Cereal growth staging scales


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.
The phenological growth stages and BBCH-identification keys of cereals are:
Growth stageCodeDescription
0: Germination00Dry seed
0: Germination01Beginning of seed imbibition
0: Germination03Seed imbibition complete
0: Germination05Radicle emerged from caryopsis
0: Germination06Radicle elongated, root hairs and/or side roots visible
0: Germination07Coleoptile emerged from caryopsis
0: Germination09Emergence: coleoptile penetrates soil surface
1: Leaf development1, 210First leaf through coleoptile
1: Leaf development1, 211First leaf unfolded
1: Leaf development1, 2122 leaves unfolded
1: Leaf development1, 2133 leaves unfolded
1: Leaf development1, 21.Stages continuous till...
1: Leaf development1, 2199 or more leaves unfolded
2: Tillering320No tillers
2: Tillering321Beginning of tillering: first tiller detectable
2: Tillering3222 tillers detectable
2: Tillering3233 tillers detectable
2: Tillering32.Stages continuous till...
2: Tillering329End of tillering. Maximum no. of tillers detectable
3: Stem elongation30Beginning of stem elongation: pseudostem and tillers erect, first internode begins to elongate, top of inflorescence at least 1 cm above tillering node
3: Stem elongation31First node at least 1 cm above tillering node
3: Stem elongation32Node 2 at least 2 cm above node 1
3: Stem elongation33Node 3 at least 2 cm above node 2
3: Stem elongation3.Stages continuous till...
3: Stem elongation37Flag leaf just visible, still rolled
3: Stem elongation39Flag leaf stage: flag leaf fully unrolled, ligule just visible
4: Booting41Early boot stage: flag leaf sheath extending
4: Booting43Mid boot stage: flag leaf sheath just visibly swollen
4: Booting45Late boot stage: flag leaf sheath swollen
4: Booting47Flag leaf sheath opening
4: Booting49First awns visible
5: Inflorescence emergence, heading51Beginning of heading: tip of inflorescence emerged from sheath, first spikelet just visible
5: Inflorescence emergence, heading5220% of inflorescence emerged
5: Inflorescence emergence, heading5330% of inflorescence emerged
5: Inflorescence emergence, heading5440% of inflorescence emerged
5: Inflorescence emergence, heading55Middle of heading: half of inflorescence emerged
5: Inflorescence emergence, heading5660% of inflorescence emerged
5: Inflorescence emergence, heading5770% of inflorescence emerged
5: Inflorescence emergence, heading5880% of inflorescence emerged
5: Inflorescence emergence, heading59End of heading: inflorescence fully emerged
6: Flowering, anthesis61Beginning of flowering: first anthers visible
6: Flowering, anthesis65Full flowering: 50% of anthers mature
6: Flowering, anthesis69End of flowering: all spikelets have completed flowering but some dehydrated anthers may remain
7: Development of fruit71Watery ripe: first grains have reached half their final size
7: Development of fruit73Early milk
7: Development of fruit75Medium milk: grain content milky, grains reached final size,
still green
7: Development of fruit77Late milk
8: Ripening83Early dough
8: Ripening85Soft dough: grain content soft but dry. Fingernail impression not held
8: Ripening87Hard dough: grain content solid. Fingernail impression held
8: Ripening89Fully ripe: grain hard, difficult to divide with thumbnail
9: Senescence92Over-ripe: grain very hard, cannot be dented by thumbnail
9: Senescence93Grains loosening in day-time
9: Senescence97Plant dead and collapsing
9: Senescence99Harvested product

with stages 21
The Feekes scale is a system to identify the growth and development of cereal crops introduced by the Dutch agronomists Willem Feekes in 1941. This scale is more widely used in the United States than other similar and more descriptive 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.

Zadoks scale

The Zadoks scale is a cereal development scale proposed by the Dutch phytopathologist Jan C. 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, in particular as soon as the flag leaf is out. The crop is also more sensitive to heat or frost at some stages than others. 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