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Winter Wheat Planting Considerations

Aug 28, 2013

Bob Fanning
SDSU Extension Plant Pathology Field Specialist

Winter wheat planting season is around the corner. Here are some tips that will set the crop for success:

  • Choose one or more varieties with good agronomic characteristics that are recommended for your area, and on average, performed well in locations near your farm in the last few years.
  • When possible, direct seed into standing stubble. Standing stubble traps snow which insulates wheat seedlings against cold temperatures, reducing risk of winterkill. Seeding into broadleaf crop stubble reduces the risk of insect, disease and weed problems in the rotation. Seeding into wheat stubble is often done, but increases the risk of residue-borne diseases the following season. Seeding wheat into corn, wheat, sorghum or millet residue increases the risk of scab (Fusarium Head Blight). If planting winter wheat into a fallow field, minimize the number of tillage operations just before planting. Plowing and other deep tillage operations can reduce seedbed firmness, dry the topsoil and bury protective residues, increasing the risk of winter kill.
  • Control weeds early. Controlling grassy weeds and volunteer wheat two weeks prior to planting winter wheat will provide a break in the life cycle of the wheat curl mite and help to control wheat streak mosaic virus and other diseases. Preventing annual weeds from producing seed will help reduce weed problems in the planted crop. Prior to planting winter wheat is also a good time to control perennial weeds and reduce competition from them in the following season.
  • In South Dakota the recommended time to plant winter wheat is Sept. 15 through Oct. 10. Wheat plants should be well established before freezing to attain maximum cold tolerance and accumulate enough energy reserves for the following spring. Planting wheat too early may produce excessive fall growth, reducing amounts of soil moisture and nutrients. Early planted wheat is vulnerable to infestations of wheat curl mites that transmit wheat streak mosaic virus and also increases the risk of root and crown rot diseases. Research from western South Dakota has shown that grain yield is decreased and the crop can suffer substantial winter injury when planting later than Oct. 15.
  • Plant winter wheat at a depth of 1.5 to 2 inches in a firm seedbed. Planting deeper than 2 inches reduces emergence and can result in weak spindly seedlings with poor ability to survive the winter. For direct seeding, a uniform depth of 1 to 1.5 inches under optimum moisture conditions will give a good stand. If it is necessary to plant deeper to get to moisture, growers should choose a variety with a longer coleoptile (Table 3 of 2010 Winter Wheat Variety Yield Results and Planting Tips). Make sure there is good soil-to-seed contact, especially under drier conditions. If soil cover over the seed is poor there is risk of exposing the crown and adversely affecting winter survival.
  • The recommended seeding rate is at least 22 pure live seeds per square foot (approximately 960,000 seeds/acre, depending on seed size). If you have a poor seedbed or are planting later than the recommended dates, increase seeding rate to 28 pure-live-seeds per square foot. Properly managed winter wheat does have the ability to tiller and can compensate for thin stands. Producers striving for high yield wheat tend to use higher seeding rates. Higher rates tend to produce fewer tillers, a higher percentage of large heads and more uniform flowering and maturity. Heads that flower over a shorter period of time allow for more timely application of fungicides for protection against scab (Fusarium Head Blight). Producers who fit this scenario and particularly those in higher rainfall areas may want to plant 28 pure live seeds per square foot (approximately 1.2 million seeds per acre, depending on seed size) or more.
  • Test soils and apply fertilizer based on soil test results and yield goals. Research has shown that phosphorus helps winter survival by stimulating root growth and tillering in the fall. If soil test results indicate low phosphorus levels, application of the required rate is recommended.

Source : SDSU