Cereal growth staging scales attempt to objectively measure the growth of cereals.

BBCH-scale (cereals)

In agronomy, the BBCH-scale for cereals describes the phenological development of cereals using the BBCH-scale.

Critical stages according to BBCH (Lancashire et al., 1991) and their deviations from the Zadok's scale (in brackets). The spacing between the stages follows calendar time for the temperate climate of Switzerland (sowing in November, harvest mid-July)

The phenological growth stages and BBCH-identification keys of cereals are:

Growth stageCodeDescription
0: Germination 00Dry seed (caryopsis)
01Beginning of seed imbibition
03Seed imbibition complete
05Radicle emerged from caryopsis
06Radicle elongated, root hairs and/or side roots visible
07Coleoptile emerged from caryopsis
09Emergence: coleoptile penetrates soil surface (cracking stage)
1: Leaf development1, 2 10First leaf through coleoptile
11First leaf unfolded
122 leaves unfolded
133 leaves unfolded
1 .Stages continuous till ...
199 or more leaves unfolded
2: Tillering3 20No tillers
21Beginning of tillering: first tiller detectable
222 tillers detectable
233 tillers detectable
2 .Stages continuous till ...
29End of tillering. Maximum no. of tillers detectable
3: Stem elongation 30Beginning of stem elongation: pseudostem and tillers erect, first internode begins to elongate, top of inflorescence at least 1 cm above tillering node
31First node at least 1 cm above tillering node
32Node 2 at least 2 cm above node 1
33Node 3 at least 2 cm above node 2
3 .Stages continuous till ...
37Flag leaf just visible, still rolled
39Flag leaf stage: flag leaf fully unrolled, ligule just visible
4: Booting 41Early boot stage: flag leaf sheath extending
43Mid boot stage: flag leaf sheath just visibly swollen
45Late boot stage: flag leaf sheath swollen
47Flag leaf sheath opening
49First awns visible (in awned forms only)
5: Inflorescence emergence, heading 51Beginning of heading: tip of inflorescence emerged from sheath, first spikelet just visible
5220% of inflorescence emerged
5330% of inflorescence emerged
5440% of inflorescence emerged
55Middle of heading: half of inflorescence emerged
5660% of inflorescence emerged
5770% of inflorescence emerged
5880% of inflorescence emerged
59End of heading: inflorescence fully emerged
6: Flowering, anthesis 61Beginning of flowering: first anthers visible
65Full flowering: 50% of anthers mature
69End of flowering: all spikelets have completed flowering but some dehydrated anthers may remain
7: Development of fruit 71Watery ripe: first grains have reached half their final size
73Early milk
75Medium milk: grain content milky, grains reached final size,

still green

77Late milk
8: Ripening 83Early dough
85Soft dough: grain content soft but dry. Fingernail impression not held
87Hard dough: grain content solid. Fingernail impression held
89Fully ripe: grain hard, difficult to divide with thumbnail
9: Senescence 92Over-ripe: grain very hard, cannot be dented by thumbnail
93Grains loosening in day-time
97Plant dead and collapsing
99Harvested product
  • 1 A leaf is unfolded when its ligule is visible or the tip of the next leaf is visible
  • 2 Tillering or stem elongation may occur earlier than stage 13; in this case continue

with stages 21

  • 3 If stem elongation begins before the end of tillering continue with stage 30

Feekes scale

The Feekes scale is a system to identify the growth and development of cereal crops introduced by the Dutch agronomists Willem Feekes (1907-1979) in 1941.[1][2] This scale is more widely used in the United States[3] than other similar and more descriptive[4][5] scales such as the Zadoks scale or the BBCH scale. Like other scales of crop development, the Feekes scale 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[2]
Stage Description
Tillering
1One shoot (number of leaves can be added), first leaf through coleoptile.
2Beginning of tillering; main shoot and one tiller.
3Tillers formed; leaves often twisted spirally. Main shoot and six tillers. In some varieties of winter wheat, plant may be "creeping," or prostrate.
4Beginning of the erection of the pseudo-stem; leaf sheaths beginning to lengthen.
5Pseudo-stem (formed by sheaths of leaves) strongly erected.
Stem Extension
6First node of stem visible at base of shoot.
7Second node of stem formed; next-to-last leaf just visible.
8Flag leaf (last leaf) visible but still rolled up; ear beginning to swell.
9Ligule of flag leaf just visible.
10Sheath of flag leaf completely grown out; ear swollen but not yet visible.
Heading
10.1First spikelet of head just visible.
10.2One-quarter of heading process completed.
10.3Half of heading process completed.
10.4Three-quarters of heading process completed.
10.5All heads out of sheath.
Flowering
10.51Beginning of flowering.
10.52Flowering complete to top of head.
10.53Flowering completed at base of head.
10.54Flowering completed; kernel watery ripe.
Ripening
11.1Milky ripe.
11.2Mealy ripe; contents of kernel soft but dry. Soft dough.
11.3Kernel hard (difficult to divide with thumbnail).
11.4Ripe for cutting. Straw dead.

Zadoks scale

The Zadoks scale is a cereal development scale proposed by the Dutch phytopathologist Jan Zadoks that is widely used in cereal research and agriculture. Knowing the stages of development of a crop is critical in many management decisions that growers make. They are represented on a scale from 10 to 92. For example, in some countries, nitrogen and herbicide applications must be completed during the tillering stage. In France, the recommendation for the first nitrogen application on wheat is 6 weeks before Z30, with the second application on Z30. Wheat growth regulators are typically applied at Z30. Disease control is most critical in the stem extension and heading stage (Z31, Z32, Z35), in particular as soon as the flag leaf is out (Z37). The crop is also more sensitive to heat or frost at some stages than others (for example, during the meiosis stage the crop is very sensitive to low temperature). Knowing the growth stage of the crop when checking for problems is essential for deciding which control measures should be followed.

Examples of typical stages

  • during tillering
    • Z10: one leaf
    • Z21: tillering begins
  • during stem extension
    • Z30: ear is one centimeter long in wheat
    • Z31: first node visible
    • Z32: second node visible
    • Z37: flag leaf
  • during heading
    • Z55: the head is 1/2 emerged.
  • during ripening
    • Z92: grains are ripe
Comparison of growth stage scales
Zadok
Scale
Feekes
Scale
Haun
Scale
Description
Germination
00Dry seed
01Start of imbibition
03Imbibition complete
05Radicle emerged from seed
07Coleoptile emerged from seed
090.0Leaf just at coleoptile tip
Seedling growth
101First leaf through coleoptile
111.+First leaf unfolded
121.+2 leaves unfolded
132.+3 leaves unfolded
143.+4 leaves unfolded
154.+5 leaves unfolded
165.+6 leaves unfolded
176.+7 leaves unfolded
187.+8 leaves unfolded
199 or more leaves unfolded
Tillering
20Main shoot only
212Main shoot and 1 tiller
22Main shoot and 2 tillers
23Main shoot and 3 tillers
24Main shoot and 4 tillers
25Main shoot and 5 tillers
263Main shoot and 6 tillers
27Main shoot and 7 tillers
28Main shoot and 8 tillers
29Main shoot and 9 or more tillers
Stem Elongation
304-5Pseudo stem erection
3161st node detectable
3272nd node detectable
333rd node detectable
344th node detectable
355th node detectable
366th node detectable
378Flag leaf just visible
399Flag leaf ligule/collar just visible
Booting
40-
418-9Flag leaf sheath extending
45109.2Boots just swollen
47Flag leaf sheath opening
4910.1First awns visible
Inflorescence emergence
5010.110.2First spikelet of inflorescence visible
5310.21/4 of inflorescence emerged
5510.310.51/2 of inflorescence emerged
5710.410.73/4 of inflorescence emerged
5910.511.0Emergence of inflorescence completed
Anthesis
6010.5111.4Beginning on anthesis
6511.5Anthesis half-way
6911.6Anthesis completed
Milk development
70-
7110.5412.1Kernel watery ripe
7313.0Early milk
7511.1Medium milk
77Late milk
Dough development
80-
8314.0Early dough
8511.2Soft dough
8715.0Hard dough
Ripening
90-
9111.3Kernel hard (difficult to divide with thumbnail)
9211.416.0Kernel hard (no longer dented with thumbnail)
93Kernel loosening in daytime
94Overripe, straw dead and collapsing
95Seed dormant
96Viable seed giving 50% germination
97Seed not dormant
98Secondary dormancy induced
99Secondary dormancy lost

References

  1. Feekes, Willem (1941). "De tarwe en haar milieu [Wheat and its environment]". Verslagen van de Technische Tarwe Commissie. (in Dutch and English). 17: 523–888.
  2. 1 2 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.
  3. Wise K, Johnson B, Mansfield C, Krupke C. "Managing Wheat by Growth Stage" (PDF). Purdue University Extension. Retrieved 29 February 2012.
  4. Miller, Travis. "Growth Stages of Wheat: Identification and Understanding Improve Crop Management" (PDF). Texas Agricultural Extension Service. Archived from the original (PDF) on 25 November 2011. Retrieved 29 February 2012.
  5. Herbek J, Lee C (July 2009). "Section 2. Growth and Development". A Comprehensive Guide to Wheat Management in Kentucky. University of Kentucky College of Agriculture. Archived from the original on 2015-09-23. Retrieved 2016-05-14.
  • Lancashire, P.D.; H. Bleiholder; P. Langeluddecke; R. Stauss; T. van den Boom; E. Weber; A. Witzen-Berger (1991). "A uniform decimal code for growth stages of crops and weeds". Ann. Appl. Biol. 119 (3): 561–601. doi:10.1111/j.1744-7348.1991.tb04895.x.
  • Lancashire, P.D.; H. Bleiholder; P. Langeluddecke; R. Stauss; T. van den Boom; E. Weber; A. Witzen-Berger (1991). "A uniform decimal code for growth stages of crops and weeds". Ann. Appl. Biol. 119 (3): 561–601. doi:10.1111/j.1744-7348.1991.tb04895.x.
  • Witzenberger, A.; H. Hack; T. van den Boom (1989). "Erläuterungen zum BBCH-Dezimal-Code für die Entwicklungsstadien des Getreides - mit Abbildungen". Gesunde Pflanzen. 41: 384–388.

Further reading

  • J.C. Zadoks, T.T. Chang, C.F. Konzak, "A Decimal Code for the Growth Stages of Cereals", Weed Research 1974 14:415-421.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.