low in organic matter or sandy soils. Where warranted, consider an application of 20 to 30 pounds of S per acre.
In spring canola, apply fertilizer at seeding, taking care to keep the fertilizer placement away from the seed. N fertilization can be less than for winter canola because spring canola lacks fall-applied N need and its yields are generally lower than winter canola.
Integrated Pest Management and Canola
Ripening and harvest
Canola can be straight combined or swathed and combined. Several factors make combining a problem: 1) small seed size 2) uneven ripening up and down the plant in some varieties and 3) shattering if the harvest is left until too late. The crop can be combined when the pods are uniformly tan in color and the seeds are firm, dark and shiny… With large-seeded B. napus hybrids, use care in threshing because the seeds are prone to crack and this will lower the seed quality.
Observe the labeled rotational intervals when planting canola into fields treated with: Accent, 10 months; Equip, 18 mo.; Atrazine, 10-18 mo.; Finesse, 14-36 mo.; Hornet, 26 mo.; Maverick, 22 mo.; Peak, 22 mo.; Harmony Extra, 2 mo., Permit, 15 mo.; Priority, 15 mo.; and Spirit, 10 mo. For other herbicides, consult their labels.
Selecting a well-drained field is essential to growing productive canola. Canola in saturated soils will suffer more winter kill losses and is much slower to resume growth in the spring.
In general, insect pests have not been a major problem on canola in Pennsylvania, but insects which are attracted to other crucifers are sometimes pests, but usually do not affect yield. Ontario producers report significant problems on occasion with the crucifer flea beetle, which damages young seedlings when the larvae hatch out in late spring/early summer. It can be controlled with foliar insecticide or by use of a seed treatment such as Helix or Prosper.
A healthy stand of canola generally has good disease resistance. Black leg disease and white mold caused by Sclerotinia cause the most problems. These two fungal diseases are the primary reasons for allowing 3-4 years to elapse before replanting canola in the same field. Canola seed can be treated at planting to control these diseases with products like Prosper or Helix Xtra. These products may be less effective under dry spring conditions.
Currently, canola has no established market in Pennsylvania, although canola markets have been operating in Canada and North Dakota for some time. Because of the high yield and quality of its oil as food, fuel and feed, the canola market should develop in the US. Presently, growers should forward contract their canola production and consider the transportation cost to the elevator. Also, before producing significant amounts of canola, producers should compare canola production profitability to crops like soybeans or wheat. An Enterprise Budget for winter canola appears below to aid in your analysis. At a market price of $8.00/bu, production costs are covered at a yield of 26 bushels/acre in this budget.
Figure 1. Estimated Canola Production Costs and Receipts.
|Receipts - Canola||bu||8.00||50.000||400.00|
|Custom apply lime||ton||30.00||0.500||15.00|
|Soil test results||acre||100||1.000||1.00|
|Hrebicide - Treflan||gal||25.60||0.243||6.22|
|Seed - Canoloa Seed||lb||3.00||5.000||15.00|
|Diesel Fuel - tractor||gal||2.25||5.170||11.63|
|Repair and Maintenance|
|Interest on Op. Cap.||acre||8.80||1.000||8.80|
|Total Variable Cost||189.48|
|Returns Above Variable Cost||210.52|
|Total Fixed Cost||16.95|
|Returns to Land and Management||193.57|
For Further Reading
- Canola factsheet from the Alternative Crops Manual.
- A guide to canola production published by the Ontario Ministry of Agriculture, Food and Rural Affairs.
- Canola production recommendations from Ohio State University Extension, Columbus, Ohio.
- "Great Plains Canola Production Handbook", 2006, developed by Oklahoma State, Kansas State and U. of Nebraska. Very detailed, especially dryland practice.
- Canola, an Emerging Oilseed Alternative," The Jefferson Institute, Columbia, MO, a non-profit research and education center supporting crop diversification.
- Canola Growers Manual, Canola Council of Canada, 2003. This is a very comprehensive guide on canola, but is written for growing spring canola on the Canadian prairies, and so should be adjusted for growing conditions in the Northeast United States.
Prepared by Mary Carol Frier and Greg W. Roth, Penn State