ISSUE 1   May 13, 2010

DEALING WITH SPRING WHEAT VOLUNTEERS THAT SURVIVED THE WINTER

For the first time since my arrival in North Dakota (the fall of 2002), substantial numbers of volunteer spring wheat that emerged in the fall survived the winter. Reports suggest winter survival was not limited to just one or two "hardy" varieties; it appears that in areas of the state where this phenomenon can be observed, most spring wheat varieties survived. Durum volunteers were also found in some regions of the state as well as the odd plant of barley. Environmental conditions were obviously ideal for the survival of these volunteers. Perhaps the warm November temperatures coupled with early snow cover that insulated the emerged plants throughout the coldest winter months were the contributing factors.

There are several reasons that volunteer spring wheat can be problematic to growers this spring. First, if the volunteers established in a winter wheat crop like they did in our winter wheat experimental plots (see photo), the difference in maturity and plant height between the winter and spring wheat cultivars may cause problems at harvest. Furthermore, a mixture of spring and winter wheat may result in the harvested grain being classified as "mixed", which will reduce its market value. Unfortunately, there is no herbicide or management practice that can selectively control spring wheat volunteers in winter wheat. Secondly, spring wheat volunteers that were infected with the Wheat Streak Mosaic virus (WSMV), will be viruliferous this spring and have potential for being a source of WSMV contamination for spring planted cereals in the same or adjacent fields. When spring wheat volunteers are known to be infected with WSM, no susceptible cereal crop should be planted until there is a break of at least two weeks between the death of the volunteers and the emergence of the planted crop. The breaking of the "green bridge" that is so important in managing WSMV in winter wheat, also applies to spring sown crops this year if WSMV is present in the volunteers. Just because spring wheat volunteers survived the winter, however, does not necessarily mean that they will be infected with WSMV. No spring wheat samples tested this spring have been found to contain the WSMV. Nevertheless, there have been credible reports that spring wheat volunteers have been observed with WSMV. Additional information on WSMV can be obtained from the following extension publication from Nebraska. www.ianrpubs.unl.edu/epublic/live/ec1871/build/ec1871.pdf.


Volunteer spring wheat infesting winter
wheat plots in Prosper, ND. Volunteers
were particularly numerous on the tractor’s
wheel tracks.

Joel Ransom
NDSU Extension Agronomist
joel.ransom@ndsu.edu

 

STRATEGIES FOR OPTIMIZING CANOLA 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

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.
  • 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 through mid May. Research shows that yield potential may be reduced with delayed planting. This mostly is a result of the high temperatures during flowering. Hot conditions during flowering shorten the time the flower will receive pollen, as well as the duration of pollen release and viability. This can decrease the number of pods on the plant and 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. For more detailed information about fertilization, go to www.ag.ndsu.edu/pubs/plantsci/soilfert/sf1122.pdf .
  • Control weeds as early as possible because a lot of competition early during the growing season can reduce yields very quickly.
  • 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.
  • Hans Kandel
    Extension Agronomist broadleaf crops
    hans.kandel@ndsu.edu


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