Planning for a Successful Winter Wheat Crop
- Winter Wheat
The key to winter wheat production is planning ahead to set yourself up for success. By planning for your winter wheat crop in the spring, you can ensure your fields have suitable stubble and are ready for planting your winter wheat crop in the ideal seeding window.
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 Sept. 15. In southern Manitoba, the end of the ideal window is around Sept. 21. 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.
Farmers should generally target a plant stand of 20 to 30 plants per square foot. When calculating seeding rate, a seedling survival rate of 0.70 is used to account for germination and emergence, as well as the impact of winter survival. To calculate seeding rate in pounds per acre based on a desired plant population, use the following equation:
In the fall, many fields are depleted of soil moisture from the recently harvested crop. Winter wheat should be seeded shallow (half an inch to one inch) to take advantage of fall rains.
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 four 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.
There are many factors to consider when selecting a winter wheat variety for your operation, including winter hardiness, disease resistance, yield potential and lodging resistance. AAC Wildfire and AAC Goldrush are the two best options for winter hardiness in Manitoba and both have good seed supply in the province.
Table 1. Popular Canada Western Red Winter varieties in Manitoba. For a complete list, see the Manitoba Seed Guide.
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 nitrogen (N) application, it is better to give your winter wheat its full fertility regimen at planting, as long as it’s not all with the seed. Soil tests are usually recommended to aid in fertility decision making. If soil tests are not available, the following are general fertility recommendations:
- Nitrogen: 80 to 120 pounds per acre. If applying in the spring, N in nitrate form is the most readily available form, so dribble-banded UAN (28-0-0) is a good choice. Enhanced efficiency N (controlled release or nitrification inhibitors) can be effective if fall application is desired.
- Phosphate: 30 to 40 pounds per acre. Place all phosphorus (P) in the seed row. Inadequate P levels can reduce winter survival.
- Potassium: 15 to 30 pounds per acre on sandy or organic soils.
- Sulphur: 15 pounds per acre of sulphate sulphur, only when sulphur levels are low.
For more information on fertility recommendations in Manitoba, click here.
Western Winter Wheat Initiative
Grow Winter Wheat
Manitoba Crop Alliance
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:
- Seeding issues: This used to be more of a concern due to the amount of straw and chaff cereals produce. However, newer combines do a better job of chopping and spreading residue and many farmers have had good results seeding their winter wheat into barley stubble.
- 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 seven to 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 than 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 2. 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.
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.