# BBCH-scale (bulb vegetable)

In biology, the BBCH-scale for bulb vegetables describes the phenological development of bulb vegetable plants, such as onion, leek, garlic and shallot, using the BBCH-scale.
The phenological growth stages and BBCH-identification keys of bulb vegetables are:
| Growth stage | Code (2-digit) | Code (3-digit) | Description |
| 0: Germination | 00 | 000 | Dry seed,$^1$ dormant bulb$^2$ |
| 0: Germination | 01 | 000 | Beginning of seed imbibition$^1$ |
| 0: Germination | 03 | 003 | Seed imbibition complete$^1$ |
| 0: Germination | 05 | 005 | Radicle emerged from seed.$^1$ Roots appearing$^2$ |
| 0: Germination | 07 | 007 | Cotyledon breaking through seed coat$^1$ |
| 0: Germination | 09 | 009 | Emergence: cotyledon breaks through soil surface.$^1$ Green shoot visible$^2$ |
| 0: Germination | | 010 | Cotyledon visible as hook$^1$ |
| 0: Germination | | 011 | Hook stage: hooked cotyledon green$^1$ |
| 0: Germination | | 012 | Whip stage: cotyledon has whip-like form$^1$ |
| 1: Leaf development (Main shoot) | 10 | 100 | Advanced whip stage: whip begins to die off$^1$ |
| 1: Leaf development (Main shoot) | 11 | 101 | First leaf (> 3 cm) clearly visible |
| 1: Leaf development (Main shoot) | 12 | 102 | 2nd leaf (> 3 cm) clearly visible |
| 1: Leaf development (Main shoot) | 13 | 103 | 3rd leaf (> 3 cm) |
| 1: Leaf development (Main shoot) | 1 . | 10 . | Stages continuous till . . . |
| 1: Leaf development (Main shoot) | 19 | 109 | 9 or more leaves clearly visible |
| 4: Development of harvestable vegetative plant parts | 41 | 401 | Leaf bases begin to thicken or extend |
| 4: Development of harvestable vegetative plant parts | 43 | 403 | 30% of the expected bulb or shaft diameter reached |
| 4: Development of harvestable vegetative plant parts | 45 | 405 | 50% of the expected bulb or shaft diameter reached |
| 4: Development of harvestable vegetative plant parts | 47 | 407 | Bolting begins; in 10% of the plants leaves bent over$^3$ 70% of the expected shaft length and diameter reached$^4$ |
| 4: Development of harvestable vegetative plant parts | 48 | 408 | Leaves bent over in 50% of plants$^3$ |
| 4: Development of harvestable vegetative plant parts | 49 | 409 | Leaves dead, bulb top dry; dormancy$^3$ Growth complete; length and stem diameter typical for variety reached$^4$ |
| 5: Inflorescence emergence | 51 | 501 | Onion bulb begins to elongate |
| 5: Inflorescence emergence | 53 | 503 | 30% of the expected length of flower stem reached |
| 5: Inflorescence emergence | 55 | 505 | Flower stem at full length; sheath closed |
| 5: Inflorescence emergence | 57 | 507 | Sheath burst open |
| 5: Inflorescence emergence | 59 | 509 | First flower petals visible; flowers still closed |
| 6: Flowering | 60 | 600 | First flowers open (sporadically) |
| 6: Flowering | 61 | 601 | Beginning of flowering: 10% of flowers open |
| 6: Flowering | 62 | 602 | 20% of flowers open |
| 6: Flowering | 63 | 603 | 30% of flowers open |
| 6: Flowering | 64 | 604 | 40% of flowers open |
| 6: Flowering | 65 | 605 | Full flowering: 50% of flowers open |
| 6: Flowering | 67 | 607 | Flowering finishing: 70% of petals fallen or dry |
| 6: Flowering | 69 | 609 | End of flowering |
| 7: Development of fruit | 71 | 701 | First capsules formed |
| 7: Development of fruit | 72 | 702 | 20% of capsules formed |
| 7: Development of fruit | 73 | 703 | 30% of capsules formed |
| 7: Development of fruit | 74 | 704 | 40% of capsules formed |
| 7: Development of fruit | 75 | 705 | 50% of capsules formed |
| 7: Development of fruit | 76 | 706 | 60% of capsules formed |
| 7: Development of fruit | 77 | 707 | 70% of capsules formed |
| 7: Development of fruit | 78 | 708 | 80% of capsules formed |
| 7: Development of fruit | 79 | 709 | Capsule development complete; seeds pale |
| 8: Ripening of fruit and seed | 81 | 801 | Beginning of ripening: 10% of capsules ripe |
| 8: Ripening of fruit and seed | 85 | 805 | First capsules bursting |
| 8: Ripening of fruit and seed | 89 | 809 | Fully ripe: seeds black and hard |
| 9: Senescence | 92 | 902 | Leaves and shoots beginning to discolour |
| 9: Senescence | 95 | 905 | 50% of leaves yellow or dead |
| 9: Senescence | 97 | 907 | Plants or above ground parts dead |
| 9: Senescence | 99 | 909 | Harvested product (seeds) |
1 Seed sown 2 Onion sets, shallot and garlic 3 For onions, garlic 4 For leek