The growth stages of cereals

It is useful to break down the cereal life cycle into various growth stages. By understanding the main crop development stages, it becomes easier to measure crop performance and informs husbandry choices.

Wheat growth guide

Barley growth guide

Oat growth guide

Oilseed rape growth guide

What are growth stages and why are they important?

The BBCH (Biologische Bundesanstalt, Bundessortenamt und CHemical Industry) scale is the main system in cereals, based on ten developmental phases – the principal growth stages (GS). Understanding the system can aid with the benchmarking of crop development and help assist management decisions. For example, this uniform coding system features on plant protection product labels.

GS0: Germination and emergence

GS00: Dry seed (caryopsis)

GS01: Beginning of seed imbibition

GS03: Seed imbibition complete

GS05: Radicle emerged

GS06: Radicle elongated, root hairs and/or side roots visible

GS07: Coleoptile (pointed protective sheath covering the emerging shoot) emerged

GS09: Emergence. Coleoptile penetrates soil surface (cracking stage)

GS1: Leaf development (seedling growth)

GS10: First leaf through coleoptile

GS11: First leaf unfolded (ligule visible)

GS13: Three leaves unfolded on the main shoot

GS15: Five leaves unfolded

GS19: Nine or more leaves unfolded on the main stem

GS2: Tillering (production of side shoots)

GS20: Main shoot only (no tillers)

GS21: Main shoot and one tiller

GS23: Main shoot and three tillers

GS25: Main shoot and five tillers

GS29: Main shoot and nine or more tillers

GS3: Stem elongation

GS30: Ear at 1cm (pseudostem erect)

GS31: First node detectable

GS32: Second node detectable

GS33: Third node detectable

GS37: Flag leaf just visible

GS39: Flag leaf fully unrolled, ligule just visible

How to count cereal nodes

An internode is the part of a plant stem between two successive nodes. The first node detectable must be above an internode of at least 1cm*. The second and subsequent nodes detectable must be above an internode of at least 2cm. *Sometimes a node may be underground and bear roots. As long as the internode below it exceeds 1cm, count it.

GS4: Booting

GS41: Flag leaf sheath extending (early-boot stage)

GS43: Flag leaf sheath just visibly swollen (mid-boot stage)

GS45: Flag leaf sheath swollen (late-boot stage)

GS47: Flag leaf sheath opening

GS49: First awns visible

GS5: Ear/Inflorescence emergence

GS51: First spikelet of ear just visible above flag leaf ligule

GS55: Half of ear emerged above flag leaf ligule

GS59: Ear completely emerged above flag leaf ligule

GS6: Flowering/anthesis

GS61: Start of flowering (first anthers visible)

GS65: Flowering halfway (50% of anthers mature)

GS69: Flowering complete (some dehydrated anthers may remain)

GS7: Milk/seed/grain/fruit development

GS71: Watery ripe (first grains half final size)

GS73: Early milk

GS75: Medium milk (grain content milky, grains reached final size)

GS77: Late milk

GS8: Dough development

GS83: Early dough

GS85: Soft dough (content soft but dry)

GS87: Hard dough (thumbnail impression held)

GS89: Fully ripe (grain hard, difficult to divide with thumbnail)

GS9: Ripening/senescence

GS91: Grain hard (difficult to divide)

GS92: Grain hard (not dented by thumbnail)

GS93: Grain loosening in daytime

GS97: Plant dead and collapsing

GS99: Harvested product