In biology, the BBCH-scale for leafy vegetables forming heads describes the phenological development of leafy vegetables forming heads, such as cabbage, chinese cabbage, lettuce and endive, using the BBCH-scale.
Phenology is the study of periodic plant and animal life cycle events and how these are influenced by seasonal and interannual variations in climate, as well as habitat factors.
Cabbage or headed cabbage is a leafy blue, red (purple), or white biennial plant grown as an annual vegetable crop for its dense-leaved heads. It is descended from the wild cabbage, B. oleracea var. oleracea, and belongs to the "cole crops", meaning it is closely related to broccoli and cauliflower ; Brussels sprouts ; and savoy cabbage. Brassica rapa is commonly named Chinese, celery or napa cabbage and has many of the same uses. Cabbage is high in nutritional value.
Chinese cabbage can refer to two groups of Chinese leaf vegetables often used in Chinese cuisine: the Pekinensis Group and the Chinensis Group.
The phenological growth stages and BBCH-identification keys of leafy vegetables forming heads are:
| Growth stage | Code | Description |
|---|---|---|
| 0: Germination | 00 | Dry seed |
| 01 | Beginning of seed imbibition | |
| 03 | Seed imbibition complete | |
| 05 | Radicle emerged from seed | |
| 07 | Hypocotyl with cotyledons breaking through seed coat | |
| 09 | Emergence: cotyledons break through soil surface | |
| 1: Leaf development (Main shoot) | 10 | Cotyledons completely unfolded; growing point or true leaf initial visible |
| 11 | First true leaf unfolded | |
| 12 | 2nd true leaf unfolded | |
| 13 | 3rd true leaf unfolded | |
| 1 . | Stages continuous till . . . | |
| 19 | 9 or more true leaves unfolded | |
| 4: Development of harvestable vegetative plant parts | 41 | Heads begin to form: the two youngest leaves do not unfold |
| 42 | 20% of the expected head size reached | |
| 43 | 30% of the expected head size reached | |
| 44 | 40% of the expected head size reached | |
| 45 | 50% of the expected head size reached | |
| 46 | 60% of the expected head size reached | |
| 47 | 70% of the expected head size reached | |
| 48 | 80% of the expected head size reached | |
| 49 | Typical size, form and firmness of heads reached | |
| 5: Inflorescence emergence | 51 | Main shoot inside head begins to elongate |
| 53 | 30% of the expected height of the main shoot reached | |
| 55 | First individual flowers of main inflorescence visible (still closed) | |
| 57 | First individual flowers of secondary inflorescences visible (still closed) | |
| 59 | First flower petals visible; flowers still closed | |
| 6: Flowering | 60 | First flowers open (sporadically) |
| 61 | Beginning of flowering: 10% of flowers open | |
| 62 | 20% of flowers open | |
| 63 | 30% of flowers open | |
| 64 | 40% of flowers open | |
| 65 | Full flowering: 50% of flowers open | |
| 67 | Flowering finishing: majority of petals fallen or dry | |
| 69 | End of flowering | |
| 7: Development of fruit | 71 | First fruits formed |
| 72 | 20% of fruits have reached typical size | |
| 73 | 30% of fruits have reached typical size | |
| 74 | 40% of fruits have reached typical size | |
| 75 | 50% of fruits have reached typical size | |
| 76 | 60% of fruits have reached typical size | |
| 77 | 70% of fruits have reached typical size | |
| 78 | 80% of fruits have reached typical size | |
| 79 | Fruits have reached typical size | |
| 8: Ripening of fruit and seed | 81 | Beginning of ripening: 10% of fruits ripe, or 10% of seeds of typical colour, dry and hard |
| 82 | 20% of fruits ripe, or 20% of seeds of typical colour, dry and hard | |
| 83 | 30% of fruits ripe, or 30% of seeds of typical colour, dry and hard | |
| 84 | 40% of fruits ripe, or 40% of seeds of typical colour, dry and hard | |
| 85 | 50% of the fruits ripe, or 50% of seeds of typical colour, dry and hard | |
| 86 | 60% of fruits ripe, or 60% of seeds of typical colour, dry and hard | |
| 87 | 70% of fruits ripe, or 70% of seeds of typical colour, dry and hard | |
| 88 | 80% of fruits ripe, or 80% of seeds of typical colour, dry and hard | |
| 89 | Fully ripe: seeds on the whole plant of typical colour and hard | |
| 9: Senescence | 92 | Leaves and shoots beginning to discolour |
| 95 | 50% of leaves yellow or dead | |
| 97 | Plants dead | |
| 99 | Harvested product (seeds) |