NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665

August 26, 1999

Winter Wheat: a Crop with Potential

Winter wheat has the potential to be a highly productive crop in North Dakota. Advantages of winter wheat include more efficient labor and machinery use, reduced weed problems--particularly wild oat--and often a higher yield potential. But winter survival can be a limitation to winter wheat in North Dakota, says a plant scientist at North Dakota State University.

Its Potential

"Earlier crop development helps in avoiding some disease and insect pressure," says Michael Peel, extension agronomist at NDSU. "Winter wheat is no more resistant to scab (Fusarium head blight) than spring wheat, but with a three-week developmental advantage, it may avoid late infection periods that will affect spring wheat."

Orange wheat blossom midge only lay eggs in developing heads between head emergence and flowering. Peel says flowering in winter wheat is complete before the midge emerge, thereby allowing the crop to effectively avoid the pest.

Well-established winter wheat is more competitive with summer annual weeds than spring cereal grains and results in less producer dependence on chemical weed control. A healthy stand of winter wheat has good ground cover, which shades the soil and acts as a strong deterrent against weed growth. Peel says wild oat is rarely a problem in vigorous winter wheat fields.

"Planting and fertilizing winter wheat in the fall lightens spring-planting workloads," Peel says. "Since winter wheat will be ready for harvest two to three weeks before spring wheat, the harvest workload is also spread out. Spreading out planting and harvest provide more efficient use of machinery."

Ensure Winter Survival

Winter survival is the most critical factor in successfully producing a winter wheat crop in the northern plains, Peel says. Cultural practices that help ensure winter survival are those that provide snow cover to maintain warmer soil temperatures in the crown area, just above the plant's root system. NDSU research indicates that 3 inches of snow cover will prevent winterkill due to low temperatures. While a 3-inch layer of snow is sufficient protection during most North Dakota winters, 4 to 6 inches will further reduce the extent of crown injury and increase stand survival.

"Several methods can be used to enhance snow cover," Peel says. "Winter wheat can be no-till seeded directly into flax, barley, mustard, sunflower or other standing crop residues left to catch the snow. Seeding into wheat or durum stubble will increase the risk of some diseases but is preferred to seeding into clean-tilled fields, particularly where disease is less of a problem, since the stubble will enhance moisture conservation and protection from cold weather."

To avoid a "green bridge" for movement of wheat streak mosaic virus, volunteer wheat and grass weeds should be controlled two weeks prior to planting, Peel notes. Grain stubble should be left at least 6 inches tall to obtain the minimum snow cover required. Hoe drills, which permit deeper seed placement and trap snow in furrows over the seed row, are highly recommended for bare fallow, stubble mulch or chemical fallow fields to improve winter survival.

Phosphorus (P) aids overwinter survival by stimulating root growth and fall tillering. The secondary root system that develops with tillering is essential for a healthy deep-rooted plant capable of withstanding stress. If winter wheat is planted on bare soil, an application of P is essential. While important, the contribution of P to overwinter survival is secondary to varietal hardiness.

Varietal Selection

Only the most winter-hardy varieties available should be considered when growing winter wheat in North Dakota. Of the current varieties, Roughrider, Agassiz, Seward, Elkhorn, Ransom and Crimson possess the best combination of winter hardiness and yield. Of the varieties adapted to North Dakota, Crimson has the best tolerance to wheat streak mosaic virus.

"Variety selection is one of the simplest ways to ensure maximum production. A variety that performs the best at several locations over multiple years is the best choice," Peel says.

Producers can refer to the NDSU Extension publication titled "1998 North Dakota Hard Red Spring Wheat and Hard Red Winter Wheat Variety Performance Descriptions" (A-574) for detailed agronomic information on available winter wheat varieties. A summary of 1999 winter wheat yield data is available from county offices of the NDSU Extension Service or can be found on the North Dakota Small Grains Web site (http://www.ag.ndsu.nodak.edu/aginfo/smgrains/smgrains.htm ). Foundation seed of winter wheat is available from NDSU's Agronomy Seed Farm in Casselton by calling (701) 347-4743. Additional information regarding seed is available via the Internet at http://www.ag.ndsu.nodak.edu/aginfo/seedstock/fss/fsshome.htm .

Additional Considerations/Tips

• Planting--The recommended seeding dates for winter wheat are Sept. 10 to Sept. 30 in the southern half of North Dakota and Sept. 1 to Sept. 15 in northern regions. Planting after the recommended dates may reduce winter survival and grain yields. Planting prior to the recommended date unnecessarily depletes soil moisture reserves, increases risk of disease and may reduce winter survival.
• Seeding Rate--Winter wheat should be seeded at a rate of 1 million viable seeds per acre or about 80 pounds per acre. Higher seeding rates are suggested for late seeding or for poor seedbed conditions.
• Fertility--Fertilizer applications for winter wheat should be based on soil tests and yield expectations. Winter wheat's nitrogen (N) need in the fall is low and does not exceed the rate that can safely be applied in the drill row at seeding time. Spring applications of N should be based on a soil test. The best combination of yield and protein are achieved with applications just prior to jointing. N applications on snow are not recommended. Snow compaction under wheel tracks destroys snow insulation properties and results in winterkill beneath the track. Movement of N off-site is also a problem on deeply frozen soils when snow melts in the spring.
• For more information on winter wheat production, refer to the following NDSU Extension publications: "Fertilizing Hard Red Spring Wheat, Durum, Winter Wheat and Rye" (SF-712); "Winter Wheat Production in North Dakota" (EB-33); and "The North Dakota Fertilizer Handbook" (EB-65), $6.50 plus shipping and handling.

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Source: Michael Peel (701) 231-8037
Editor: Dean Hulse (701) 231-6136

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