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The growth stages of oilseed rape
It is useful to break down the life cycle of oilseed rape into various growth stages. By understanding the main crop development stages, it becomes easier to measure crop performance and informs husbandry choices.
Oilseed rape growth guide home
What are growth stages and why are they important?
A plant’s life cycle can be described by ten developmental phases.
Understanding the principal growth stages (GS) can help assist with management decisions. For example, this uniform coding system, which is also used for cereals, features on plant protection product labels.
There are two systems in use: The BBCH (Biologische Bundesanstalt, Bundessortenamt und CHemical Industry) and AAB scales. Although there are striking similarities, there are also some key differences between them.
Although the principal growth stages start in chronological order, the beginning of each stage is not dependent on the completion of the preceding stage. As a result, several stages overlap. Where overlaps occur, the guidance is to use the GS for the most advanced stage (e.g. the higher number). How quickly the crop moves through each stage depends on its environment and the variety.
Principal growth stages (BBCH system)
Principal growth and secondary growth stage keys
BBCH system
GS0: Germination and emergence
00: Seed dry
01: Seed imbibition starts
03: Seed imbibition complete
05: Radicle (embryonic root) emerged from seed
07: Cotyledons emerged from seed
09: Cotyledons emerged through soil surface
GS1: Leaf development
10: Cotyledons completely unfolded
11: First leaf unfolded
12: Second leaf unfolded
19: Nine or more leaves unfolded
GS2: Side-shoot formation
20: No side shoots
21: First side shoot detectable
22: Second side shoot detectable
29: Nine or more side shoots detectable
GS3: Stem elongation/extension
30: No internodes (rosette stage)
31: One visibly extended internode
32: Two visibly extended internodes
39: Nine or more visibly extended internodes
GS4: Does not apply to oilseed rape
GS5: Inflorescence/flower-bud emergence
50: Flower buds present and enclosed by leaves
51: Flower buds visible from above (‘green bud’ stage)
52: Flower buds free and level with the youngest leaves
53: Flower buds raised above the youngest leaves
55: Individual flower buds (main inflorescence) visible but closed
57: Individual flower buds (secondary inflorescences) visible but closed
59: Flower buds closed with first petals visible (‘yellow bud’ stage)
GS6: Flowering
60: First flowers open
61: 10% of flowers on main raceme open
62: 20% of flowers on main raceme open
65: 50% flowers on main raceme open, older petals falling (‘full flower’ stage)
67: Flowering declining, most petals fallen
69: End of flowering
GS7: Pod/seed (fruit) development
71: 10% of pods have reached final size
72: 20% of pods have reached final size
79: >90% of pods have reached final size
GS8: Pod/seed (fruit) ripening
80: Ripening starts (seeds green and filling pod cavity)
81: 10% of pods ripe, with seeds dark and hard
82: 20% of pods ripe, with seeds dark and hard
89: >90% nearly all pods ripe, with seeds dark and hard
GS9: Senescence
90: Plant death starts
97: Plant dead and dry
99: Harvested product
*Adapted from ‘Growth stages of mono- and dicotyledonous plants’ (BBCH Monograph), 2001.
AAB system
GS0: Germination and emergence
0.0: Dry seed
0.9: Cotyledons emerge through soil surface
GS1: Leaf production
1.0: Cotyledons unfolded
1.1: First true leaf
1.2: Second true leaf
1.6: Sixth true leaf
GS2: Stem extension
2.0: No internodes (rosette)
2.1: One internode
2.2: Two internodes
2.5: Five internodes
GS3: Flower-bud development
3.0: No flower buds present (only leaf buds present)
3.1: Flower buds enclosed by leaves
3.3: First flower buds visible from above ('green bud')
3.5: First flower buds raised above leaves
3.6: First flower stalks extending
3.7: First flower buds yellow ('yellow bud')
GS4: Flowering
4.0: First flower opened
4.1: 10% of flower buds opened
4.2: 20% of flower buds opened
4.5: 50% of flower buds opened
GS5: Pod development
5.0: 0% of potential pods
5.1: 10% of potential pods
5.2: 20% of potential pods
5.5: 50% of potential pods
GS6: Seed development
6.0: No seeds expanding
6.1: Seeds expanding
6.2: Most seeds translucent but full size
6.3: Most seeds green
6.4: Most seeds green-brown mottled
6.5: Most seeds brown
6.6: Most seeds dark brown
6.7: Most seeds black but soft
6.8: Most seeds black and hard
6.9: All seeds black and hard
GS7: Leaf senescence
GS8: Stem senescence
8.0: All stem green
8.1: Most stem green
8.5: Half stem green
8.9: Little stem green
GS9: Pod senescence
9.0: All pods green
9.1: Most pods green
9.5: Half pods green
9.9: Few pods green
*Adapted from Sylvester-Bradley, 1985. Aspects of Applied Biology 10: 395–400