Using more wheat seed as the fall progresses
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EmailA practice proved helpful to wheat growers is to increase seed use as winter approaches.
It has long been recognized that more seed should be used as the fall progresses. These inflated rates for delayed planting are an attempt to partially compensate for the delayed spring-time development and reduced tiller numbers that result when planting relatively late in the year. In addition, the heavier densities are occasionally advantageous under adverse winter conditions.
Growers would do well to develop their own strategy for ramping up seeding rates. The table below is an example of matching planting dates (expressed as days following the fly-free date) with seeding rates and expected seedling densities. Growers can generally do well sowing only 1.2 to 1.4 million seeds per acre when planting within several days of the Hessian fly-free date (See the Michigan State University Extension article Winter wheat planting recommendations.) This rate should provide a high percentage yield of seedlings, perhaps 15 to 19 per foot of row. It will also have the luxury of time to develop plenty of fall growth.
Strategy for increasing seeding rates and seedling density (example for 7.5-inch row spacing)
|
Days following |
Seeding rate (millions/ac) |
Seeds per ft of row1 |
Seedlings per ft of row2 |
|
0 - 7 |
1.4 |
20.1 |
18.5 (92%) |
|
8 - 14 |
1.6 |
23.0 |
20.7 (90%) |
|
15 - 21 |
1.8 |
25.8 |
22.7 (88%) |
|
2 - 28 |
2.0 |
28.7 |
24.7 (86%) |
|
28 plus |
2.2 |
31.6 |
26.5 (84%) |
1 Target seeding rate / 43,560 X 0.625
= seeds per ft of row (7.5-inch spacing).
2 An estimated emergence rate (seedlings
per seed number) is given in brackets as percent (rate declines as seed rates
increase).
However, as September wanes and October arrives, growers in central Michigan might begin planning to bump the rate to 1.6, and eventually to 1.8 million seeds per acre. Then, as the example suggests, the rate could be further increased to perhaps 2 to 2.2 million seeds when the calendar shows some four weeks have lapsed since the fly-free date.
