Tuesday, February 5, 2013

Key Winter Wheat Stages

Chad Lee, Extension Agronomist, University of Kentucky

Wheat at 70 to 100 tillers per square foot is considered an adequate stand.Wheat at the lower end of the range would be a candidate for a low rate of fertilizer nitrogen applied at Feeke's 3, which normally occurs in late February or early March. Wheat above 100 tillers per square foot are at an excessive population and should not have any nitrogen added at Feeke's 3.Instead, a single application should be made a little later at Feeke's 4-5 (around mid-March).

Table 1. Key numbers in wheat.

Crop Stage Number Units
Emergence 25 plants/sq.ft.
Tillering 70 to 100 tillers/sq.ft.
Heading 60 to 70 heads/sq.ft.
Heading 35 kernels/head

Use Table 2 as a guide for measuring 1 square foot in a wheat field.

Table 2. Length of Row Needed for One Square Foot.
Row width (inches) Length of row needed for 1 sq ft (inches)
4 36
6 24
7 20.6
7.5 19.2
8 18
10 14.4
If a split application of nitrogen is to be used, then the first application is applied at Feeke's 3 and the second is applied at about Feeke's 5 (in mid- to late-March). Total N (from both applications) should be in the range of 80 to 120 lbs/acre for no-tillage wheat and about 60 to 100 lbs/acre for tilled wheat.

For more information on stand counts or nitrogen management