Feekes scale

The Feekes scale is a system used by agronomists to identify the growth and development of cereal crops. The Feekes scale is more widely used in the United States^[1] than other similar and more descriptive^[2][3] scales such as the Zadoks scale or the BBCH scale. The scale was originally described in 1941^[4] and, like other scales of crop development, is useful in planning management strategies that incorporate plant growth information for the use of pesticides and fertilizers to avoid damaging the crop and/or maximize crop yield.

Cereal growth stages using the Feekes scale[4]
Stage	Description
Tillering
1	One shoot (number of leaves can be added), first leaf through coleoptile.
2	Beginning of tillering; main shoot and one tiller.
3	Tillers formed; leaves often twisted spirally. Main shoot and six tillers. In some varieties of winter wheat, plant may be “creeping,” or prostrate.
4	Beginning of the erection of the pseudo-stem; leaf sheaths beginning to lengthen.
5	Pseudo-stem (formed by sheaths of leaves) strongly erected.
Stem Extension
6	First node of stem visible at base of shoot.
7	Second node of stem formed; next-to-last leaf just visible.
8	Flag leaf (last leaf) visible but still rolled up; ear beginning to swell.
9	Ligule of flag leaf just visible.
10	Sheath of flag leaf completely grown out; ear swollen but not yet visible.
Heading
10.1	First spikelet of head just visible.
10.2	One-quarter of heading process completed.
10.3	Half of heading process completed.
10.4	Three-quarters of heading process completed.
10.5	All heads out of sheath.
Flowering
10.51	Beginning of flowering.
10.52	Flowering complete to top of head.
10.53	Flowering completed at base of head.
10.54	Flowering completed; kernel watery ripe.
Ripening
11.1	Milky ripe.
11.2	Mealy ripe; contents of kernel soft but dry. Soft dough.
11.3	Kernel hard (difficult to divide with thumbnail).
11.4	Ripe for cutting. Straw dead.

References

1. Wise K, Johnson B, Mansfield C, Krupke C. "Managing Wheat by Growth Stage" (PDF). Purdue University Extension. Retrieved 29 February 2012.
2. Miller, Travis. "Growth Stages of Wheat: Identification and Understanding Improve Crop Management" (PDF). Texas Agricultural Extension Service. Retrieved 29 February 2012.
3. Herbek J and Lee C (July 2009). "Section 2. Growth and Development". A Comprehensive Guide to Wheat Management in Kentucky. University of Kentucky College of Agriculture.
4. Large, E. C. (1 December 1954). "GROWTH STAGES IN CEREALS ILLUSTRATION OF THE FEEKES SCALE". Plant Pathology 3 (4): 128–129. doi:10.1111/j.1365-3059.1954.tb00716.x.