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Planning for a Successful Winter Wheat Crop

Planning for a Successful Winter Wheat Crop

Seeding

The ideal seeding window for winter wheat in Manitoba is early to mid-September. In Northern regions of the province the window is shorter, and farmers should aim to have their seed in the ground by September 15th. In Southern MB, the end of the ideal window is around September 21st. Seeding early promotes vigorous plant growth and improves the chance of winter survival. Wheat plants that begin winter with three leaves tend to have healthy, well-developed crowns.

Ideally, farmers should target a plant stand of 30-35 plants per square foot.

Seedling survival rate of 0.70 us used to account for germination and emergence, as well as the impact of winter survival.

In the fall, many fields are depleted of soil moisture from the recently harvested crop. Winter wheat should be seeded shallow (0.5-1 inch) to take advantage of fall rains.

Field Selection

It’s important to seed your winter wheat crop into standing stubble, as it will help trap snow to insulate the crown from harsh winter temperatures. For optimal winter survival, stubble should hold 4 inches of snow. Canola, barley, oat and flax stubble all have great snow trapping capability. Bean, lentil, potato and pea stubble have poor snow trapping ability. Wheat straw is not recommended due to disease concerns.

Variety

The most important factor to consider when selecting a variety is winter hardiness. Most winter wheat varieties registered in Canada are rated between good to excellent in this category. The next factor to consider is the variety’s disease resistance package. Emerson offers genetic resistance to Fusarium Head Blight. Yield potential should also be considered. See more at https://www.seedmb.ca/. Finally, in areas with high-moisture, lodging resistance is an important consideration. CDC Falcon has been a popular variety in areas that struggle with lodging.

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Fertility

Nitrogen: 80-120 lb/ac. If broadcasting ammonium nitrate (34-0-0), it’s recommended that fertilizer is applied in spring as early as field conditions will allow.

Phosphate: 30-40 lbs/ac. Place all P in the seed row. Inadequate P levels can reduce winter survival.

Potassium: 15-30 lbs/ac on sandy or organic soils.

Sulphur: 15 lbs/ac of sulphate sulphur only when sulphur levels are low.

For more information on fertility recommendations in MB, click here.

It’s also important to note that any field operations that break down stubble (such as fall fertilizer application) can negatively impact snow trapping potential. If there is any concern that you may not be able to get into the field in the spring for a split N application, it is better to give your winter wheat it’s full fertility regiment at planting, as long as it’s not all with the seed.

Additional Resources

Western Winter Wheat Initiative: General Planning

The Growing Point: Winter Wheat- Wheat to consider for a successful crop

Government of Manitoba: Winter Wheat- Production and Management

Common Questions

Q: I’d like to seed my winter wheat into barley stubble as my canola is late this year, what should I be taking into consideration?

A: There are a couple things to keep in mind when planning to seed your winter wheat into cereal stubble.

  1. Seeding issues. This used to be more of a concern due to the amount to straw and chaff cereals produce. However, newer combines do a better job and chopping and spreading residue, and many farmers have had good results seeding their winter wheat into barley stubble.
  2. Diseases. Of course, seeding a cereal into cereal residue can cause disease issues. Many of these concerns can be mitigated with use of seed treatments and fungicides. However, wheat streak mosaic is a viral disease transmitted by leaf curl mite, which requires a green (living) host to survive. If winter wheat establishes where the previous cereal crop was infected, and the previous crop still has green tissue, a “green bridge” is created that allows the mite to move from the previous crop to the winter wheat. Since there is no chemical control, it is best to allow 7-10 days between the dry down of the previous cereal crop and emergence of the winter wheat crop. There are also winter wheat varieties such as Elevate that have good resistance to wheat curl mite.
Q: Last year I side banded ESN in the fall and put additional UAN on as soon as I could in the spring. What are your thoughts on putting ESN with the seed?

A: There is a risk of injury when you place any fertilizer with the seed. This year, some unexpected injury was observed with ESN even though research out of Alberta has shown ESN to be up to three times safer that urea. See the chart below to come up with a “safe rate”. Keep in mind that under dry conditions and narrow row openers, risk of injury may still be high. In general, if you have the equipment, it is likely best to stick with the safe side-banded option.


Table 1. Rates of urea nitrogen (lb N/ac) safely applied with cereal and canola seed if seedbed soil moisture is good to excellent. Where seedbed moisture is low or when weather is hot and windy, reduce these rates by approximately 50 per cent


Width of spread varies with air flow, soil type, moisture level, amount of surface crop residue and other soil conditions, so it must be checked under field conditions.

Some openers give less than 1” spread. Urea should not be applied with the seed on light soils when a double disc opener is being used.

* SBU, seedbed utilization, is the amount of the seedbed over which the fertilizer has been spread. Thus, it is a reflection of the relative concentration of fertilizer. SBU (%) is the width of spread, divided by the row spacing, multiplied by 100. For example, if the seeding implement has a 6” spacing and spreads the seed and fertilizer over 2”, the SBU would be 33 per cent (2/6 X 100 = 33). The higher the SBU, the more fertilizer that can be safely spread with the seed. Although some openers spread the seed and fertilizer vertically, SBU does not take this into account since it is generally recognized that all seed should be placed at an even depth for even germination and emergence.


Article written by Mallorie Lewarne, Agronomy Extension Specialist- Cereal Crops with Manitoba Crop Alliance

Special thanks to Ken Gross, Ducks Unlimited Canada, and John Heard, Manitoba Agriculture and Resource Development, for their expertise on these topics.