Extension and Ag Research News


NDSU Offers Strategies for Optimizing Canola Yields

The use of improved, herbicide-tolerant, high-yielding varieties or hybrids contribute to higher yields.

Conditions in 2009 were very favorable for canola production, with an average yield for North Dakota of 1,840 pounds per acre. In some reports, yields ranged from 2,000 to 3,000 pounds per acre if weather conditions and excellent crop management came together.

The use of improved, herbicide-tolerant, high-yielding varieties or hybrids contributed to high yields, according to Hans Kandel, North Dakota State University Extension agronomist, and Dave Franzen, NDSU Extension soil science specialist.

Franzen and Kandel have some management suggestions for getting high canola yields:

  • Select a variety or hybrid that has a proven high-yield potential in university and company trials. Obtain data from trials from several locations in your growing region. Results from the 2009 NDSU canola variety trials can be found at http://www.ag.ndsu.edu/varietytrials/canola.
  • Field selection is important. Canola does well following small grains or fallow in a rotation. With canola in a crop rotation, there should be at least a two-cropping-year wait before canola is seeded again. Avoid crops such as sunflowers, dry beans and other sclerotinia (white mold)-sensitive crops in close rotation with canola. Select fields that are free of troublesome weed problems.
  • Plant seed with a high germination percentage and with good seedling vigor. Planting seed treated with an insecticide and fungicides for seedling protection is recommended.
  • Canola is a cool-season crop and can be seeded mid-April through early May. Research shows that yield potential may be reduced with delayed planting. This mostly is a result of the increased potential of high temperatures during flowering. Hot conditions during flowering shorten the time the flower is receptive to pollen, as well as the duration of pollen release and viability. This can decrease the number of pods that develop on the plant and the number of seeds per pod, resulting in lower canola yields.
  • Canola should be planted into a firm seedbed and at a uniform depth. The recommended seeding depths are 3/4 to 1 inch. A seeding rate of around 700,000 live seeds per acre (16 live seeds per square foot) should result in a established plant stand of 10 to 12 plants per square foot (435,000 to 522,000 plants per acre), which would be adequate for high yields. Varieties and hybrids differ in the number of seeds per pound.
  • Canola responds well to applied fertilizer. Nitrogen (N), phosphorus (P) and sulfur (S) are the key nutrients for high yields. Always have a soil test done to help you know how much to apply for high-yield goals.

Nitrogen recommendations follow a formula in which the supplemental nitrogen is the yield goal (pounds per acre) times 0.065 minus the soil nitrate in the 0- to 24-inch depth (from soil sampling). If the previous crop was a legume, an N credit can be subtracted from the N fertilizer application rate. Growers in cooler, moister areas of the state should consider a maximum 150-pounds per-acre N cap recommendation, while growers in the drier, warmer areas of the state should use the 120-pounds per-acre N rate cap (soil N plus supplemental N).

Canola does better with P fertilizer banded at seeding than broadcast. The amount of N will limit the rate of P fertilizer applied, so many successful growers have seeders that separate banded fertilizer from the seed.

The sulfur soil test is so inaccurate that S is recommended, regardless of test results. Sulfur use has the greatest returns in lower-organic-matter soils in rolling terrain, but yield increases also have been documented in heavier, higher-organic-matter soils. A soluble sulfate fertilizer, such as ammonium sulfate or gypsum, is recommended. Elemental sulfur of any kind is not recommended.

For more detailed information, go to http://www.ag.ndsu.edu/pubs/plantsci/soilfert/sf1122.pdf.

Other recommendations by Kandel and Franzen:

  • Control weeds as early as possible because a lot of competition early during the growing season can reduce yields very quickly. Herbicide-tolerant canola hybrids usually show little, if any, herbicide crop injury if the herbicide is applied according to the label. Monitor for any late-emerging weed flushes that were missed during the first herbicide application.
  • Monitor for any flea beetle or other pest problems, especially the first three weeks after seed emergence. Be prepared to apply an insecticide if the seed treatment does not hold long enough or the insect pressure is too great.
  • As the canola gets near the bud or early bloom stage, start monitoring the NDSU canola disease risk map website at www.ag.ndsu.edu/sclerotinia/ for sclerotinia stem rot (white mold) potential. Be prepared to get a fungicide applied to the crop when the sclerotinia risk map indicates a high risk for the disease.
  • Swath the canola at the optimum time to ensure maximum yield and quality. If the canola is allowed to get too ripe, shattering can be a problem and reduced yields will result. If cut too early, then green seed problems can result in discounts when the canola is sold.

Source:Hans Kandel, (701) 231-8135, hans.kandel@ndsu.edu
Source:Dave Franzen, (701) 231-8884, dave.franzen@ndsu.edu
Editor:Rich Mattern, (701) 231-6136, richard.mattern@ndsu.edu
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