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 stageCode (2-digit)Code (3-digit)Description0: Germination00 000 Dry seed,1 dormant bulb201 000 Beginning of seed imbibition103 003 Seed imbibition complete105 005 Radicle emerged from seed.1 Roots appearing207 007 Cotyledon breaking through seed coat109 009 Emergence: cotyledon breaks through soil surface.1 Green shoot visible2 010 Cotyledon visible as hook1 011 Hook stage: hooked cotyledon green1 012 Whip stage: cotyledon has whip-like form11: Leaf development (Main shoot)10 100 Advanced whip stage: whip begins to die off111 101 First leaf (> 3 cm) clearly visible12 102 2nd leaf (> 3 cm) clearly visible13 103 3rd leaf (> 3 cm)1 . 10 . Stages continuous till . . .19 109 9 or more leaves clearly visible4: Development of harvestable vegetative plant parts41 401 Leaf bases begin to thicken or extend43 403 30% of the expected bulb or shaft diameter reached45 405 50% of the expected bulb or shaft diameter reached47 407 Bolting begins; in 10% of the plants leaves bent over3 70% of the expected shaft length and diameter reached448 408 Leaves bent over in 50% of plants349 409 Leaves dead, bulb top dry; dormancy3 Growth complete; length and stem diameter typical for variety reached45: Inflorescence emergence51 501 Onion bulb begins to elongate53 503 30% of the expected length of flower stem reached55 505 Flower stem at full length; sheath closed57 507 Sheath burst open59 509 First flower petals visible; flowers still closed6: Flowering60 600 First flowers open (sporadically)61 601 Beginning of flowering: 10% of flowers open62 602 20% of flowers open63 603 30% of flowers open64 604 40% of flowers open65 605 Full flowering: 50% of flowers open67 607 Flowering finishing: 70% of petals fallen or dry69 609 End of flowering7: Development of fruit71 701 First capsules formed72 702 20% of capsules formed73 703 30% of capsules formed74 704 40% of capsules formed75 705 50% of capsules formed76 706 60% of capsules formed77 707 70% of capsules formed78 708 80% of capsules formed79 709 Capsule development complete; seeds pale8: Ripening of fruit and seed81 801 Beginning of ripening: 10% of capsules ripe85 805 First capsules bursting89 809 Fully ripe: seeds black and hard9: Senescence92 902 Leaves and shoots beginning to discolour95 905 50% of leaves yellow or dead97 907 Plants or above ground parts dead99 909 Harvested product (seeds)
1 Seed sown 2 Onion sets, shallot and garlic 3 For onions, garlic 4 For leek
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