Planting recommendations for winter wheat
Much of wheat’s yield potential is determined at planting. To attain top yields, the goal of the planting operation needs to be an even and uniform stand of seedlings. This, along with timely planting, is critically important if improving wheat performance is the goal.
The chance of achieving a consistent stand is greatly improved by ensuring that residue from the previous crop is spread uniformly. Particularly for no-till operations, bunched-up residue is the most common threat to stand evenness.
In some cases, the coulters are unable to cut through the thick residue, or the emerging wheat simply rots below the layers of plant material. Adding weight to the drill may help in penetrating crop residue (or hard soil). In some cases, the only alternative would be to use tillage to help disburse and bury the residue.
The highest yields are most likely to be attained when planting within two weeks following the Hessian fly-free date. Of course, the reality is that the preceding crop and current weather largely dictate when wheat is actually planted. Nevertheless, it is important to be as timely as possible to ensure seedlings have sufficient time to develop a strong root system and initiate multiple tillers.
• Improving wheat yields depends on achieving uniform wheat stands this fall.
• Planting within two weeks following the Hessian fly-free date is ideal.
• Seeding rate recommendation is between 1.4 million and 2.2 million seeds per acre.
Once a couple weeks have passed beyond the fly-free date, yield potential tends to decline at least 1 bushel for each additional day of delay.
While the Hessian fly no longer poses a major threat to wheat in Michigan, the Hessian fly-free date is still a useful reference relative to wheat and disease development. Growers may do well to plant a fraction of their acreage within a few days of the fly-free date. However, planting wheat prior to that date is generally not encouraged as the crop may be at greater risk from viral and fungal diseases.
Attaining a consistent depth and thus even emergence is often more critical for achieving high yields than fine-tuning actual seeding depth. Usually, a planting depth of about 1 inch will be deep enough to reach adequate soil moisture, provide for well-anchored plants and offer some protection against winter injury.
An exception, however, is where the soil is exceptionally dry. In this case, the seed should be placed as deep as necessary to find moisture.
The recommendation is to plant between 1.4 million and 2.2 million seeds per acre. Seeding rates on the lower end of the range should be reserved for fields being planted within a couple weeks of the fly-free date. Higher rates at this time are discouraged as overly thick stands may encourage lodging, as was experienced by some growers during the 2010-11 season.
As the season goes on, the seeding rates should become progressively higher. If planting continues into the second half of October, the seed rate should be increased to at least 2 million per acre. The seeding rates should also be adjusted upward when seed is of questionable quality.
About 10 to 25 pounds of fertilizer nitrogen is recommended at planting. However, because of this season’s drought, growers may be able to forego nitrogen when planting relatively early following a high-nitrogen crop such as corn silage, as there may be plenty of residual nitrogen.
All phosphorus and potash should be applied in the fall with rates determined by soil test levels. In general, soils having medium test levels of phosphorus (25 to 40 ppm) require about 50 pounds per acre of phosphate. For soils testing medium for potassium (75 to 100 ppm), about 100 pounds per acre of potash may be enough.
Nagelkirk writes for Michigan State University Extension.
This article published in the October, 2012 edition of MICHIGAN FARMER.