The optimum planting date windows are between September 1st and the 15th in the area north of I-94, between September 10th and the 30th south of I-94, and between September 20th and October 10th in the part of the state south of I-90. (Photo Source: Flickr/Clare Black. “Wheat”)
MINNEAPOLIS — We are quickly approaching the optimum time for planting winter wheat and rye in Minnesota. The optimum planting date windows are between September 1st and the 15th in the area north of I-94, between September 10th and the 30th south of I-94, and between September 20th and October 10th in the part of the state south of I-90.
Though seeds that just begin the germination process will vernalize (meet the necessary cold requirement to produce a spike in the summer), a much larger seedling typically has a better chance of overwintering and being more productive. Below are key points to establish winter wheat and rye successfully and give it the best chances to survive Minnesota’s winter.
Plant winterhardy adapted varieties
Use a winter hardy variety, especially if you are not planting into residue or you are seeding past the optimum planting window. Late planted winter wheat and rye will be smaller and more prone to winter injury, particularly if there is little snow cover over the course of the winter, and less vigorous next spring. Check the most recent University of Minnesota Variety Trials Bulletin for information about the winter hardiness of varieties currently available for planting.
Plant winter wheat into standing stubble
Risk of winterkill is greatly reduced when the crop is covered with snow during the coldest months of the year. Standing crop residues can effectively retain snow and help insulate the crop during the winter. Tall, erect flax and canola stubble work best, but any erect stubble that will retain snow is recommended. Abandoned stands of alfalfa that have been killed with glyphosate also work well. Even standing soybean stubble is capable of trapping some snow and reducing winterkill. Planting winter wheat into wheat stubble is not ideal due to the increased risk from residue-borne diseases. However, if disease management is planned, planting into wheat stubble is better than seeding into a clean-tilled field.
Calculate the correct seeding rate
An optimum stand for winter wheat and rye in the spring is 23 to 25 plants/ft2 (900,000 – 1,000,000 plants per acre). Calculate a seeding rate accordingly, knowing that a poor seedbed and planting past the optimum window will mean a higher percent stand loss and/or more winterkill. If planting is delayed or conditions exist that may delay germination and emergence, the seeding rate can be increased by about 150,000 to 200,000 seeds per acre.
Heed replant and crop rotation restrictions of previously applied herbicides
Many herbicides have soil residual activity. This means that the herbicide label will state re-cropping restrictions for sensitive crops. Follow the herbicide label restrictions and conduct a bioassay if you unsure about the risk of herbicides carry-over.
Apply phosphorus at time of planting
Phosphorus (P) fertilization can play a role in winter hardiness, especially if soil tests for P are low. Phosphorus helps develop strong roots and crown tissue, which will help the crop overwinter. The rate of P applied with the seed should be limited by the amount of nitrogen (N) in the fertilizer, since excessive N prior to freeze-up can reduce winter survival. In narrow rows, nitrogen should not exceed 15 pounds per acre with the seed, particularly if conditions are dry.
Plant 1 to 1.5 inches deep
Adequate moisture for establishing winter wheat and rye is often a concern as the soil profile is often depleted of moisture in the fall. If there is little or no moisture in the soil’s surface, planting shallow (1 to 1.5 inches deep) and waiting for rain is recommended. Furthermore, these relatively shallow planting depths allow for faster emergence when temperatures are rapidly declining.
Avoid the “Green Bridge”
Avoid fall infections of Wheat Streak Mosaic virus, Barley Yellow Dwarf virus, Hessian Fly, and/or tan spot by not planting prior to the recommended planting windows. Desiccate any volunteer wheat, barley, oats, or grassy weeds at least a week prior to planting. A pre-plant burndown application of glyphosate is an effective tool to kill any volunteer grain and grassy weeds prior to seeding into standing stubble.
Choose the correct planting date
The optimum planting date windows are between September 1st and the 15th in the area north of I-94, between September 15th and the 30th south of I-94, and between September 20th and October 10th in the part of the state south of I-90.
Consider treating seed
Use a seed treatment if you have a field history of common root rot and/or Fusarium crown rot and seed into a standing stubble of wheat, barley or oats, if the seed lot is particularly scabby, or if loose smut was noticed during the production of the seed.
— Jochum Wiersma, Jared Goplen, and Phyllis Bongard, University of Minnesota Extension
Source: University of Minnesota Extension